diff --git a/public/main/inc/lib/AnnouncementManager.php b/public/main/inc/lib/AnnouncementManager.php
index 07b0bc6ea5..36214aa600 100644
--- a/public/main/inc/lib/AnnouncementManager.php
+++ b/public/main/inc/lib/AnnouncementManager.php
@@ -2,7 +2,6 @@
 
 /* For licensing terms, see /license.txt */
 
-use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 use Chamilo\CoreBundle\Entity\AbstractResource;
 use Chamilo\CoreBundle\Entity\ExtraField as ExtraFieldEntity;
 use Chamilo\CoreBundle\Entity\ExtraFieldValues;
@@ -11,6 +10,9 @@ use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CoreBundle\Security\Authorization\Voter\ResourceNodeVoter;
 use Chamilo\CourseBundle\Entity\CAnnouncement;
 use Chamilo\CourseBundle\Entity\CAnnouncementAttachment;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 /**
  * Include file with functions for the announcements module.
@@ -496,25 +498,25 @@ class AnnouncementManager
             (1 === (int) api_get_course_setting('allow_user_edit_announcement') && !api_is_anonymous())
         ) {
             $modify_icons = "<a href=\"".$url."&action=modify&id=".$id."\">".
-                Display::return_icon('edit.png', get_lang('Edit'), '', ICON_SIZE_SMALL)."</a>";
+                Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit'))."</a>";
 
-            $image_visibility = 'invisible';
+            $image_visibility = StateIcon::INACTIVE;
             $alt_visibility = get_lang('Visible');
             $setNewStatus = 'visible';
             if ($isVisible) {
-                $image_visibility = 'visible';
+                $image_visibility = StateIcon::ACTIVE;
                 $alt_visibility = get_lang('Hide');
                 $setNewStatus = 'invisible';
             }
             $modify_icons .= "<a
                 href=\"".$url."&action=set_visibility&status=".$setNewStatus."&id=".$id."&sec_token=".$stok."\">".
-                Display::return_icon($image_visibility.'.png', $alt_visibility, '', ICON_SIZE_SMALL)."</a>";
+                Display::getMdiIcon($image_visibility, 'ch-tool-icon', null, ICON_SIZE_SMALL, $alt_visibility)."</a>";
 
             if (api_is_allowed_to_edit(false, true)) {
                 $modify_icons .= "<a
                     href=\"".$url."&action=delete&id=".$id."&sec_token=".$stok."\"
                     onclick=\"javascript:if(!confirm('".addslashes(api_htmlentities(get_lang('Please confirm your choice'), ENT_QUOTES))."')) return false;\">".
-                    Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL).
+                    Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).
                     "</a>";
             }
             $html .= "<tr><th style='text-align:right'>$modify_icons</th></tr>";
@@ -563,18 +565,13 @@ class AnnouncementManager
                 $url = $repo->getResourceFileDownloadUrl($attachment).'?'.api_get_cidreq();
                 $html .= '<tr><td>';
                 $html .= '<br/>';
-                $html .= Display::getMdiIcon('paperclip');
+                $html .= Display::getMdiIcon(ObjectIcon::ATTACHMENT, 'ch-tool-icon', null, ICON_SIZE_SMALL);
                 $html .= '<a href="'.$url.' "> '.$attachment->getFilename().' </a>';
                 $html .= ' - <span class="forum_attach_comment" >'.$attachment->getComment().'</span>';
                 if (api_is_allowed_to_edit(false, true)) {
                     $url = $deleteUrl."&id_attach=".$attachmentId."&sec_token=".$stok;
                     $html .= Display::url(
-                        Display::return_icon(
-                            'delete.png',
-                            get_lang('Delete'),
-                            '',
-                            16
-                        ),
+                        Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Delete')),
                         $url
                     );
                 }
@@ -1407,8 +1404,8 @@ class AnnouncementManager
         $displayed = [];
 
         $actionUrl = api_get_path(WEB_CODE_PATH).'announcements/announcements.php?'.api_get_cidreq();
-        $emailIcon = '<i class="fa fa-envelope-o" title="'.get_lang('Announcement sent by e-mail').'"></i>';
-        $attachmentIcon = '<i class="fa fa-paperclip" title="'.get_lang('Attachment').'"></i>';
+        $emailIcon = Display::getMdiIcon(StateIcon::MAIL_NOTIFICATION, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Announcement sent by e-mail'));
+        $attachmentIcon = Display::getMdiIcon(ObjectIcon::ATTACHMENT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Attachment'));
 
         $editIcon = Display::getMdiIcon(
             ActionIcon::EDIT,
@@ -1620,7 +1617,7 @@ class AnnouncementManager
                     $iterator++;
                 } else {
                     $modify_icons = Display::url(
-                        Display::return_icon('default.png'),
+                        Display::getMdiIcon(ObjectIcon::DEFAULT, 'ch-tool-icon', null, ICON_SIZE_SMALL),
                         $actionUrl.'&action=view&id='.$announcementId
                     );
                 }
diff --git a/public/main/inc/lib/ExerciseCategoryManager.php b/public/main/inc/lib/ExerciseCategoryManager.php
index e7aa2ffb9a..aa76c53780 100644
--- a/public/main/inc/lib/ExerciseCategoryManager.php
+++ b/public/main/inc/lib/ExerciseCategoryManager.php
@@ -3,6 +3,7 @@
 
 use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CourseBundle\Entity\CExerciseCategory;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * Class ExtraFieldValue
@@ -176,8 +177,8 @@ class ExerciseCategoryManager extends Model
     public function getJqgridActionLinks($token)
     {
         //With this function we can add actions to the jgrid (edit, delete, etc)
-        $editIcon = Display::return_icon('edit.png', get_lang('Edit'), '', ICON_SIZE_SMALL);
-        $deleteIcon = Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL);
+        $editIcon = Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit'));
+        $deleteIcon = Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete'));
         $confirmMessage = addslashes(
             api_htmlentities(get_lang('Please confirm your choice'), ENT_QUOTES)
         );
@@ -258,20 +259,10 @@ JAVASCRIPT;
         // Action links
         $content = '<div class="actions">';
         $content .= '<a href="'.api_get_path(WEB_CODE_PATH).'exercise/exercise.php?'.api_get_cidreq().'">';
-        $content .= Display::return_icon(
-            'back.png',
-            get_lang('Back to').' '.get_lang('Administration'),
-            '',
-            ICON_SIZE_MEDIUM
-        );
+        $content .= Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back to').' '.get_lang('Administration'));
         $content .= '</a>';
         $content .= '<a href="'.api_get_self().'?action=add&'.api_get_cidreq().'">';
-        $content .= Display::return_icon(
-            'add.png',
-            get_lang('Add'),
-            '',
-            ICON_SIZE_MEDIUM
-        );
+        $content .= Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add'));
         $content .= '</a>';
         $content .= '</div>';
 
diff --git a/public/main/inc/lib/MailTemplateManager.php b/public/main/inc/lib/MailTemplateManager.php
index c35e888573..dfec341831 100644
--- a/public/main/inc/lib/MailTemplateManager.php
+++ b/public/main/inc/lib/MailTemplateManager.php
@@ -2,6 +2,7 @@
 /* For licensing terms, see /license.txt */
 
 use Symfony\Component\Finder\Finder;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * Class MailTemplateManager.
@@ -53,20 +54,10 @@ class MailTemplateManager extends Model
         // Action links
         $html = '<div class="actions" style="margin-bottom:20px">';
         $html .= '<a href="'.api_get_path(WEB_CODE_PATH).'admin">'.
-            Display::return_icon(
-                'back.png',
-                get_lang('Back'),
-                '',
-                '32'
-            )
+            Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back'))
             .'</a>';
         $html .= '<a href="'.api_get_self().'?action=add">'.
-            Display::return_icon(
-                'add.png',
-                get_lang('Add'),
-                '',
-                '32'
-            ).'</a>';
+            Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add')).'</a>';
         $html .= '</div>';
         $html .= Display::grid_html('mail_template');
 
diff --git a/public/main/inc/lib/ScheduledAnnouncement.php b/public/main/inc/lib/ScheduledAnnouncement.php
index 09b0cbc007..8e8cb5cb39 100644
--- a/public/main/inc/lib/ScheduledAnnouncement.php
+++ b/public/main/inc/lib/ScheduledAnnouncement.php
@@ -4,6 +4,7 @@
 
 use Chamilo\CoreBundle\Entity\Session;
 use Chamilo\CoreBundle\Entity\User;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * Config setting:
@@ -62,14 +63,14 @@ class ScheduledAnnouncement extends Model
         // action links
         $action = '<div class="actions" style="margin-bottom:20px">';
         $action .= Display::url(
-            Display::return_icon('back.png', get_lang('Back'), '', ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')),
             api_get_path(WEB_CODE_PATH).'session/resume_session.php?id_session='.$sessionId
         );
 
         $action .= '<a href="'.api_get_self().'?action=add&session_id='.$sessionId.'">'.
-            Display::return_icon('add.png', get_lang('Add'), '', ICON_SIZE_MEDIUM).'</a>';
+            Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add')).'</a>';
         $action .= '<a href="scheduled_announcement.php?action=run&session_id='.$sessionId.'">'.
-            Display::return_icon('tuning.png', get_lang('Send pending announcements manually'), '', ICON_SIZE_MEDIUM).
+            Display::getMdiIcon(ActionIcon::SEND_MESSAGE, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Send pending announcements manually')).
             '</a>';
 
         $action .= '</div>';
diff --git a/public/main/inc/lib/SkillModel.php b/public/main/inc/lib/SkillModel.php
index ba6c0acad6..0ac368104d 100644
--- a/public/main/inc/lib/SkillModel.php
+++ b/public/main/inc/lib/SkillModel.php
@@ -24,6 +24,7 @@ use Chamilo\CourseBundle\Entity\CStudentPublication;
 use Chamilo\CourseBundle\Entity\CSurvey;
 use Fhaculty\Graph\Graph;
 use Fhaculty\Graph\Vertex;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 class SkillModel extends Model
 {
@@ -1839,12 +1840,7 @@ class SkillModel extends Model
     public function getToolBar()
     {
         $toolbar = Display::url(
-            Display::return_icon(
-                'back.png',
-                get_lang('Manage skills'),
-                null,
-                ICON_SIZE_MEDIUM
-            ),
+            Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Manage skills')),
             api_get_path(WEB_CODE_PATH).'skills/skill_list.php'
         );
 
diff --git a/public/main/inc/lib/TicketManager.php b/public/main/inc/lib/TicketManager.php
index 3c0a2fc20c..7fea2535fb 100644
--- a/public/main/inc/lib/TicketManager.php
+++ b/public/main/inc/lib/TicketManager.php
@@ -12,6 +12,7 @@ use Chamilo\CoreBundle\Entity\User;
 use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CourseBundle\Entity\CLp;
 use Symfony\Component\HttpFoundation\File\UploadedFile;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
 
 /**
  * Class TicketManager.
@@ -958,26 +959,28 @@ class TicketManager
 
             switch ($row['source']) {
                 case self::SOURCE_PRESENTIAL:
-                    $img_source = 'icons/32/user.png';
+                    $img_source = ObjectIcon::USER;
                     break;
                 case self::SOURCE_EMAIL:
-                    $img_source = 'icons/32/mail.png';
+                    $img_source = ObjectIcon::EMAIL;
                     break;
                 case self::SOURCE_PHONE:
-                    $img_source = 'icons/32/event.png';
+                    $img_source = ObjectIcon::PHONE;
                     break;
                 default:
-                    $img_source = 'icons/32/ticket.png';
+                    $img_source = ObjectIcon::TICKET;
                     break;
             }
 
             $row['start_date'] = Display::dateToStringAgoAndLongDate($row['start_date']);
             $row['sys_lastedit_datetime'] = Display::dateToStringAgoAndLongDate($row['sys_lastedit_datetime']);
 
-            $icon = Display::return_icon(
+            $icon = Display::getMdiIcon(
                 $img_source,
+                'ch-tool-icon',
+                'margin-right: 10px; float: left;',
+                ICON_SIZE_SMALL,
                 get_lang('Information'),
-                ['style' => 'margin-right: 10px; float: left;']
             );
 
             $icon .= '<a href="ticket_details.php?ticket_id='.$row['id'].'">'.$row['code'].'</a>';
@@ -1281,7 +1284,7 @@ class TicketManager
                         message.ticket_id = '$ticketId' ";
             $result = Database::query($sql);
             $ticket['messages'] = [];
-            $attach_icon = Display::return_icon('attachment.gif', '');
+            $attach_icon = Display::getMdiIcon(ObjectIcon::ATTACHMENT, 'ch-tool-icon', null, ICON_SIZE_SMALL);
 
             while ($row = Database::fetch_assoc($result)) {
                 $message = $row;
diff --git a/public/main/inc/lib/agenda.lib.php b/public/main/inc/lib/agenda.lib.php
index 6a5c4ba0b5..93fa083f95 100644
--- a/public/main/inc/lib/agenda.lib.php
+++ b/public/main/inc/lib/agenda.lib.php
@@ -10,6 +10,9 @@ use Chamilo\CourseBundle\Entity\CCalendarEvent;
 use Chamilo\CourseBundle\Entity\CCalendarEventAttachment;
 use Chamilo\CourseBundle\Entity\CGroup;
 use Symfony\Component\HttpFoundation\File\UploadedFile;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+
 
 /**
  * Class Agenda.
@@ -1649,7 +1652,10 @@ class Agenda
             $event['attachment'] = '';
             if (!empty($attachmentList)) {
                 $icon = Display::getMdiIcon(
-                    'paperclip'
+                    ObjectIcon::ATTACHMENT,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_SMALL
                 );
                 /** @var CCalendarEventAttachment $attachment */
                 foreach ($attachmentList as $attachment) {
@@ -2546,11 +2552,11 @@ class Agenda
 
         $actionsLeft = '';
         $actionsLeft .= Display::url(
-            Display::return_icon('calendar.png', get_lang('Calendar'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ObjectIcon::AGENDA, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Calendar')),
             $codePath."calendar/agenda_js.php?type={$this->type}&$cidReq"
         );
         $actionsLeft .= Display::url(
-            Display::return_icon('week.png', get_lang('Agenda list'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ObjectIcon::AGENDA_WEEK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Agenda list')),
             $codePath."calendar/agenda_list.php?type={$this->type}&$cidReq"
         );
 
@@ -2564,12 +2570,12 @@ class Agenda
             )
         ) {
             $actionsLeft .= Display::url(
-                Display::return_icon('new_event.png', get_lang('Add event'), [], ICON_SIZE_MEDIUM),
+                Display::getMdiIcon(ObjectIcon::AGENDA_EVENT, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add event')),
                 $codePath."calendar/agenda.php?action=add&type={$this->type}&$cidReq"
             );
 
             $actionsLeft .= Display::url(
-                Display::return_icon('import_calendar.png', get_lang('Outlook import'), [], ICON_SIZE_MEDIUM),
+                Display::getMdiIcon(ActionIcon::IMPORT_ARCHIVE, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Outlook import')),
                 $codePath."calendar/agenda.php?action=importical&type={$this->type}&$cidReq"
             );
 
@@ -2596,13 +2602,13 @@ class Agenda
 
         if ('personal' === $this->type && !api_is_anonymous()) {
             $actionsLeft .= Display::url(
-                Display::return_icon('1day.png', get_lang('Sessions plan calendar'), [], ICON_SIZE_MEDIUM),
+                Display::getMdiIcon(ObjectIcon::AGENDA_PLAN, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Sessions plan calendar')),
                 $codePath."calendar/planification.php"
             );
 
             if (api_is_student_boss() || api_is_platform_admin()) {
                 $actionsLeft .= Display::url(
-                    Display::return_icon('calendar-user.png', get_lang('MyStudentsSchedule'), [], ICON_SIZE_MEDIUM),
+                    Display::getMdiIcon(ObjectIcon::AGENDA_USER_EVENT, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('MyStudentsSchedule')),
                     $codePath.'my_space/calendar_plan.php'
                 );
             }
@@ -3321,7 +3327,7 @@ class Agenda
                 if (($curday > 0) && ($curday <= $numberofdays[$month])) {
                     $bgcolor = $class = 'class="days_week"';
                     $dayheader = Display::div(
-                        $curday,
+                        strval($curday),
                         ['class' => 'agenda_day']
                     );
                     if (($curday == $today['mday']) && ($year == $today['year']) && ($month == $today['mon'])) {
@@ -3359,48 +3365,40 @@ class Agenda
                             switch ($value['calendar_type']) {
                                 case 'personal':
                                     $bg_color = '#D0E7F4';
-                                    $icon = Display::return_icon(
-                                        'user.png',
-                                        get_lang('Personal agenda'),
-                                        [],
-                                        ICON_SIZE_SMALL
-                                    );
+                                    $icon = Display::getMdiIcon(ObjectIcon::USER, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Personal agenda'));
                                     break;
                                 case 'global':
                                     $bg_color = '#FFBC89';
-                                    $icon = Display::return_icon(
-                                        'view_remove.png',
-                                        get_lang('Platform event'),
-                                        [],
-                                        ICON_SIZE_SMALL
-                                    );
+                                    $icon = Display::getMdiIcon(ObjectIcon::AGENDA_PLATFORM_EVENT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Platform event'));
                                     break;
                                 case 'course':
                                     $bg_color = '#CAFFAA';
-                                    $icon_name = 'course.png';
+                                    $icon_name = ObjectIcon::COURSE;
                                     if (!empty($value['session_id'])) {
-                                        $icon_name = 'session.png';
+                                        $icon_name = ObjectIcon::SESSION;
                                     }
                                     if ($show_content) {
                                         $icon = Display::url(
-                                            Display::return_icon(
+                                            Display::getMdiIcon(
                                                 $icon_name,
+                                                'ch-tool-icon',
+                                                null,
+                                                ICON_SIZE_SMALL,
                                                 $value['course_name'].' '.get_lang(
                                                     'Course'
-                                                ),
-                                                [],
-                                                ICON_SIZE_SMALL
+                                                )
                                             ),
                                             $value['url']
                                         );
                                     } else {
-                                        $icon = Display::return_icon(
+                                        $icon = Display::getMdiIcon(
                                             $icon_name,
+                                            'ch-tool-icon',
+                                            null,
+                                            ICON_SIZE_SMALL,
                                             $value['course_name'].' '.get_lang(
                                                 'Course'
-                                            ),
-                                            [],
-                                            ICON_SIZE_SMALL
+                                            )
                                         );
                                     }
                                     break;
diff --git a/public/main/inc/lib/api.lib.php b/public/main/inc/lib/api.lib.php
index c6d2e15060..bd200c1752 100644
--- a/public/main/inc/lib/api.lib.php
+++ b/public/main/inc/lib/api.lib.php
@@ -20,6 +20,8 @@ use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 use Symfony\Component\Security\Core\User\UserInterface;
 use ZipStream\Option\Archive;
 use ZipStream\ZipStream;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
 
 /**
  * This is a code library for Chamilo.
@@ -2188,14 +2190,11 @@ function api_format_course_array(Course $course = null)
     $courseData['about_url'] = $coursePath.$courseData['real_id'].'/about';
     $courseData['add_teachers_to_sessions_courses'] = $course->isAddTeachersToSessionsCourses();
 
-    $image = Display::return_icon(
-        'course.png',
+    $image = Display::getMdiIcon(
+        ObjectIcon::COURSE,
+        'ch-tool-icon',
         null,
-        null,
-        ICON_SIZE_BIG,
-        null,
-        true,
-        false
+        ICON_SIZE_BIG
     );
 
     $illustration = Container::getIllustrationRepository()->getIllustrationUrl($course);
@@ -2529,11 +2528,12 @@ function api_get_session_image($sessionId, User $user)
     if (!$user->hasRole('ROLE_STUDENT')) {
         // Check whether is not a student
         if ($sessionId > 0) {
-            $image = '&nbsp;&nbsp;'.Display::return_icon(
-                'star.png',
-                get_lang('Session-specific resource'),
-                ['align' => 'absmiddle'],
-                ICON_SIZE_SMALL
+            $image = '&nbsp;&nbsp;'.Display::getMdiIcon(
+                ObjectIcon::STAR,
+                'ch-tool-icon',
+                'align:absmiddle;',
+                ICON_SIZE_SMALL,
+                get_lang('Session-specific resource')
             );
         }
     }
@@ -3811,10 +3811,12 @@ function api_time_to_hms($seconds, $space = ':', $showSeconds = true, $roundMinu
     if (-1 == $seconds) {
         return
             get_lang('Unknown').
-            Display::return_icon(
-                'info2.gif',
-                get_lang('The datas about this user were registered when the calculation of time spent on the platform wasn\'t possible.'),
-                ['align' => 'absmiddle', 'hspace' => '3px']
+            Display::getMdiIcon(
+                ActionIcon::INFORMATION,
+                'ch-tool-icon',
+                'align: absmiddle; hspace: 3px',
+                ICON_SIZE_SMALL,
+                get_lang('The datas about this user were registered when the calculation of time spent on the platform wasn\'t possible.')
             );
     }
 
diff --git a/public/main/inc/lib/attendance.lib.php b/public/main/inc/lib/attendance.lib.php
index 51a845303c..8512dbb9b7 100644
--- a/public/main/inc/lib/attendance.lib.php
+++ b/public/main/inc/lib/attendance.lib.php
@@ -10,6 +10,9 @@ use Chamilo\CourseBundle\Entity\CAttendance;
 use Chamilo\CourseBundle\Entity\CAttendanceCalendar;
 use Chamilo\CourseBundle\Entity\CAttendanceSheetLog;
 use Doctrine\Common\Collections\Criteria;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 class Attendance
 {
@@ -212,40 +215,40 @@ class Attendance
                 $actions .= '<center>';
                 if (api_is_platform_admin()) {
                     $actions .= '<a href="index.php?'.api_get_cidreq().'&action=attendance_edit&attendance_id='.$id.'">'.
-                        Display::return_icon('edit.png', get_lang('Edit'), [], ICON_SIZE_SMALL).'</a>&nbsp;';
+                        Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')).'</a>&nbsp;';
                     // Visible
                     if (1 == $active) {
                         $actions .= '<a href="index.php?'.api_get_cidreq().'&action=attendance_set_invisible&attendance_id='.$id.'">'.
-                            Display::return_icon('visible.png', get_lang('Hide'), [], ICON_SIZE_SMALL).'</a>';
+                            Display::getMdiIcon(StateIcon::ACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Hide')).'</a>';
                     } else {
                         $actions .= '<a href="index.php?'.api_get_cidreq().'&action=attendance_set_visible&attendance_id='.$id.'">'.
-                            Display::return_icon('invisible.png', get_lang('Show'), [], ICON_SIZE_SMALL).'</a>';
+                            Display::getMdiIcon(StateIcon::INACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Show')).'</a>';
                         $row[2] = '<span class="muted">'.$attendance->getDescription().'</span>';
                     }
                     if ('true' === $allowDelete) {
                         $actions .= '<a href="index.php?'.api_get_cidreq().'&action=attendance_delete&attendance_id='.$id.'">'.
-                            Display::return_icon('delete.png', get_lang('Delete'), [], ICON_SIZE_SMALL).'</a>';
+                            Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
                     }
                 } else {
                     $is_locked_attendance = self::is_locked_attendance($id);
                     if ($is_locked_attendance) {
-                        $actions .= Display::return_icon('edit_na.png', get_lang('Edit')).'&nbsp;';
-                        $actions .= Display::return_icon('visible.png', get_lang('Hide'));
+                        $actions .= Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Edit')).'&nbsp;';
+                        $actions .= Display::getMdiIcon(StateIcon::ACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Hide'));
                     } else {
                         $actions .= '<a href="index.php?'.api_get_cidreq().'&action=attendance_edit&attendance_id='.$id.'">'.
-                            Display::return_icon('edit.png', get_lang('Edit'), [], ICON_SIZE_SMALL).'</a>&nbsp;';
+                            Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')).'</a>&nbsp;';
 
                         if (1 == $active) {
                             $actions .= ' <a href="index.php?'.api_get_cidreq().'&action=attendance_set_invisible&attendance_id='.$id.'">'.
-                                Display::return_icon('visible.png', get_lang('Hide'), [], ICON_SIZE_SMALL).'</a>';
+                                Display::getMdiIcon(StateIcon::ACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Hide')).'</a>';
                         } else {
                             $actions .= ' <a href="index.php?'.api_get_cidreq().'&action=attendance_set_visible&attendance_id='.$id.'">'.
-                                Display::return_icon('invisible.png', get_lang('Show'), [], ICON_SIZE_SMALL).'</a>';
+                                Display::getMdiIcon(StateIcon::INACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Show')).'</a>';
                             $row[2] = '<span class="muted">'.$attendance->getDescription().'</span>';
                         }
                         if ('true' === $allowDelete) {
                             $actions .= ' <a href="index.php?'.api_get_cidreq().'&action=attendance_delete&attendance_id='.$id.'">'.
-                                Display::return_icon('delete.png', get_lang('Delete'), [], ICON_SIZE_SMALL).'</a>';
+                                Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
                         }
                     }
                 }
@@ -264,15 +267,15 @@ class Attendance
                         $actions .= '&nbsp;<a
                             onclick="javascript:if(!confirm(\''.$message_alert.'\')) return false;"
                             href="index.php?'.api_get_cidreq().'&action=lock_attendance&attendance_id='.$id.'">'.
-                            Display::return_icon('unlock.png', get_lang('Lock attendance')).'</a>';
+                            Display::getMdiIcon(ActionIcon::UNLOCK, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Lock attendance')).'</a>';
                     } else {
                         if (api_is_platform_admin()) {
                             $actions .= '&nbsp;<a
                             onclick="javascript:if(!confirm(\''.get_lang('Are you sure you want to unlock the attendance?').'\')) return false;"
                             href="index.php?'.api_get_cidreq().'&action=unlock_attendance&attendance_id='.$id.'">'.
-                                    Display::return_icon('lock.png', get_lang('Unlock attendance')).'</a>';
+                                    Display::getMdiIcon(ActionIcon::LOCK, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Unlock attendance')).'</a>';
                         } else {
-                            $actions .= '&nbsp;'.Display::return_icon('locked_na.png', get_lang('Locked attendance'));
+                            $actions .= '&nbsp;'.Display::getMdiIcon(ActionIcon::LOCK, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Locked attendance'));
                         }
                     }
                 }
@@ -2580,12 +2583,12 @@ class Attendance
                 $actionsLeft = '<a
                     style="float:left;"
                     href="index.php?'.api_get_cidreq().'&action=calendar_list&attendance_id='.$attendanceId.'">'.
-                    Display::return_icon('attendance_calendar.png', get_lang('Attendance calendar'), '', ICON_SIZE_MEDIUM).
+                    Display::getMdiIcon(ObjectIcon::AGENDA, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Attendance calendar')).
                     '</a>';
                 $actionsLeft .= '<a
                     id="pdf_export" style="float:left;"
                     href="index.php?'.api_get_cidreq().'&action=attendance_sheet_export_to_pdf&attendance_id='.$attendanceId.'&filter='.$default_filter.'&group_id='.$groupId.'">'.
-                    Display::return_icon('pdf.png', get_lang('Export to PDF'), '', ICON_SIZE_MEDIUM).'</a>';
+                    Display::getMdiIcon(ActionIcon::EXPORT_PDF, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Export to PDF')).'</a>';
 
                 $actionsRight = $form->returnForm();
                 $content .= Display::toolbarAction('toolbar-attendance', [$actionsLeft, $actionsRight]);
@@ -2677,11 +2680,7 @@ class Attendance
                         $time = $calendar['time'];
                         $datetime = '<div class="grey">'.$date.' - '.$time.'</div>';
 
-                        $img_lock = Display::return_icon(
-                            'lock-closed.png',
-                            get_lang('Unlock date'),
-                            ['class' => 'img_lock', 'id' => 'datetime_column_'.$calendarId]
-                        );
+                        $img_lock = Display::getMdiIcon(ActionIcon::LOCK, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Unlock date'));
 
                         if (!empty($calendar['done_attendance'])) {
                             $datetime = '<div class="blue">'.$date.' - '.$time.'</div>';
@@ -2695,11 +2694,7 @@ class Attendance
                                 id="hidden_input_'.$calendarId.'" name="hidden_input[]"
                                 value="'.$calendarId.'" />';
                             $disabled_check = '';
-                            $img_lock = Display::return_icon(
-                                'lock-closed.png',
-                                get_lang('Lock date'),
-                                ['class' => 'img_unlock', 'id' => 'datetime_column_'.$calendarId]
-                            );
+                            $img_lock = Display::getMdiIcon(ActionIcon::LOCK, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Lock date'));
                         }
 
                         $result .= '<th>';
@@ -2725,12 +2720,7 @@ class Attendance
                 } else {
                     $result = '<th width="2000px"><span>
                     <a href="index.php?'.api_get_cidreq().'&action=calendar_list&attendance_id='.$attendanceId.'">';
-                    $result .= Display::return_icon(
-                            'attendance_calendar.png',
-                            get_lang('Attendance calendar'),
-                            '',
-                            ICON_SIZE_MEDIUM
-                        ).' '.get_lang('Go to the attendance calendar');
+                    $result .= Display::getMdiIcon(ObjectIcon::AGENDA, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Attendance calendar')).' '.get_lang('Go to the attendance calendar');
                     $result .= '</a></span></th>';
                 }
 
@@ -2791,26 +2781,16 @@ class Attendance
                                     value="'.$user['user_id'].'" '.$disabled.' '.$checked.' />';
                                     $form .= '<span class="anchor_'.$calendar['iid'].'"></span>';
                                 } else {
-                                    $form .= $presence ? Display::return_icon(
-                                        'checkbox_on.png',
-                                        get_lang('Assistance'),
-                                        null,
-                                        ICON_SIZE_TINY
-                                    ) : Display::return_icon(
-                                        'checkbox_off.png',
-                                        get_lang('Assistance'),
-                                        null,
-                                        ICON_SIZE_TINY
-                                    );
+                                    $form .= $presence ? Display::getMdiIcon(StateIcon::CHECKBOX_MARKED, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Assistance')) : Display::getMdiIcon(StateIcon::CHECKBOX_BLANK, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Assistance'));
                                 }
                             } else {
                                 switch ($presence) {
                                     case 1:
-                                        $form .= Display::return_icon('accept.png', get_lang('Attended'));
+                                        $form .= Display::getMdiIcon(StateIcon::CHECKBOX_BLANK, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Attended'));
 
                                         break;
                                     case 0:
-                                        $form .= Display::return_icon('exclamation.png', get_lang('Not attended'));
+                                        $form .= Display::getMdiIcon(StateIcon::CHECKBOX_MARKED, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Not attended'));
 
                                         break;
                                     case -1:
@@ -2894,7 +2874,7 @@ class Attendance
                         $class = 'row_odd';
                     }
 
-                    $check = $presence['presence'] ? Display::return_icon('checkbox_on.png', get_lang('Assistance'), null, ICON_SIZE_TINY) : Display::return_icon('checkbox_off.png', get_lang('Assistance'), null, ICON_SIZE_TINY);
+                    $check = $presence['presence'] ? Display::getMdiIcon(StateIcon::CHECKBOX_MARKED, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Assistance')) : Display::getMdiIcon(StateIcon::CHECKBOX_BLANK, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Assistance'));
                     $content .= '<tr class="'.$class.'">
                             <td>
                                 '.$check.'&nbsp; '.$presence['date_time'].'
diff --git a/public/main/inc/lib/banner.lib.php b/public/main/inc/lib/banner.lib.php
index e0fbdcb8a6..a242e7899f 100644
--- a/public/main/inc/lib/banner.lib.php
+++ b/public/main/inc/lib/banner.lib.php
@@ -3,6 +3,7 @@
 
 use Chamilo\CoreBundle\Component\Utils\ChamiloApi;
 use ChamiloSession as Session;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
 
 /**
  * Code.
@@ -125,7 +126,7 @@ function returnNotificationMenu()
         ) {
             $html .= '<li class="user-online"><a href="'.api_get_path(WEB_PATH).'whoisonline.php" target="_self" title="'
                 .get_lang('Users online').'" >'
-                .Display::return_icon('user.png', get_lang('Users online'), [], ICON_SIZE_TINY)
+                .Display::getMdiIcon(ObjectIcon::USER, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Users online'))
                 .' '.$number.'</a></li>';
         }
 
@@ -138,7 +139,7 @@ function returnNotificationMenu()
         ) {
             $html .= '<li class="user-online-course"><a href="'.api_get_path(WEB_PATH).'whoisonline.php?cidReq='.$courseInfo['sysCode']
                 .'" target="_self">'
-                .Display::return_icon('course.png', get_lang('Users online').' '.get_lang('in this course'), [], ICON_SIZE_TINY)
+                .Display::getMdiIcon(ObjectIcon::COURSE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Users online').' '.get_lang('in this course'), [], ICON_SIZE_TINY)
                 .' '.$number_online_in_course.' </a></li>';
         }
 
@@ -150,7 +151,7 @@ function returnNotificationMenu()
                 $numberOnlineInSession = getOnlineUsersInSessionCount($sessionId);
                 $html .= '<li class="user-online-session">
                             <a href="'.api_get_path(WEB_PATH).'whoisonlinesession.php" target="_self">'
-                            .Display::return_icon('session.png', get_lang('Online in my sessions'), [], ICON_SIZE_TINY)
+                            .Display::getMdiIcon(ObjectIcon::SESSION, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Online in my sessions'))
                             .' '.$numberOnlineInSession.'</a></li>';
             }
         }
@@ -357,29 +358,26 @@ function return_breadcrumb($interbreadcrumb, $language_file, $nameTools)
 
         switch (api_get_setting('breadcrumbs_course_homepage')) {
             case 'get_lang':
-                $itemTitle = Display::return_icon(
-                    'home.png',
-                    get_lang('Course home'),
-                    [],
-                    ICON_SIZE_TINY
-                );
+                $itemTitle = Display::getMdiIcon(ObjectIcon::HOME, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Course home'));
                 break;
             case 'course_code':
-                $itemTitle = Display::return_icon(
-                    'home.png',
-                    $courseInfo['official_code'],
-                    [],
-                    ICON_SIZE_TINY
+                $itemTitle = Display::getMdiIcon(
+                    ObjectIcon::HOME,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_TINY,
+                    $courseInfo['official_code']
                 )
                 .' '.$courseInfo['official_code'];
                 break;
             case 'session_name_and_course_title':
             default:
-                $itemTitle = Display::return_icon(
-                    'home.png',
-                    $courseInfo['name'].$sessionName,
-                    [],
-                    ICON_SIZE_TINY
+                $itemTitle = Display::getMdiIcon(
+                    ObjectIcon::HOME,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_TINY,
+                    $courseInfo['name'].$sessionName
                 )
                 .' '.$course_title.$sessionName;
 
diff --git a/public/main/inc/lib/career.lib.php b/public/main/inc/lib/career.lib.php
index d67676e1d6..69d8463d00 100644
--- a/public/main/inc/lib/career.lib.php
+++ b/public/main/inc/lib/career.lib.php
@@ -4,6 +4,7 @@
 use Chamilo\CoreBundle\Entity\Career as CareerEntity;
 use Fhaculty\Graph\Graph;
 use Fhaculty\Graph\Vertex;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 class Career extends Model
 {
@@ -76,10 +77,10 @@ class Career extends Model
     public function display()
     {
         $actions = '<a href="career_dashboard.php">'.
-            Display::return_icon('back.png', get_lang('Back'), '', ICON_SIZE_MEDIUM).'</a>';
+            Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')).'</a>';
         if (api_is_platform_admin()) {
             $actions .= '<a href="'.api_get_self().'?action=add">'.
-                    Display::return_icon('new_career.png', get_lang('Add'), '', ICON_SIZE_MEDIUM).'</a>';
+                    Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add')).'</a>';
         }
         $html = Display::toolbarAction('career_actions', [$actions]);
         $html .= Display::grid_html('careers');
diff --git a/public/main/inc/lib/course.lib.php b/public/main/inc/lib/course.lib.php
index 3d394cbff8..e17c3e5d83 100644
--- a/public/main/inc/lib/course.lib.php
+++ b/public/main/inc/lib/course.lib.php
@@ -16,6 +16,8 @@ use Chamilo\CourseBundle\Component\CourseCopy\CourseRestorer;
 use Chamilo\CourseBundle\Entity\CGroup;
 use ChamiloSession as Session;
 use Doctrine\Common\Collections\Criteria;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
 
 /**
  * Class CourseManager.
@@ -2091,7 +2093,7 @@ class CourseManager
                     $html .= '<ul class="user-teacher">';
                     foreach ($list as $teacher) {
                         $html .= '<li>';
-                        $html .= Display::return_icon('teacher.png', '', null, ICON_SIZE_TINY);
+                        $html .= Display::getMdiIcon(ObjectIcon::TEACHER, 'ch-tool-icon', null, ICON_SIZE_TINY);
                         $html .= ' '.$teacher;
                         $html .= '</li>';
                     }
@@ -2198,11 +2200,12 @@ class CourseManager
                 foreach ($course_coachs as $coachs) {
                     $html .= Display::tag(
                         'li',
-                        Display::return_icon(
-                            'teacher.png',
-                            get_lang('Coach'),
+                        Display::getMdiIcon(
+                            ObjectIcon::TEACHER,
+                            'ch-tool-icon',
                             null,
-                            ICON_SIZE_TINY
+                            ICON_SIZE_TINY,
+                            get_lang('Coach')
                         ).' '.$coachs
                     );
                 }
@@ -3168,19 +3171,22 @@ class CourseManager
                                 ENT_QUOTES,
                         $charset
                     )).'\')) return false;">';
-                    $data .= Display::return_icon(
-                        'delete.gif',
-                        get_lang('Delete'),
-                        ['style' => 'vertical-align:middle;float:right;']
+                    $data .= Display::getMdiIcon(
+                        ActionIcon::DELETE,
+                        'ch-tool-icon',
+                        'vertical-align:middle;float:right;',
+                        ICON_SIZE_SMALL,
+                        get_lang('Delete')
                     );
                     $data .= '</a> ';
                     //edit
                     $data .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&description_id='.$description->id.'">';
-                    $data .= Display::return_icon(
-                        'edit.png',
-                        get_lang('Edit'),
-                        ['style' => 'vertical-align:middle;float:right; padding-right:4px;'],
-                        ICON_SIZE_SMALL
+                    $data .= Display::getMdiIcon(
+                        ActionIcon::EDIT,
+                        'ch-tool-icon',
+                        'vertical-align:middle;float:right; padding-right:4px;',
+                        ICON_SIZE_SMALL,
+                        get_lang('Edit')
                     );
                     $data .= '</a> ';
                 }
@@ -3547,12 +3553,11 @@ class CourseManager
                 $params['status'] = $course_info['status'];
                 $params['category'] = $course_info['categoryName'];
                 $params['category_code'] = $course_info['categoryCode'];
-                $params['icon'] = Display::return_icon(
-                    'drawing-pin.png',
+                $params['icon'] = Display::getMdiIcon(
+                    ObjectIcon::PIN,
+                    'ch-tool-icon',
                     null,
-                    null,
-                    ICON_SIZE_LARGE,
-                    null
+                    ICON_SIZE_LARGE
                 );
 
                 if ('true' == api_get_setting('display_coursecode_in_courselist')) {
@@ -3873,13 +3878,11 @@ class CourseManager
         // Show a hyperlink to the course, unless the course is closed and user is not course admin.
         $session_url = '';
         $params = [];
-        $params['icon'] = Display::return_icon(
-            'session.png',
-            null,
-            [],
-            ICON_SIZE_LARGE,
+        $params['icon'] = Display::getMdiIcon(
+            ObjectIcon::SESSION,
+            'ch-tool-icon',
             null,
-            true
+            ICON_SIZE_LARGE
         );
         $params['real_id'] = $course_info['real_id'];
         $params['visibility'] = $course_info['visibility'];
@@ -3942,10 +3945,10 @@ class CourseManager
         if (!empty($thumbnails)) {
             $params['html_image'] = Display::img($thumbnails, $course_info['name'], ['class' => 'img-responsive']);
         } else {
-            $params['html_image'] = Display::return_icon(
-                'session.png',
-                $course_info['name'],
-                ['class' => 'img-responsive'],
+            $params['html_image'] = Display::getMdiIcon(
+                ObjectIcon::SESSION,
+                'ch-tool-icon img-responsive',
+                null,
                 ICON_SIZE_LARGE,
                 $course_info['name']
             );
@@ -6123,11 +6126,12 @@ class CourseManager
         $course_info['status'] = $course['status'];
 
         // New code displaying the user's status in respect to this course.
-        $status_icon = Display::return_icon(
-            'blackboard.png',
-            $course_info['title'],
-            [],
-            ICON_SIZE_LARGE
+        $status_icon = Display::getMdiIcon(
+            'account-key',
+            'ch-tool-icon',
+            null,
+            ICON_SIZE_LARGE,
+            $course_info['title']
         );
 
         $params = [];
@@ -6135,9 +6139,9 @@ class CourseManager
 
         if (api_is_platform_admin()) {
             if ($loadDirs) {
-                $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), ['align' => 'absmiddle'], ICON_SIZE_SMALL).'</a>';
+                $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::getMdiIcon(ObjectIcon::FOLDER, 'ch-tool-icon', 'align: absmiddle;', ICON_SIZE_SMALL, get_lang('Documents')).'</a>';
                 $params['right_actions'] .= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cid='.$course['real_id'].'">'.
-                    Display::return_icon('edit.png', get_lang('Edit'), ['align' => 'absmiddle'], ICON_SIZE_SMALL).
+                    Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', 'align: absmiddle;', ICON_SIZE_SMALL, get_lang('Edit')).
                     '</a>';
                 $params['right_actions'] .= Display::div(
                     '',
@@ -6155,7 +6159,7 @@ class CourseManager
             if (Course::CLOSED != $course_info['visibility']) {
                 if ($loadDirs) {
                     $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.
-                        Display::return_icon('folder.png', get_lang('Documents'), ['align' => 'absmiddle'], ICON_SIZE_SMALL).'</a>';
+                        Display::getMdiIcon(ObjectIcon::FOLDER, 'ch-tool-icon', 'align: absmiddle;', ICON_SIZE_SMALL, get_lang('Documents')).'</a>';
                     $params['right_actions'] .= Display::div(
                         '',
                         [
diff --git a/public/main/inc/lib/course_category.lib.php b/public/main/inc/lib/course_category.lib.php
index 0417d8ed81..70cea72727 100644
--- a/public/main/inc/lib/course_category.lib.php
+++ b/public/main/inc/lib/course_category.lib.php
@@ -5,6 +5,8 @@
 use Chamilo\CoreBundle\Entity\Asset;
 use Chamilo\CoreBundle\Entity\CourseCategory as CourseCategoryEntity;
 use Chamilo\CoreBundle\Framework\Container;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
 
 class CourseCategory
 {
@@ -15,7 +17,7 @@ class CourseCategory
      *
      * @return array
      */
-    public static function getCategory(string $categoryCode = null)
+    public static function getCategory(string $categoryCode = null): array
     {
         if (!empty($categoryCode)) {
             $table = Database::get_main_table(TABLE_MAIN_CATEGORY);
@@ -381,25 +383,10 @@ class CourseCategory
             $row++;
             $mainUrl = api_get_path(WEB_CODE_PATH).'admin/course_category.php?category='.$categoryCode;
 
-            $editIcon = Display::return_icon(
-                'edit.png',
-                get_lang('Edit'),
-                null,
-                ICON_SIZE_SMALL
-            );
-            $exportIcon = Display::return_icon('export_csv.png', get_lang('ExportAsCSV'), '');
-            $deleteIcon = Display::return_icon(
-                'delete.png',
-                get_lang('Delete'),
-                null,
-                ICON_SIZE_SMALL
-            );
-            $moveIcon = Display::return_icon(
-                'up.png',
-                get_lang('Up in same level'),
-                null,
-                ICON_SIZE_SMALL
-            );
+            $editIcon = Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit'));
+            $exportIcon = Display::getMdiIcon(ActionIcon::EXPORT_CSV, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('ExportAsCSV'), '');
+            $deleteIcon = Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete'));
+            $moveIcon = Display::getMdiIcon(ActionIcon::UP, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Up in same level'));
 
             $urlId = api_get_current_access_url_id();
             foreach ($categories as $category) {
@@ -435,11 +422,12 @@ class CourseCategory
 
                 $url = api_get_path(WEB_CODE_PATH).'admin/course_category.php?id='.$categoryId;
                 $title = Display::url(
-                    Display::return_icon(
-                        'folder_document.gif',
-                        get_lang('Open this category'),
+                    Display::getMdiIcon(
+                        ObjectIcon::FOLDER,
+                        'ch-tool-icon',
                         null,
-                        ICON_SIZE_SMALL
+                        ICON_SIZE_SMALL,
+                        get_lang('Open this category')
                     ).' '.$category->getName().' ('.$code.')',
                     $url
                 );
diff --git a/public/main/inc/lib/diagnoser.lib.php b/public/main/inc/lib/diagnoser.lib.php
index 96b9f0545e..2584c6484f 100644
--- a/public/main/inc/lib/diagnoser.lib.php
+++ b/public/main/inc/lib/diagnoser.lib.php
@@ -2,6 +2,9 @@
 
 /* For licensing terms, see /license.txt */
 
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+
 /**
  * Class Diagnoser
  * Class that is responsible for generating diagnostic information about the system.
@@ -843,8 +846,8 @@ class Diagnoser
         $res = $connection->query('SELECT id, code, directory, disk_quota, last_visit FROM course ORDER BY last_visit DESC, code LIMIT 500');
         $systemPath = api_get_path(SYS_COURSE_PATH);
         $webPath = api_get_path(WEB_COURSE_PATH);
-        $courseHomeIcon = Display::return_icon('home.png', get_lang('CourseHome'));
-        $courseEditIcon = Display::return_icon('edit.png', get_lang('Edit'));
+        $courseHomeIcon = Display::getMdiIcon(ObjectIcon::HOME, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('CourseHome'));
+        $courseEditIcon = Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit'));
         $windows = api_is_windows_os();
         $courseEditPath = api_get_path(WEB_CODE_PATH).'admin/course_edit.php?id=';
         while ($row = $res->fetch()) {
diff --git a/public/main/inc/lib/extra_field.lib.php b/public/main/inc/lib/extra_field.lib.php
index 3e94b0f2f5..78b1f65057 100644
--- a/public/main/inc/lib/extra_field.lib.php
+++ b/public/main/inc/lib/extra_field.lib.php
@@ -7,7 +7,7 @@ use Chamilo\CoreBundle\Entity\ExtraField as EntityExtraField;
 use Chamilo\CoreBundle\Entity\ExtraFieldRelTag;
 use Chamilo\CoreBundle\Entity\Tag;
 use Chamilo\CoreBundle\Framework\Container;
-
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 class ExtraField extends Model
 {
     public const FIELD_TYPE_TEXT = 1;
@@ -1676,7 +1676,7 @@ class ExtraField extends Model
                                     );
 
                                     $linkToDelete = '&nbsp;'.Display::url(
-                                        Display::return_icon('delete.png', get_lang('Delete')),
+                                        Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')),
                                         'javascript:void(0)',
                                         ['id' => $deleteId]
                                     );
@@ -2109,20 +2109,10 @@ class ExtraField extends Model
     public function display()
     {
         $actions = '<a href="../admin/index.php">';
-        $actions .= Display::return_icon(
-            'back.png',
-            get_lang('Back to').' '.get_lang('Administration'),
-            '',
-            ICON_SIZE_MEDIUM
-        );
+        $actions .= Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back to').' '.get_lang('Administration'));
         $actions .= '</a>';
         $actions .= '<a href="'.api_get_self().'?action=add&type='.$this->type.'">';
-        $actions .= Display::return_icon(
-            'add_user_fields.png',
-            get_lang('Add'),
-            '',
-            ICON_SIZE_MEDIUM
-        );
+        $actions .= Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add'));
         $actions .= '</a>';
 
         echo Display::toolbarAction('toolbar', [$actions]);
@@ -2406,8 +2396,8 @@ class ExtraField extends Model
     public function getJqgridActionLinks($token)
     {
         //With this function we can add actions to the jgrid (edit, delete, etc)
-        $editIcon = Display::return_icon('edit.png', get_lang('Edit'), '', ICON_SIZE_SMALL);
-        $deleteIcon = Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL);
+        $editIcon = Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit'));
+        $deleteIcon = Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete'));
         $confirmMessage = addslashes(
             api_htmlentities(get_lang("Please confirm your choice"), ENT_QUOTES)
         );
diff --git a/public/main/inc/lib/extra_field_option.lib.php b/public/main/inc/lib/extra_field_option.lib.php
index 9ff676f080..bbef4a6c12 100644
--- a/public/main/inc/lib/extra_field_option.lib.php
+++ b/public/main/inc/lib/extra_field_option.lib.php
@@ -4,6 +4,7 @@
 
 use Chamilo\CoreBundle\Entity\ExtraFieldOptions;
 use Chamilo\CoreBundle\Framework\Container;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * Handles the extra fields for various objects (users, sessions, courses).
@@ -683,7 +684,7 @@ class ExtraFieldOption extends Model
         echo '<div class="actions">';
         $field_id = isset($_REQUEST['field_id']) ? intval($_REQUEST['field_id']) : null;
         echo '<a href="'.api_get_self().'?action=add&type='.$this->type.'&field_id='.$field_id.'">'.
-                Display::return_icon('add_user_fields.png', get_lang('Add'), '', ICON_SIZE_MEDIUM).'</a>';
+                Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add')).'</a>';
         echo '</div>';
         echo Display::grid_html('extra_field_options');
     }
diff --git a/public/main/inc/lib/glossary.lib.php b/public/main/inc/lib/glossary.lib.php
index 00b3c56048..7d4ea423ff 100644
--- a/public/main/inc/lib/glossary.lib.php
+++ b/public/main/inc/lib/glossary.lib.php
@@ -6,6 +6,9 @@ use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CourseBundle\Entity\CGlossary;
 use ChamiloSession as Session;
 use Doctrine\ORM\NoResultException;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 /**
  * Class GlossaryManager
@@ -471,40 +474,30 @@ class GlossaryManager
         $actionsLeft = '';
         $url = api_get_path(WEB_CODE_PATH).'glossary/index.php?'.api_get_cidreq();
         if (api_is_allowed_to_edit(null, true)) {
-            $addIcon = Display::return_icon(
-                'new_glossary_term.png',
-                get_lang('Add new glossary term'),
-                '',
-                ICON_SIZE_MEDIUM
-            );
+            $addIcon = Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add new glossary term'));
             $actionsLeft .= '<a href="'.$url.'&action=addglossary">'.$addIcon.'</a>';
         }
 
         if (api_is_allowed_to_edit(null, true)) {
             $actionsLeft .= '<a href="'.$url.'&action=import">'.
-                Display::return_icon('import.png', get_lang('Import glossary'), '', ICON_SIZE_MEDIUM).'</a>';
+                Display::getMdiIcon(ActionIcon::IMPORT_ARCHIVE, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Import glossary')).'</a>';
         }
 
         if (!api_is_anonymous()) {
             $actionsLeft .= '<a id="export_opener" href="'.$url.'&action=export">'.
-                Display::return_icon('save.png', get_lang('Export'), '', ICON_SIZE_MEDIUM).'</a>';
+                Display::getMdiIcon(ActionIcon::SAVE_FORM, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Export')).'</a>';
         }
 
         if ('table' === $view || !isset($view)) {
             $actionsLeft .= '<a href="'.$url.'&action=changeview&view=list">'.
-                Display::return_icon('view_detailed.png', get_lang('List view'), '', ICON_SIZE_MEDIUM).'</a>';
+                Display::getMdiIcon(StateIcon::DETAILED_VIEW, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('List view')).'</a>';
         } else {
             $actionsLeft .= '<a href="'.$url.'&action=changeview&view=table">'.
-                Display::return_icon('view_text.png', get_lang('Table view'), '', ICON_SIZE_MEDIUM).'</a>';
+                Display::getMdiIcon(StateIcon::LIST_VIEW, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Table view')).'</a>';
         }
 
         if (api_is_allowed_to_edit(true, true, true)) {
-            $exportIcon = Display::return_icon(
-                'export_to_documents.png',
-                get_lang('Export latest version of this page to Documents'),
-                [],
-                ICON_SIZE_MEDIUM
-            );
+            $exportIcon = Display::getMdiIcon(ActionIcon::EXPORT_DOC, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Export latest version of this page to Documents'));
             $actionsLeft .= Display::url(
                 $exportIcon,
                 $url.'&'.http_build_query(['action' => 'export_documents'])
@@ -518,12 +511,12 @@ class GlossaryManager
         if (!api_is_allowed_to_edit(true, true, true)) {
             if ('ASC' === $orderList) {
                 $actionsLeft .= Display::url(
-                    Display::return_icon('falling.png', get_lang('Sort Descending'), [], ICON_SIZE_MEDIUM),
+                    Display::getMdiIcon(ActionIcon::DOWN, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Sort Descending')),
                     $url.'&'.http_build_query(['order' => 'DESC'])
                 );
             } else {
                 $actionsLeft .= Display::url(
-                    Display::return_icon('upward.png', get_lang('Sort Ascending'), [], ICON_SIZE_MEDIUM),
+                    Display::getMdiIcon(ActionIcon::UP, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Sort Ascending')),
                     $url.'&'.http_build_query(['order' => 'ASC'])
                 );
             }
@@ -570,7 +563,7 @@ class GlossaryManager
             if (api_is_allowed_to_edit(true, true)) {
                 $content .= Display::noDataView(
                     get_lang('Glossary'),
-                    Display::return_icon('glossary.png', '', [], 64),
+                    Display::getMdiIcon(ObjectIcon::GLOSSARY, 'ch-tool-icon', null, ICON_SIZE_BIG),
                     get_lang('Add glossary'),
                     $url.'&'.http_build_query(['action' => 'addglossary'])
                 );
@@ -815,7 +808,7 @@ class GlossaryManager
     {
         $glossary_id = $row[2];
         $return = '<a href="'.api_get_self().'?action=edit_glossary&glossary_id='.$glossary_id.'&'.api_get_cidreq().'&msg=edit">'.
-            Display::return_icon('edit.png', get_lang('Edit'), '', 22).'</a>';
+            Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')).'</a>';
         $repo = Container::getGlossaryRepository();
         /** @var CGlossary $glossaryData */
         $glossaryData = $repo->find($glossary_id);
@@ -824,7 +817,7 @@ class GlossaryManager
             $return .= '<a
                 href="'.api_get_self().'?action=delete_glossary&glossary_id='.$glossary_id.'&'.api_get_cidreq().'"
                 onclick="return confirmation(\''.$glossaryTerm.'\');">'.
-                Display::return_icon('delete.png', get_lang('Delete'), '', 22).'</a>';
+                Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
             /*
              * if ($glossaryData->getSessionId() == api_get_session_id()) {
             } else {
diff --git a/public/main/inc/lib/grade_model.lib.php b/public/main/inc/lib/grade_model.lib.php
index 1b21b1a686..a8a4d1fe63 100644
--- a/public/main/inc/lib/grade_model.lib.php
+++ b/public/main/inc/lib/grade_model.lib.php
@@ -1,6 +1,8 @@
 <?php
 /* For licensing terms, see /license.txt */
 
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+
 /**
  * Class GradeModel.
  */
@@ -50,9 +52,9 @@ class GradeModel extends Model
         // action links
         echo '<div class="actions" style="margin-bottom:20px">';
         echo '<a href="grade_models.php">'.
-                Display::return_icon('back.png', get_lang('Back'), '', ICON_SIZE_MEDIUM).'</a>';
+                Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')).'</a>';
         echo '<a href="'.api_get_self().'?action=add">'.
-                Display::return_icon('add.png', get_lang('Add'), '', ICON_SIZE_MEDIUM).'</a>';
+                Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add')).'</a>';
         echo '</div>';
         echo Display::grid_html('grade_model');
     }
diff --git a/public/main/inc/lib/link.lib.php b/public/main/inc/lib/link.lib.php
index cab6d6988d..fd67d235a7 100644
--- a/public/main/inc/lib/link.lib.php
+++ b/public/main/inc/lib/link.lib.php
@@ -5,6 +5,9 @@
 use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CourseBundle\Entity\CLink;
 use Chamilo\CourseBundle\Entity\CLinkCategory;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 /**
  * Function library for the links tool.
@@ -881,12 +884,7 @@ class Link extends Model
             $user = api_get_user_entity();
             $i = 1;
             $linksAdded = [];
-            $iconLink = Display::return_icon(
-                'url.png',
-                get_lang('Link'),
-                null,
-                ICON_SIZE_SMALL
-            );
+            $iconLink = Display::getMdiIcon(ActionIcon::LINK, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Link'));
             foreach ($links as $link) {
                 $linkId = $link->getIid();
                 $resourceLink = $link->getFirstResourceLink();
@@ -1079,57 +1077,63 @@ class Link extends Model
         $categoryId = $category->getIid();
         $token = null;
         $tools = '<a href="'.api_get_self().'?'.api_get_cidreq().'&sec_token='.$token.'&action=editcategory&id='.$categoryId.'&category_id='.$categoryId.'" title='.get_lang('Edit').'">'.
-            Display:: return_icon(
-                'edit.png',
-                get_lang('Edit'),
-                [],
-                ICON_SIZE_SMALL
+            Display::getMdiIcon(
+                ActionIcon::EDIT,
+                'ch-tool-icon',
+                null,
+                ICON_SIZE_SMALL,
+                get_lang('Edit')
             ).'</a>';
 
         // DISPLAY MOVE UP COMMAND only if it is not the top link.
         if (0 != $currentCategory) {
             $tools .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&sec_token='.$token.'&action=up&up='.$categoryId.'&category_id='.$categoryId.'" title="'.get_lang('Up').'">'.
-                Display:: return_icon(
-                    'up.png',
-                    get_lang('Up'),
-                    [],
-                    ICON_SIZE_SMALL
+                Display::getMdiIcon(
+                    ActionIcon::UP,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_SMALL,
+                    get_lang('Up')
                 ).'</a>';
         } else {
-            $tools .= Display:: return_icon(
-                'up_na.png',
-                get_lang('Up'),
-                [],
-                ICON_SIZE_SMALL
+            $tools .= Display::getMdiIcon(
+                ActionIcon::UP,
+                'ch-tool-icon-disabled',
+                null,
+                ICON_SIZE_SMALL,
+                get_lang('Up')
             ).'</a>';
         }
 
         // DISPLAY MOVE DOWN COMMAND only if it is not the bottom link.
         if ($currentCategory < $countCategories - 1) {
             $tools .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&sec_token='.$token.'&action=down&down='.$categoryId.'&category_id='.$categoryId.'">'.
-                Display:: return_icon(
-                    'down.png',
-                    get_lang('down'),
-                    [],
-                    ICON_SIZE_SMALL
+                Display::getMdiIcon(
+                    ActionIcon::DOWN,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_SMALL,
+                    get_lang('down')
                 ).'</a>';
         } else {
-            $tools .= Display:: return_icon(
-                'down_na.png',
-                get_lang('down'),
-                [],
-                ICON_SIZE_SMALL
-            ).'</a>';
+            $tools .= Display::getMdiIcon(
+                ActionIcon::DOWN,
+                'ch-tool-icon-disabled',
+                null,
+                ICON_SIZE_SMALL,
+                get_lang('down')
+                ).'</a>';
         }
 
         $tools .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&sec_token='.$token.'&action=deletecategory&id='.$categoryId."&category_id=$categoryId\"
             onclick=\"javascript: if(!confirm('".get_lang('When deleting a category, all links of this category are also deleted.
 Do you really want to delete this category and its links ?')."')) return false;\">".
-            Display:: return_icon(
-                'delete.png',
-                get_lang('Delete'),
-                [],
-                ICON_SIZE_SMALL
+            Display::getMdiIcon(
+                ActionIcon::DELETE,
+                'ch-tool-icon',
+                null,
+                ICON_SIZE_SMALL,
+                get_lang('Delete')
             ).'</a>';
 
         return $tools;
@@ -1365,31 +1369,21 @@ Do you really want to delete this category and its links ?')."')) return false;\
             if (api_is_allowed_to_edit(null, true)) {
                 $actions .= '<a
                     href="'.api_get_self().'?'.api_get_cidreq().'&action=addlink&category_id='.$categoryId.'">'.
-                    Display::return_icon('new_link.png', get_lang('Add a link'), '', ICON_SIZE_MEDIUM).'</a>';
+                    Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add a link')).'</a>';
                 $actions .= '<a
                     href="'.api_get_self().'?'.api_get_cidreq().'&action=addcategory&category_id='.$categoryId.'">'.
-                    Display::return_icon('new_folder.png', get_lang('Add a category'), '', ICON_SIZE_MEDIUM).'</a>';
+                    Display::getMdiIcon(ActionIcon::CREATE_CATEGORY, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add a category')).'</a>';
             }
 
             if (!empty($countCategories)) {
                 $actions .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&action=list&show=none">';
-                $actions .= Display::return_icon(
-                        'forum_listview.png',
-                        get_lang('List View'),
-                        '',
-                        ICON_SIZE_MEDIUM
-                    ).' </a>';
+                $actions .= Display::getMdiIcon(StateIcon::LIST_VIEW, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('List View')).' </a>';
 
                 $actions .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&action=list&show=all">';
-                $actions .= Display::return_icon(
-                        'forum_nestedview.png',
-                        get_lang('Nested View'),
-                        '',
-                        ICON_SIZE_MEDIUM
-                    ).'</a>';
+                $actions .= Display::getMdiIcon(StateIcon::NESTED_VIEW, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Nested View')).'</a>';
             }
             $actions .= Display::url(
-                Display::return_icon('pdf.png', get_lang('Export to PDF'), '', ICON_SIZE_MEDIUM),
+                Display::getMdiIcon(ActionIcon::EXPORT_PDF, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Export to PDF')),
                 api_get_self().'?'.api_get_cidreq().'&action=export'
             );
             $toolbar = Display::toolbarAction('toolbar', [$actions]);
@@ -1430,25 +1424,25 @@ Do you really want to delete this category and its links ?')."')) return false;\
                 $strVisibility = '<a
                     href="link.php?'.api_get_cidreq().'&sec_token='.$token.'&action=invisible&id='.$categoryItemId.'&scope='.TOOL_LINK_CATEGORY.'"
                     title="'.get_lang('Hide').'">'.
-                    Display::return_icon('visible.png', get_lang('Hide'), [], ICON_SIZE_SMALL).'</a>';
+                    Display::getMdiIcon(StateIcon::ACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Hide')).'</a>';
             } elseif (!$isVisible) {
                 $visibilityClass = 'text-muted';
                 $strVisibility = ' <a
                     href="link.php?'.api_get_cidreq().'&sec_token='.$token.'&action=visible&id='.$categoryItemId.'&scope='.TOOL_LINK_CATEGORY.'"
                     title="'.get_lang('Show').'">'.
-                    Display::return_icon('invisible.png', get_lang('Show'), [], ICON_SIZE_SMALL).'</a>';
+                    Display::getMdiIcon(StateIcon::INACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Show')).'</a>';
             }
 
             $header = '';
             if ($showChildren) {
                 $header .= '<a
                     class="'.$visibilityClass.'" href="'.api_get_self().'?'.api_get_cidreq().'&category_id=">';
-                $header .= Display::return_icon('forum_nestedview.png');
+                $header .= Display::getMdiIcon(StateIcon::NESTED_VIEW, 'ch-tool-icon', null, ICON_SIZE_SMALL);
             } else {
                 $header .= '<a
                     class="'.$visibilityClass.'"
                     href="'.api_get_self().'?'.api_get_cidreq().'&category_id='.$categoryItemId.'">';
-                $header .= Display::return_icon('forum_listview.png');
+                $header .= Display::getMdiIcon(StateIcon::LIST_VIEW, 'ch-tool-icon', null, ICON_SIZE_SMALL);
             }
             $header .= Security::remove_XSS($category->getCategoryTitle()).'</a>';
 
@@ -1481,7 +1475,7 @@ Do you really want to delete this category and its links ?')."')) return false;\
         if (empty($content) && api_is_allowed_to_edit()) {
             $content .= Display::noDataView(
                 get_lang('Links'),
-                Display::return_icon('links.png', '', [], 64),
+                Display::getMdiIcon(ObjectIcon::LINK, 'ch-tool-icon', null, ICON_SIZE_BIG),
                 get_lang('Add links'),
                 api_get_self().'?'.api_get_cidreq().'&'.http_build_query(['action' => 'addlink'])
             );
diff --git a/public/main/inc/lib/notebook.lib.php b/public/main/inc/lib/notebook.lib.php
index 7999a1c814..0ffba2bc97 100644
--- a/public/main/inc/lib/notebook.lib.php
+++ b/public/main/inc/lib/notebook.lib.php
@@ -4,6 +4,7 @@
 use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CourseBundle\Entity\CNotebook;
 use ChamiloSession as Session;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * This class provides methods for the notebook management.
@@ -189,21 +190,22 @@ class NotebookManager
         if (!api_is_anonymous()) {
             if (0 == $sessionId || api_is_allowed_to_session_edit(false, true)) {
                 echo '<a href="index.php?'.api_get_cidreq().'&action=addnote">'.
-                    Display::return_icon('new_note.png', get_lang('Add new note in my personal notebook'), '', '32').
+                    Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add new note in my personal notebook')).
                     '</a>';
             }
         }
 
         echo '<a
             href="index.php?'.api_get_cidreq().'&action=changeview&view=creation_date&direction='.$link_sort_direction.'">'.
-            Display::return_icon('notes_order_by_date_new.png', get_lang('Sort by date created'), '', '32').
+            Display::getMdiIcon(ActionIcon::SORT_DATE, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Sort by date created')).
             '</a>';
         echo '<a
             href="index.php?'.api_get_cidreq().'&action=changeview&view=update_date&direction='.$link_sort_direction.'">'.
-            Display::return_icon('notes_order_by_date_mod.png', get_lang('Sort by date last modified'), '', '32').
+            Display::getMdiIcon(ActionIcon::SORT_DATE, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Sort by date last modified')).
             '</a>';
         echo '<a href="index.php?'.api_get_cidreq().'&action=changeview&view=title&direction='.$link_sort_direction.'">'.
-            Display::return_icon('notes_order_by_title.png', get_lang('Sort by title'), '', '32').'</a>';
+            Display::getMdiIcon(ActionIcon::SORT_ALPHA, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Sort by title')).
+            '</a>';
         echo '</div>';
 
         $notebookView = Session::read('notebook_view');
@@ -242,11 +244,11 @@ class NotebookManager
             }
 
             $actions = '<a href="'.api_get_self().'?action=editnote&notebook_id='.$row['notebook_id'].'">'.
-                Display::return_icon('edit.png', get_lang('Edit'), '', ICON_SIZE_SMALL).'</a>';
+                Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')).'</a>';
             $actions .= '<a
                 href="'.api_get_self().'?action=deletenote&notebook_id='.$row['notebook_id'].'"
                 onclick="return confirmation(\''.$row['title'].'\');">'.
-                Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL).'</a>';
+                Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
 
             echo Display::panel(
                 $row['description'],
diff --git a/public/main/inc/lib/plugin.lib.php b/public/main/inc/lib/plugin.lib.php
index cedae0c423..459c182fad 100644
--- a/public/main/inc/lib/plugin.lib.php
+++ b/public/main/inc/lib/plugin.lib.php
@@ -2,6 +2,7 @@
 /* See license terms in /license.txt */
 
 use ChamiloSession as Session;
+use Chamilo\CoreBundle\Component\Utils\ToolIcon;
 
 /**
  * Class AppPlugin.
@@ -708,11 +709,12 @@ class AppPlugin
                         ICON_SIZE_SMALL
                     );
                 } else {
-                    $icon = Display::return_icon(
-                        'plugins.png',
-                        Security::remove_XSS($pluginTitle),
-                        '',
-                        ICON_SIZE_SMALL
+                    $icon = Display::getMdiIcon(
+                        ToolIcon::PLUGIN,
+                        'ch-tool-icon',
+                        null,
+                        ICON_SIZE_SMALL,
+                        Security::remove_XSS($pluginTitle)
                     );
                 }
 
diff --git a/public/main/inc/lib/promotion.lib.php b/public/main/inc/lib/promotion.lib.php
index d42118732f..a0f8f5a454 100644
--- a/public/main/inc/lib/promotion.lib.php
+++ b/public/main/inc/lib/promotion.lib.php
@@ -3,6 +3,8 @@
 /* For licensing terms, see /license.txt */
 
 use Chamilo\CoreBundle\Entity\Promotion as PromotionEntity;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
 
 /**
  * Class Promotion
@@ -163,27 +165,12 @@ class Promotion extends Model
     public function display()
     {
         $actions = '<a href="career_dashboard.php">'.
-            Display::return_icon(
-                'back.png',
-                get_lang('Back'),
-                '',
-                '32'
-            )
+            Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back'))
             .'</a>';
         $actions .= '<a href="'.api_get_self().'?action=add">'.
-            Display::return_icon(
-                'new_promotion.png',
-                get_lang('Add'),
-                '',
-                '32'
-            ).'</a>';
+            Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add')).'</a>';
         $actions .= '<a href="'.api_get_path(WEB_CODE_PATH).'session/session_add.php">'.
-            Display::return_icon(
-                'new_session.png',
-                get_lang('Add a training session'),
-                '',
-                '32'
-            ).'</a>';
+            Display::getMdiIcon(ObjectIcon::SESSION, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add a training session')).'</a>';
 
         echo Display::toolbarAction('promotion_actions', [$actions]);
         echo Display::grid_html('promotions');
diff --git a/public/main/inc/lib/sessionmanager.lib.php b/public/main/inc/lib/sessionmanager.lib.php
index 8028adf6ba..a057f827f0 100644
--- a/public/main/inc/lib/sessionmanager.lib.php
+++ b/public/main/inc/lib/sessionmanager.lib.php
@@ -17,6 +17,9 @@ use Chamilo\CourseBundle\Entity\CSurvey;
 use ExtraField as ExtraFieldModel;
 use Monolog\Logger;
 use Symfony\Component\HttpFoundation\File\UploadedFile;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 /**
  * This is the session library for Chamilo
@@ -697,18 +700,8 @@ class SessionManager
                 return $sessions[0]['total_rows'];
             }
 
-            $activeIcon = Display::return_icon(
-                'accept.png',
-                get_lang('Active'),
-                [],
-                ICON_SIZE_SMALL
-            );
-            $inactiveIcon = Display::return_icon(
-                'error.png',
-                get_lang('Inactive'),
-                [],
-                ICON_SIZE_SMALL
-            );
+            $activeIcon = Display::getMdiIcon(StateIcon::ACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Active'));
+            $inactiveIcon = Display::getMdiIcon(StateIcon::INACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Inactive'));
 
             foreach ($sessions as $session) {
                 $session_id = $session['id'];
@@ -735,7 +728,7 @@ class SessionManager
                     // ofaj
                     $session['teachers'] = '';
                     if (!empty($teachers)) {
-                        $session['teachers'] = Display::return_icon('teacher.png', addslashes($teachers));
+                        $session['teachers'] = Display::getMdiIcon(ObjectIcon::TEACHER, 'ch-tool-icon', null, ICON_SIZE_SMALL, addslashes($teachers));
                     }
                 }
                 $url = api_get_path(WEB_CODE_PATH).'session/resume_session.php?id_session='.$session['id'];
@@ -896,8 +889,8 @@ class SessionManager
             }
         }
 
-        $activeIcon = Display::return_icon('accept.png', get_lang('active'));
-        $inactiveIcon = Display::return_icon('error.png', get_lang('inactive'));
+        $activeIcon = Display::getMdiIcon(StateIcon::ACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('active'));
+        $inactiveIcon = Display::getMdiIcon(StateIcon::INACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('inactive'));
 
         foreach ($sessions as $session) {
             if ($showCountUsers) {
@@ -9122,19 +9115,9 @@ class SessionManager
 
         $result = Database::query($query);
 
-        $acceptIcon = Display::return_icon(
-            'accept.png',
-            get_lang('Active'),
-            [],
-            ICON_SIZE_SMALL
-        );
+        $acceptIcon = Display::getMdiIcon(StateIcon::ACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Active'));
 
-        $errorIcon = Display::return_icon(
-            'error.png',
-            get_lang('Inactive'),
-            [],
-            ICON_SIZE_SMALL
-        );
+        $errorIcon = Display::getMdiIcon(StateIcon::INACTIVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Inactive'));
 
         $formatted_sessions = [];
         if (Database::num_rows($result)) {
diff --git a/public/main/inc/lib/social.lib.php b/public/main/inc/lib/social.lib.php
index b07eb9706f..511bde8b2b 100644
--- a/public/main/inc/lib/social.lib.php
+++ b/public/main/inc/lib/social.lib.php
@@ -11,6 +11,9 @@ use Chamilo\CourseBundle\Entity\CForumThread;
 use ChamiloSession as Session;
 use Laminas\Feed\Reader\Entry\Rss;
 use Laminas\Feed\Reader\Reader;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 /**
  * Class SocialManager.
@@ -455,7 +458,7 @@ class SocialManager extends UserManager
                     $iconRss = '';
                     if (!empty($feed)) {
                         $iconRss = Display::url(
-                            Display::return_icon('social_rss.png', '', [], 22),
+                            Display::getMdiIcon('rss', 'ch-tool-icon', null, ICON_SIZE_SMALL),
                             Security::remove_XSS($feed['rssfeeds']),
                             ['target' => '_blank']
                         );
@@ -593,12 +596,12 @@ class SocialManager extends UserManager
             $lastname = $user_info['lastname'];
             $firstname = $user_info['firstname'];
             $completeName = $firstname.', '.$lastname;
-            $user_rol = 1 == $user_info['status'] ? Display::return_icon('teacher.png', get_lang('Trainer'), null, ICON_SIZE_TINY) : Display::return_icon('user.png', get_lang('Learner'), null, ICON_SIZE_TINY);
+            $user_rol = 1 == $user_info['status'] ? Display::getMdiIcon(ObjectIcon::TEACHER, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Trainer')) : Display::getMdiIcon(ObjectIcon::USER, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Learner'));
             $status_icon_chat = null;
             if (isset($user_info['user_is_online_in_chat']) && 1 == $user_info['user_is_online_in_chat']) {
-                $status_icon_chat = Display::return_icon('online.png', get_lang('Online'));
+                $status_icon_chat = Display::getMdiIcon(StateIcon::ONLINE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Online'));
             } else {
-                $status_icon_chat = Display::return_icon('offline.png', get_lang('Offline'));
+                $status_icon_chat = Display::getMdiIcon(StateIcon::OFFLINE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Offline'));
             }
 
             $userPicture = $user_info['avatar'];
@@ -1161,10 +1164,10 @@ class SocialManager extends UserManager
                 $name_user = api_get_person_name($friend['firstName'], $friend['lastName']);
                 $user_info_friend = api_get_user_info($friend['friend_user_id'], true);
 
-                $statusIcon = Display::return_icon('statusoffline.png', get_lang('Offline'));
+                $statusIcon = Display::getMdiIcon(StateIcon::OFFLINE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Offline'));
                 $status = 0;
                 if (!empty($user_info_friend['user_is_online_in_chat'])) {
-                    $statusIcon = Display::return_icon('statusonline.png', get_lang('Online'));
+                    $statusIcon = Display::getMdiIcon(StateIcon::ONLINE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Online'));
                     $status = 1;
                 }
 
@@ -2012,7 +2015,7 @@ class SocialManager extends UserManager
 
         if ($canEdit) {
             $htmlDelete = Display::url(
-                Display::getMdiIcon('delete'),
+                Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL),
                 'javascript:void(0)',
                 [
                     'id' => 'message_'.$message['id'],
diff --git a/public/main/inc/lib/statistics.lib.php b/public/main/inc/lib/statistics.lib.php
index 94dd37efcd..d888959e99 100644
--- a/public/main/inc/lib/statistics.lib.php
+++ b/public/main/inc/lib/statistics.lib.php
@@ -3,6 +3,7 @@
 
 use Chamilo\CoreBundle\Component\Utils\ChamiloApi;
 use Chamilo\CoreBundle\Entity\UserRelUser;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * This class provides some functions for statistics.
@@ -1345,7 +1346,7 @@ class Statistics
 
             if (!empty($result)) {
                 $actions = Display::url(
-                    Display::return_icon('excel.png', get_lang('ExportToXls'), [], ICON_SIZE_MEDIUM),
+                    Display::getMdiIcon(ActionIcon::EXPORT_SPREADSHEET, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('ExportToXls')),
                     api_get_self().'?'.http_build_query(
                         [
                             'report' => 'logins_by_date',
diff --git a/public/main/inc/lib/template.lib.php b/public/main/inc/lib/template.lib.php
index fa7adf025c..3c767abb62 100644
--- a/public/main/inc/lib/template.lib.php
+++ b/public/main/inc/lib/template.lib.php
@@ -8,6 +8,7 @@ use Chamilo\CoreBundle\Entity\User;
 use Chamilo\CoreBundle\Framework\Container;
 use Symfony\Component\Filesystem\Exception\FileNotFoundException;
 use Symfony\Component\HttpFoundation\Response;
+use Chamilo\CoreBundle\Component\Utils\ToolIcon;
 
 /**
  * Class Template.
@@ -183,7 +184,7 @@ class Template
                 $help = Security::remove_XSS($help);
                 $content = '<div class="help">';
                 $content .= Display::url(
-                    Display::return_icon('help.png', get_lang('Help'), null, ICON_SIZE_LARGE),
+                    Display::getMdiIcon(ToolIcon::HELP, 'ch-tool-icon', null, ICON_SIZE_LARGE, get_lang('Help')),
                     api_get_path(WEB_CODE_PATH).'help/help.php?open='.$help,
                     [
                         'class' => 'ajax',
@@ -998,12 +999,7 @@ class Template
     {
         //@todo move this in the template
         $rightFloatMenu = '';
-        $iconBug = Display::return_icon(
-            'bug.png',
-            get_lang('Report a bug'),
-            [],
-            ICON_SIZE_LARGE
-        );
+        $iconBug = Display::getMdiIcon(ToolIcon::BUG_REPORT, 'ch-tool-icon', null, ICON_SIZE_LARGE, get_lang('Report a bug'));
         if ('true' === api_get_setting('show_link_bug_notification') && $this->user_is_logged_in) {
             $rightFloatMenu = '<div class="report">
 		        <a href="https://github.com/chamilo/chamilo-lms/wiki/How-to-report-issues" target="_blank">
@@ -1017,12 +1013,7 @@ class Template
         ) {
             // by default is project_id = 1
             $defaultProjectId = 1;
-            $iconTicket = Display::return_icon(
-                'help.png',
-                get_lang('Ticket'),
-                [],
-                ICON_SIZE_LARGE
-            );
+            $iconTicket = Display::getMdiIcon(ToolIcon::HELP, 'ch-tool-icon', null, ICON_SIZE_LARGE, get_lang('Ticket'));
             $courseInfo = api_get_course_info();
             $courseParams = '';
             if (!empty($courseInfo)) {
diff --git a/public/main/inc/lib/thematic.lib.php b/public/main/inc/lib/thematic.lib.php
index 680b499306..5035c90755 100644
--- a/public/main/inc/lib/thematic.lib.php
+++ b/public/main/inc/lib/thematic.lib.php
@@ -9,6 +9,7 @@ use Chamilo\CourseBundle\Entity\CAttendance;
 use Chamilo\CourseBundle\Entity\CThematic;
 use Chamilo\CourseBundle\Entity\CThematicAdvance;
 use Chamilo\CourseBundle\Entity\CThematicPlan;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * Provides functions for thematic option inside attendance tool.
@@ -516,11 +517,11 @@ class Thematic
                 $actions = '';
                 $actions .= '<a
                         href="index.php?'.api_get_cidreq().'&action=thematic_advance_edit&thematic_id='.$thematic_id.'&thematic_advance_id='.$thematic_advance[0].'">'.
-                        Display::return_icon('edit.png', get_lang('Edit'), '', 22).'</a>';
+                        Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')).'</a>';
                 $actions .= '<a
                     onclick="javascript:if(!confirm(\''.get_lang('Are you sure you want to delete').'\')) return false;"
                     href="index.php?'.api_get_cidreq().'&action=thematic_advance_delete&thematic_id='.$thematic_id.'&thematic_advance_id='.$thematic_advance[0].'">'.
-                        Display::return_icon('delete.png', get_lang('Delete'), '', 22).'</a></center>';
+                        Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a></center>';
                 $data[] = [$i, $thematic_advance[1], $thematic_advance[2], $thematic_advance[3], $actions];
                 $i++;
                 // }
diff --git a/public/main/inc/lib/tracking.lib.php b/public/main/inc/lib/tracking.lib.php
index a5dd3e3002..9c68113554 100644
--- a/public/main/inc/lib/tracking.lib.php
+++ b/public/main/inc/lib/tracking.lib.php
@@ -16,6 +16,8 @@ use CpChart\Cache as pCache;
 use CpChart\Data as pData;
 use CpChart\Image as pImage;
 use ExtraField as ExtraFieldModel;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 /**
  *  Class Tracking.
@@ -218,13 +220,25 @@ class Tracking
         $extend_all = 0;
         if (!empty($extendedAll)) {
             $extend_all_link = Display::url(
-                Display::return_icon('view_less_stats.gif', get_lang('Hide all attempts')),
+                Display::getMdiIcon(
+                    ActionIcon::VIEW_LESS,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_SMALL,
+                    get_lang('Hide all attempts')
+                ),
                 api_get_self().'?action=stats'.$url_suffix
             );
             $extend_all = 1;
         } else {
             $extend_all_link = Display::url(
-                Display::return_icon('view_more_stats.gif', get_lang('Show all attempts')),
+                Display::getMdiIcon(
+                    ActionIcon::VIEW_MORE,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_SMALL,
+                    get_lang('Show all attempts')
+                ),
                 api_get_self().'?action=stats&extend_all=1'.$url_suffix
             );
         }
@@ -405,7 +419,12 @@ class Tracking
                     $extend_link = '';
                     if (!empty($inter_num)) {
                         $extend_link = Display::url(
-                            Display::getMdiIcon('eye', 'ch-tool-icon', null, 22, get_lang('Hide attempt view')
+                            Display::getMdiIcon(
+                                ActionIcon::VISIBLE,
+                                'ch-tool-icon',
+                                null,
+                                ICON_SIZE_SMALL,
+                                get_lang('Hide attempt view')
                             ),
                             api_get_self().'?action=stats&fold_id='.$my_item_id.$url_suffix
                         );
@@ -476,27 +495,51 @@ class Tracking
                                 // The extend button for this attempt has been clicked.
                                 $extend_this_attempt = 1;
                                 $extend_attempt_link = Display::url(
-                                    Display::getMdiIcon('eye', 'ch-tool-icon', null, 22, get_lang('Hide attempt view')),
+                                    Display::getMdiIcon(
+                                        ActionIcon::VISIBLE,
+                                        'ch-tool-icon',
+                                        null,
+                                        ICON_SIZE_SMALL,
+                                        get_lang('Hide attempt view')
+                                    ),
                                     api_get_self().'?action=stats&extend_id='.$my_item_id.'&fold_attempt_id='.$row['iv_id'].$url_suffix
                                 );
                                 if ($accessToPdfExport) {
                                     $extend_attempt_link .= '&nbsp;'.
                                         Display::url(
-                                            Display::getMdiIcon('file-pdf-box', 'ch-tool-icon', null, 22, get_lang('Export to PDF')),
+                                            Display::getMdiIcon(
+                                                ActionIcon::EXPORT_PDF,
+                                                'ch-tool-icon',
+                                                null,
+                                                ICON_SIZE_SMALL,
+                                                get_lang('Export to PDF')
+                                            ),
                                             api_get_self().'?action=export_stats&extend_id='.$my_item_id.'&extend_attempt_id='.$row['iv_id'].$url_suffix,
                                             ['class' => 'export']
                                         );
                                 }
                             } else { // Same case if fold_attempt_id is set, so not implemented explicitly.
-                                // The extend button for this attempt has not been clicked.
+                                // The "extend" button for this attempt has not been clicked.
                                 $extend_attempt_link = Display::url(
-                                    Display::getMdiIcon('eye-off', 'ch-tool-icon', null, 22, get_lang('Extend attempt view')),
+                                    Display::getMdiIcon(
+                                        ActionIcon::INVISIBLE,
+                                        'ch-tool-icon',
+                                        null,
+                                        ICON_SIZE_SMALL,
+                                        get_lang('Extend attempt view')
+                                    ),
                                     api_get_self().'?action=stats&extend_id='.$my_item_id.'&extend_attempt_id='.$row['iv_id'].$url_suffix
                                 );
                                 if ($accessToPdfExport) {
                                     $extend_attempt_link .= '&nbsp;'.
                                         Display::url(
-                                            Display::getMdiIcon('file-pdf-box', 'ch-tool-icon', null, 22, get_lang('Export to PDF')),
+                                            Display::getMdiIcon(
+                                                ActionIcon::EXPORT_PDF,
+                                                'ch-tool-icon',
+                                                null,
+                                                ICON_SIZE_SMALL,
+                                                get_lang('Export to PDF')
+                                            ),
                                             api_get_self().'?action=export_stats&extend_id='.$my_item_id.'&extend_attempt_id='.$row['iv_id'].$url_suffix,
                                             ['class' => 'export']
                                         );
@@ -551,7 +594,12 @@ class Tracking
 
                         if ('dir' !== $row['item_type']) {
                             if (!$is_allowed_to_edit && $result_disabled_ext_all) {
-                                $view_score = Display::getMdiIcon('eye-off', 'ch-tool-icon', null, 22, get_lang('Results hidden by the exercise setting')
+                                $view_score = Display::getMdiIcon(
+                                    ActionIcon::INVISIBLE,
+                                    'ch-tool-icon',
+                                    null,
+                                    ICON_SIZE_SMALL,
+                                    get_lang('Results hidden by the exercise setting')
                                 );
                             } else {
                                 switch ($row['item_type']) {
@@ -712,14 +760,26 @@ class Tracking
                             // The extend button for this attempt has been clicked.
                             $extend_this_attempt = 1;
                             $extend_attempt_link = Display::url(
-                                Display::getMdiIcon('eye', 'ch-tool-icon', null, 22, get_lang('Hide attempt view')),
+                                Display::getMdiIcon(
+                                    ActionIcon::VISIBLE,
+                                    'ch-tool-icon',
+                                    null,
+                                    ICON_SIZE_SMALL,
+                                    get_lang('Hide attempt view')
+                                ),
                                 api_get_self().'?action=stats&extend_id='.$my_item_id.'&fold_attempt_id='.$row['iv_id'].$url_suffix
                             );
                         } else {
                             // Same case if fold_attempt_id is set, so not implemented explicitly.
                             // The "Extend" button for this attempt has not been clicked.
                             $extend_attempt_link = Display::url(
-                                Display::getMdiIcon('eye-off', 'ch-tool-icon', null, 22, get_lang('Extend attempt view')),
+                                Display::getMdiIcon(
+                                    ActionIcon::INVISIBLE,
+                                    'ch-tool-icon',
+                                    null,
+                                    ICON_SIZE_SMALL,
+                                    get_lang('Extend attempt view')
+                                ),
                                 api_get_self().'?action=stats&extend_id='.$my_item_id.'&extend_attempt_id='.$row['iv_id'].$url_suffix
                             );
                         }
@@ -733,7 +793,13 @@ class Tracking
                     $extend_link = '';
                     if ($inter_num > 1) {
                         $extend_link = Display::url(
-                            Display::getMdiIcon('eye-off', 'ch-tool-icon', null, 22, get_lang('Extend attempt view')),
+                            Display::getMdiIcon(
+                                ActionIcon::INVISIBLE,
+                                'ch-tool-icon',
+                                null,
+                                ICON_SIZE_SMALL,
+                                get_lang('Extend attempt view')
+                            ),
                             api_get_self().'?action=stats&extend_id='.$my_item_id.'&extend_attempt_id='.$row['iv_id'].$url_suffix
                         );
                     }
@@ -906,8 +972,11 @@ class Tracking
                                 ) {
                                     $showRowspan = true;
                                     $correct_test_link = Display::url(
-                                        Display::return_icon(
-                                            'view_less_stats.gif',
+                                        Display::getMdiIcon(
+                                            ActionIcon::VIEW_LESS,
+                                            'ch-tool-icon',
+                                            null,
+                                            ICON_SIZE_SMALL,
                                             get_lang('Hide all attempts')
                                         ),
                                         api_get_self().'?action=stats'.$my_url_suffix.'&sid='.$sessionId.'&lp_item_id='.$my_id.'#'.$linkId,
@@ -915,8 +984,11 @@ class Tracking
                                     );
                                 } else {
                                     $correct_test_link = Display::url(
-                                        Display::return_icon(
-                                            'view_more_stats.gif',
+                                        Display::getMdiIcon(
+                                            ActionIcon::VIEW_MORE,
+                                            'ch-tool-icon',
+                                            null,
+                                            ICON_SIZE_SMALL,
                                             get_lang(
                                                 'Show all attemptsByExercise'
                                             )
@@ -954,7 +1026,12 @@ class Tracking
                             $scoreItem = null;
                             if ('quiz' === $row['item_type']) {
                                 if (!$is_allowed_to_edit && $result_disabled_ext_all) {
-                                    $scoreItem .= Display::getMdiIcon('eye-off', 'ch-tool-icon', null, 22, get_lang('Results hidden by the exercise setting')
+                                    $scoreItem .= Display::getMdiIcon(
+                                        ActionIcon::INVISIBLE,
+                                        'ch-tool-icon',
+                                        null,
+                                        ICON_SIZE_SMALL,
+                                        get_lang('Results hidden by the exercise setting')
                                     );
                                 } else {
                                     $scoreItem .= ExerciseLib::show_score($score, $maxscore, false);
@@ -1096,11 +1173,12 @@ class Tracking
                                             $time_attemp = api_format_time($row_attempts['exe_duration'], 'js');
                                         }
                                         if (!$is_allowed_to_edit && $result_disabled_ext_all) {
-                                            $view_score = Display::return_icon(
-                                                'invisible.png',
-                                                get_lang(
-                                                    'Results hidden by the exercise setting'
-                                                )
+                                            $view_score = Display::getMdiIcon(
+                                                ActionIcon::INVISIBLE,
+                                                'ch-tool-icon',
+                                                null,
+                                                ICON_SIZE_SMALL,
+                                                get_lang('Results hidden by the exercise setting')
                                             );
                                         } else {
                                             // Show only float when need it
@@ -1241,7 +1319,13 @@ class Tracking
         $total_time = str_replace('NaN', '00'.$h.'00\'00"', $total_time);
 
         if (!$is_allowed_to_edit && $result_disabled_ext_all) {
-            $final_score = Display::getMdiIcon('eye-off', 'ch-tool-icon', null, 22, get_lang('Results hidden by the exercise setting'));
+            $final_score = Display::getMdiIcon(
+                ActionIcon::INVISIBLE,
+                'ch-tool-icon',
+                null,
+                ICON_SIZE_SMALL,
+                get_lang('Results hidden by the exercise setting')
+            );
             $finalScoreToCsv = get_lang('Results hidden by the exercise setting');
         } else {
             if (is_numeric($total_score)) {
@@ -2080,7 +2164,12 @@ class Tracking
                                 $url = api_get_path(WEB_CODE_PATH).
                                     'announcements/announcements.php?action=add&remind_inactive='.$student_id.'&cid='.$courseInfo['real_id'];
                                 $icon = '<a href="'.$url.'" title="'.get_lang('Remind inactive user').'">
-                                  '.Display::getMdiIcon('alert').'
+                                  '.Display::getMdiIcon(
+                                      StateIcon::WARNING,
+                                      'ch-tool-icon',
+                                      null,
+                                      ICON_SIZE_SMALL
+                                    ).'
                                  </a>';
                             }
 
@@ -4645,7 +4734,7 @@ class Tracking
                         'book-open-page-variant',
                         'ch-tool-icon',
                         null,
-                        22,
+                        ICON_SIZE_SMALL,
                         get_lang('My courses')
                     ).' '.get_lang('My courses')
                 );
@@ -4775,11 +4864,23 @@ class Tracking
                         empty($_GET['session_id'])
                     ) {
                         $detailsLink .= '<a href="#course_session_header">';
-                        $detailsLink .= Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 22, get_lang('Details'));
+                        $detailsLink .= Display::getMdiIcon(
+                            'fast-forward-outline',
+                            'ch-tool-icon',
+                            null,
+                            ICON_SIZE_SMALL,
+                            get_lang('Details')
+                        );
                         $detailsLink .= '</a>';
                     } else {
                         $detailsLink .= '<a href="'.api_get_self().'?course='.$courseCode.$extra_params.'#course_session_header">';
-                        $detailsLink .= Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 22, get_lang('Details'));
+                        $detailsLink .= Display::getMdiIcon(
+                            'fast-forward-outline',
+                            'ch-tool-icon',
+                            null,
+                            ICON_SIZE_SMALL,
+                            get_lang('Details')
+                        );
                         $detailsLink .= '</a>';
                     }
 
@@ -4916,7 +5017,13 @@ class Tracking
                 );
             }
 
-            $sessionIcon = Display::getMdiIcon('google-classroom', 'ch-tool-icon', null, 22, get_lang('Course sessions'));
+            $sessionIcon = Display::getMdiIcon(
+                'google-classroom',
+                'ch-tool-icon',
+                null,
+                ICON_SIZE_SMALL,
+                get_lang('Course sessions')
+            );
 
             $anchor = Display::url('', '', ['name' => 'course_session_header']);
             $html .= $anchor.Display::page_subheader(
@@ -5012,13 +5119,24 @@ class Tracking
 
                 if (isset($_GET['session_id']) && $my_session_id == $_GET['session_id']) {
                     $icon = Display::url(
-                        Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 22, get_lang('Details')
+                        Display::getMdiIcon(
+                            'fast-forward-outline',
+                            'ch-tool-icon',
+                            null,
+                            ICON_SIZE_SMALL,
+                            get_lang('Details')
                         ),
                         api_get_self().'?session_id='.$my_session_id.'#course_session_list'
                     );
                 } else {
                     $icon = Display::url(
-                        Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 22, get_lang('Details')),
+                        Display::getMdiIcon(
+                            'fast-forward-outline',
+                            'ch-tool-icon',
+                            null,
+                            ICON_SIZE_SMALL,
+                            get_lang('Details')
+                        ),
                         api_get_self().'?session_id='.$my_session_id.'#course_session_list'
                     );
                 }
@@ -5073,10 +5191,12 @@ class Tracking
                     ],
                     'score' => [
                         get_lang('Score').
-                        Display::return_icon(
-                            'info3.gif',
-                            get_lang('Average of tests in Learning Paths'),
-                            ['align' => 'absmiddle', 'hspace' => '3px']
+                        Display::getMdiIcon(
+                            ActionIcon::INFORMATION,
+                            'ch-tool-icon',
+                            null,
+                            ICON_SIZE_SMALL,
+                            get_lang('Average of tests in Learning Paths')
                         ),
                     ],
                     'best_score' => [
@@ -5236,14 +5356,14 @@ class Tracking
                         $_GET['session_id'] == $session_id_from_get
                     ) {
                         $details = Display::url(
-                            Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 22, get_lang('Details')),
+                            Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Details')),
                         '#course_session_data'
                         );
                     } else {
                         $url = api_get_self().
                             '?course='.$course_code.'&session_id='.$session_id_from_get.$extra_params.'#course_session_data';
                         $details = Display::url(
-                            Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 22, get_lang('Details')
+                            Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Details')
                             ),
                             $url
                         );
@@ -5335,11 +5455,13 @@ class Tracking
             <th>'.get_lang('Ranking').'</th>
             <th>'.get_lang('Best result in course').'</th>
             <th>'.get_lang('Statistics').' '
-                .Display::return_icon(
-                    'info3.gif',
-                    get_lang('In case of multiple attempts, only shows the best result of each learner'),
-                    ['align' => 'absmiddle', 'hspace' => '3px']
-                ).
+                .Display::getMdiIcon(
+                    ActionIcon::INFORMATION,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_SMALL,
+                    get_lang('In case of multiple attempts')
+                    ).
             '</th>
             </tr>
             </thead>
@@ -7550,7 +7672,13 @@ class Tracking
                 get_lang('BestAttempt'),
                 get_lang('Ranking'),
                 get_lang('BestResultInCourse'),
-                get_lang('Statistics').Display::return_icon('info3.gif', get_lang('OnlyBestResultsPerStudent')),
+                get_lang('Statistics').Display::getMdiIcon(
+                    ActionIcon::INFORMATION,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_SMALL,
+                    get_lang('OnlyBestResultsPerStudent')
+                ),
             ]
         );
 
@@ -8784,8 +8912,13 @@ class TrackingCourseLog
             $url = $urlBase.'&student='.$user['user_id'];
 
             $user['link'] = '<center><a href="'.$url.'">
-                            '.Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 32, get_lang('Details')).'
-                             </a></center>';
+                            '.Display::getMdiIcon(
+                                'fast-forward-outline',
+                                'ch-tool-icon',
+                                null,
+                                ICON_SIZE_MEDIUM,
+                                get_lang('Details')
+                ).'</a></center>';
 
             // store columns in array $users
             $user_row = [];
@@ -8998,8 +9131,13 @@ class TrackingCourseLog
                 <center>
                  <a
                     href="../my_space/myStudents.php?student='.$user['user_id'].'&details=true&cid='.$courseId.'&origin=tracking_course&sid='.$sessionId.'">
-                    '.Display::getMdiIcon('fast-forward-outline', 'ch-tool-icon', null, 22, get_lang('Details')).'
-                 </a>
+                    '.Display::getMdiIcon(
+                        'fast-forward-outline',
+                        'ch-tool-icon',
+                        null,
+                        ICON_SIZE_SMALL,
+                        get_lang('Details')
+                ).'</a>
                 </center>';
 
             // store columns in array $users
@@ -9030,37 +9168,37 @@ class TrackingCourseLog
     public static function actionsLeft($current, $sessionId = 0, $addWrapper = true)
     {
         $usersLink = Display::url(
-            Display::getMdiIcon('account', 'ch-tool-icon', null, 32, get_lang('Report on learners')),
+            Display::getMdiIcon('account', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Report on learners')),
             'courseLog.php?'.api_get_cidreq(true, false)
         );
 
         $groupsLink = Display::url(
-            Display::getMdiIcon('account-group', 'ch-tool-icon', null, 32, get_lang('Group reporting')),
+            Display::getMdiIcon('account-group', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Group reporting')),
             'course_log_groups.php?'.api_get_cidreq()
         );
         $resourcesLink = '';
         /*$resourcesLink = Display::url(
-            Display::getMdiIcon('chart-box', 'ch-tool-icon', null, 32, get_lang('Report on resource')),
+            Display::getMdiIcon('chart-box', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Report on resource')),
             'course_log_resources.php?'.api_get_cidreq(true, false)
         );*/
 
         $courseLink = Display::url(
-            Display::getMdiIcon('book-open-page-variant	', 'ch-tool-icon', null, 32, get_lang('Course report')),
+            Display::getMdiIcon('book-open-page-variant	', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Course report')),
             'course_log_tools.php?'.api_get_cidreq(true, false)
         );
 
         $examLink = Display::url(
-            Display::getMdiIcon('chart-box', 'ch-tool-icon', null, 32, get_lang('Exam tracking')),
+            Display::getMdiIcon('chart-box', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Exam tracking')),
             api_get_path(WEB_CODE_PATH).'tracking/exams.php?'.api_get_cidreq()
         );
 
         $eventsLink = Display::url(
-            Display::getMdiIcon('security', 'ch-tool-icon', null, 32, get_lang('Audit report')),
+            Display::getMdiIcon('security', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Audit report')),
             api_get_path(WEB_CODE_PATH).'tracking/course_log_events.php?'.api_get_cidreq()
         );
 
         $lpLink = Display::url(
-            Display::getMdiIcon('map-marker-path', 'ch-tool-icon', null, 32, get_lang('CourseLPsGenericStats')),
+            Display::getMdiIcon('map-marker-path', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('CourseLPsGenericStats')),
             api_get_path(WEB_CODE_PATH).'tracking/lp_report.php?'.api_get_cidreq()
         );
 
@@ -9073,7 +9211,7 @@ class TrackingCourseLog
             $checkExport = $attendance->getAttendanceLogin($startDate, $endDate);
             if (false !== $checkExport) {
                 $attendanceLink = Display::url(
-                    Display::getMdiIcon('av-timer', 'ch-tool-icon', null, 32, get_lang('Logins')),
+                    Display::getMdiIcon('av-timer', 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Logins')),
                     api_get_path(WEB_CODE_PATH).'attendance/index.php?'.api_get_cidreq().'&action=calendar_logins'
                 );
             }
@@ -9082,51 +9220,51 @@ class TrackingCourseLog
         switch ($current) {
             case 'users':
                 $usersLink = Display::url(
-                        Display::getMdiIcon('account', 'ch-tool-icon-disabled', null, 32, get_lang('Report on learners')),
+                        Display::getMdiIcon('account', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Report on learners')),
                     '#'
                 );
                 break;
             case 'groups':
                 $groupsLink = Display::url(
-                    Display::getMdiIcon('account-group', 'ch-tool-icon-disabled', null, 32, get_lang('Group reporting')),
+                    Display::getMdiIcon('account-group', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Group reporting')),
                     '#'
                 );
                 break;
             case 'courses':
                 $courseLink = Display::url(
-                    Display::getMdiIcon('book-open-page-variant', 'ch-tool-icon-disabled', null, 32, get_lang('Course report')),
+                    Display::getMdiIcon('book-open-page-variant', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Course report')),
                     '#'
                 );
                 break;
             case 'resources':
                 $resourcesLink = Display::url(
-                    Display::getMdiIcon('package-variant-closed', 'ch-tool-icon-disabled', null, 32, get_lang('Report on resource')),
+                    Display::getMdiIcon('package-variant-closed', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Report on resource')),
                     '#'
                 );
                 break;
             case 'exams':
                 $examLink = Display::url(
-                    Display::getMdiIcon('order-bool-ascending-variant', 'ch-tool-icon-disabled', null, 32, get_lang('Exam tracking')),
+                    Display::getMdiIcon('order-bool-ascending-variant', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Exam tracking')),
                     '#'
                 );
                 break;
             case 'logs':
                 $eventsLink = Display::url(
-                    Display::getMdiIcon('security', 'ch-tool-icon-disabled', null, 32, get_lang('Audit report')),
+                    Display::getMdiIcon('security', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Audit report')),
                     '#'
                 );
                 break;
             case 'attendance':
                 if (!empty($sessionId)) {
                     $attendanceLink = Display::url(
-                        Display::getMdiIcon('av-timer', 'ch-tool-icon-disabled', null, 32, get_lang('Logins')),
+                        Display::getMdiIcon('av-timer', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Logins')),
                         '#'
                     );
                 }
                 break;
             case 'lp':
                 $lpLink = Display::url(
-                    Display::getMdiIcon('map-marker-path', 'ch-tool-icon-disabled', null, 32, get_lang('CourseLPsGenericStats')),
+                    Display::getMdiIcon('map-marker-path', 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('CourseLPsGenericStats')),
                     '#'
                 );
                 break;
diff --git a/public/main/inc/lib/usergroup.lib.php b/public/main/inc/lib/usergroup.lib.php
index fbaf364371..195cddceba 100644
--- a/public/main/inc/lib/usergroup.lib.php
+++ b/public/main/inc/lib/usergroup.lib.php
@@ -6,6 +6,7 @@ use Chamilo\CoreBundle\Entity\ResourceFile;
 use Chamilo\CoreBundle\Entity\Usergroup;
 use Chamilo\CoreBundle\Framework\Container;
 use Symfony\Component\HttpFoundation\File\UploadedFile;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * Class UserGroup.
@@ -331,24 +332,25 @@ class UserGroupModel extends Model
         $actions = '';
         if (api_is_platform_admin()) {
             $actions .= '<a href="../admin/index.php">'.
-                Display::return_icon(
-                    'back.png',
-                    get_lang('Back to').' '.get_lang('Administration'),
-                    '',
-                    ICON_SIZE_MEDIUM
+                Display::getMdiIcon(
+                    ActionIcon::BACK,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_MEDIUM,
+                    get_lang('Back to').' '.get_lang('Administration')
                 ).
                 '</a>';
         }
 
         $actions .= '<a href="'.api_get_self().'?action=add">'.
-            Display::return_icon('new_class.png', get_lang('Add classes'), '', ICON_SIZE_MEDIUM).
+            Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add classes')).
             '</a>';
         $actions .= Display::url(
-            Display::return_icon('import_csv.png', get_lang('Import'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ActionIcon::IMPORT_ARCHIVE, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Import')),
             'usergroup_import.php'
         );
         $actions .= Display::url(
-            Display::return_icon('export_csv.png', get_lang('Export'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ActionIcon::EXPORT_CSV, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Export')),
             'usergroup_export.php'
         );
         $html .= Display::toolbarAction('toolbar', [$actions]);
@@ -367,11 +369,23 @@ class UserGroupModel extends Model
         $courseInfo = api_get_course_info();
         if (empty($courseInfo)) {
             echo '<a href="../admin/usergroups.php">'.
-                Display::return_icon('back.png', get_lang('Back to').' '.get_lang('Administration'), '', '32').
+                Display::getMdiIcon(
+                    ActionIcon::BACK,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_MEDIUM,
+                    get_lang('Back to').' '.get_lang('Administration')
+                ).
                 '</a>';
         } else {
             echo Display::url(
-                Display::return_icon('back.png', get_lang('Back to').' '.get_lang('Administration'), '', '32'),
+                Display::getMdiIcon(
+                    ActionIcon::BACK,
+                    'ch-tool-icon',
+                    null,
+                    ICON_SIZE_MEDIUM,
+                    get_lang('Back to').' '.get_lang('Administration')
+                ),
                 api_get_path(WEB_CODE_PATH).'user/class.php?'.api_get_cidreq()
             );
         }
@@ -2547,7 +2561,7 @@ class UserGroupModel extends Model
             case GROUP_USER_PERMISSION_ADMIN:
                 $relation_group_title = get_lang('I am an admin');
                 $links .= '<li class="'.('group_edit' == $show ? 'active' : '').'"><a href="group_edit.php?id='.$group_id.'">'.
-                            Display::return_icon('group_edit.png', get_lang('Edit this group')).get_lang('Edit this group').'</a></li>';
+                            Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Edit this group')).get_lang('Edit this group').'</a></li>';
                 $links .= '<li class="'.('member_list' == $show ? 'active' : '').'"><a href="group_waiting_list.php?id='.$group_id.'">'.
                             Display::return_icon('waiting_list.png', get_lang('Waiting list')).get_lang('Waiting list').'</a></li>';
                 $links .= '<li class="'.('invite_friends' == $show ? 'active' : '').'"><a href="group_invitation.php?id='.$group_id.'">'.
diff --git a/public/main/inc/lib/webservices/Rest.php b/public/main/inc/lib/webservices/Rest.php
index f3bd1d6a1a..3b722650dc 100644
--- a/public/main/inc/lib/webservices/Rest.php
+++ b/public/main/inc/lib/webservices/Rest.php
@@ -11,6 +11,7 @@ use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CourseBundle\Entity\CLpCategory;
 use Chamilo\CourseBundle\Entity\CNotebook;
 use Chamilo\CourseBundle\Repository\CNotebookRepository;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
 
 /**
  * Class RestApi.
@@ -2018,7 +2019,7 @@ class Rest extends WebService
             "modules" => [],
         ];
 
-        $quizIcon = Display::return_icon('quiz.png', '', [], ICON_SIZE_SMALL, false, true);
+        $quizIcon = Display::getMdiIcon(ObjectIcon::TEST, 'ch-tool-icon', null, ICON_SIZE_SMALL);
 
         $json['modules'] = array_map(
             function (array $exercise) use ($quizIcon) {
diff --git a/public/main/inc/lib/zombie/zombie_report.class.php b/public/main/inc/lib/zombie/zombie_report.class.php
index 915af27cf0..4d2cb237a7 100644
--- a/public/main/inc/lib/zombie/zombie_report.class.php
+++ b/public/main/inc/lib/zombie/zombie_report.class.php
@@ -1,5 +1,9 @@
 <?php
 
+/* For licensing terms, see /license.txt */
+
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
+
 /**
  * Description of zombie_report.
  *
@@ -267,16 +271,14 @@ class ZombieReport implements Countable
     {
         $active = '1' == $active;
         if ($active) {
-            $image = 'accept';
+            $image = StateIcon::COMPLETE;
             $text = get_lang('Yes');
         } else {
-            $image = 'error';
+            $image = StateIcon::INCOMPLETE;
             $text = get_lang('No');
         }
 
-        $result = Display::return_icon($image.'.png', $text);
-
-        return $result;
+        return Display::getMdiIcon($image, 'ch-tool-icon', null, ICON_SIZE_SMALL, $text);
     }
 
     public function format_status($status)
diff --git a/public/main/notebook/index.php b/public/main/notebook/index.php
index fcf0eba6b4..900f53ed80 100644
--- a/public/main/notebook/index.php
+++ b/public/main/notebook/index.php
@@ -2,6 +2,7 @@
 /* For licensing terms, see /license.txt */
 
 use ChamiloSession as Session;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 /**
  * @author Christian Fasanando, initial version
@@ -118,7 +119,7 @@ if ('addnote' === $action) {
             'add_glossary',
             [
                 Display::url(
-                    Display::return_icon('back.png', get_lang('Back'), [], ICON_SIZE_MEDIUM),
+                    Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')),
                     api_get_self().'?'.api_get_cidreq()
                 ),
             ]
@@ -181,7 +182,7 @@ if ('addnote' === $action) {
             'add_glossary',
             [
                 Display::url(
-                    Display::return_icon('back.png', get_lang('Back'), [], ICON_SIZE_MEDIUM),
+                    Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')),
                     api_get_self().'?'.api_get_cidreq()
                 ),
             ]
diff --git a/public/main/portfolio/add_category.php b/public/main/portfolio/add_category.php
index c9dbdffa8d..a69fa8401c 100644
--- a/public/main/portfolio/add_category.php
+++ b/public/main/portfolio/add_category.php
@@ -2,6 +2,7 @@
 /* For licensing terms, see /license.txt */
 
 use Chamilo\CoreBundle\Entity\PortfolioCategory;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 $form = new FormValidator('add_category', 'post', "$baseUrl&action=add_category");
 if ('true' === api_get_setting('editor.save_titles_as_html')) {
@@ -40,7 +41,7 @@ $interbreadcrumb[] = [
 ];
 
 $actions[] = Display::url(
-    Display::return_icon('back.png', get_lang('Back'), [], ICON_SIZE_MEDIUM),
+    Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')),
     $baseUrl
 );
 $content = $form->returnForm();
diff --git a/public/main/portfolio/add_item.php b/public/main/portfolio/add_item.php
index 799c29e03c..c94a3e9c41 100644
--- a/public/main/portfolio/add_item.php
+++ b/public/main/portfolio/add_item.php
@@ -2,6 +2,7 @@
 /* For licensing terms, see /license.txt */
 
 use Chamilo\CoreBundle\Entity\Portfolio;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
 
 $categories = $em
     ->getRepository('ChamiloCoreBundle:PortfolioCategory')
@@ -58,7 +59,7 @@ $interbreadcrumb[] = [
 ];
 
 $actions[] = Display::url(
-    Display::return_icon('back.png', get_lang('Back'), [], ICON_SIZE_MEDIUM),
+    Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')),
     $baseUrl
 );
 $content = $form->returnForm();
diff --git a/public/main/portfolio/edit_category.php b/public/main/portfolio/edit_category.php
index 39e1d239fa..3d27df2185 100644
--- a/public/main/portfolio/edit_category.php
+++ b/public/main/portfolio/edit_category.php
@@ -1,6 +1,8 @@
 <?php
 /* For licensing terms, see /license.txt */
 
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+
 $form = new FormValidator('edit_category', 'post', $baseUrl."action=edit_category&id={$category->getId()}");
 if ('true' === api_get_setting('editor.save_titles_as_html')) {
     $form->addHtmlEditor('title', get_lang('Title'), true, false, ['ToolbarSet' => 'TitleAsHtml']);
@@ -39,7 +41,7 @@ $interbreadcrumb[] = [
     'url' => $baseUrl,
 ];
 $actions[] = Display::url(
-    Display::return_icon('back.png', get_lang('Back'), [], ICON_SIZE_MEDIUM),
+    Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')),
     $baseUrl
 );
 $content = $form->returnForm();
diff --git a/public/main/portfolio/edit_item.php b/public/main/portfolio/edit_item.php
index 991e0f442a..3bd950c491 100644
--- a/public/main/portfolio/edit_item.php
+++ b/public/main/portfolio/edit_item.php
@@ -1,6 +1,8 @@
 <?php
 /* For licensing terms, see /license.txt */
 
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+
 $categories = $em
     ->getRepository('ChamiloCoreBundle:PortfolioCategory')
     ->findBy([
@@ -52,7 +54,7 @@ $interbreadcrumb[] = [
     'url' => $baseUrl,
 ];
 $actions[] = Display::url(
-    Display::return_icon('back.png', get_lang('Back'), [], ICON_SIZE_MEDIUM),
+    Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back')),
     $baseUrl
 );
 $content = $form->returnForm();
diff --git a/public/main/portfolio/list.php b/public/main/portfolio/list.php
index 578c7d59db..0ea63e12a6 100644
--- a/public/main/portfolio/list.php
+++ b/public/main/portfolio/list.php
@@ -1,23 +1,27 @@
 <?php
 /* For licensing terms, see /license.txt */
 
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\ToolIcon;
+
 if ($currentUserId == $user->getId()) {
     if ($allowEdit) {
         $actions[] = Display::url(
-            Display::return_icon('add.png', get_lang('Add'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add')),
             $baseUrl.'action=add_item'
         );
         $actions[] = Display::url(
-            Display::return_icon('folder.png', get_lang('Add category'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ObjectIcon::FOLDER, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Add category')),
             $baseUrl.'action=add_category'
         );
         $actions[] = Display::url(
-            Display::return_icon('shared_setting.png', get_lang('Preview'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ToolIcon::SETTINGS, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Preview')),
             $baseUrl.'preview=&user='.$user->getId()
         );
     } else {
         $actions[] = Display::url(
-            Display::return_icon('shared_setting_na.png', get_lang('Preview'), [], ICON_SIZE_MEDIUM),
+            Display::getMdiIcon(ToolIcon::SETTINGS, 'ch-tool-icon-disabled', null, ICON_SIZE_MEDIUM, get_lang('Preview')),
             $baseUrl
         );
     }
diff --git a/public/main/work/work.lib.php b/public/main/work/work.lib.php
index a7b1c6274e..239fc7440a 100644
--- a/public/main/work/work.lib.php
+++ b/public/main/work/work.lib.php
@@ -11,6 +11,9 @@ use Chamilo\CourseBundle\Entity\CStudentPublication;
 use Chamilo\CourseBundle\Entity\CStudentPublicationAssignment;
 use Chamilo\CourseBundle\Entity\CStudentPublicationComment;
 use ChamiloSession as Session;
+use Chamilo\CoreBundle\Component\Utils\ActionIcon;
+use Chamilo\CoreBundle\Component\Utils\ObjectIcon;
+use Chamilo\CoreBundle\Component\Utils\StateIcon;
 
 /**
  *  @author Thomas, Hugues, Christophe - original version
@@ -42,7 +45,7 @@ function displayWorkActionLinks($id, $action, $isTutor)
 
     if (!empty($id)) {
         $output .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&id='.$my_back_id.'">'.
-            Display::return_icon('back.png', get_lang('Back to Assignments list'), '', ICON_SIZE_MEDIUM).
+            Display::getMdiIcon(ActionIcon::BACK, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Back to Assignments list')).
             '</a>';
     }
 
@@ -52,24 +55,14 @@ function displayWorkActionLinks($id, $action, $isTutor)
         // Create dir
         if (empty($id)) {
             $output .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&action=create_dir">';
-            $output .= Display::return_icon(
-                'new_work.png',
-                get_lang('Create assignment'),
-                '',
-                ICON_SIZE_MEDIUM
-            );
+            $output .= Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('Create assignment'));
             $output .= '</a>';
         }
     }
 
     if (api_is_allowed_to_edit(null, true) && 'learnpath' !== $origin && 'list' === $action) {
         $output .= '<a id="open-view-list" href="#">'.
-            Display::return_icon(
-                'listwork.png',
-                get_lang('View students'),
-                '',
-                ICON_SIZE_MEDIUM
-            ).
+            Display::getMdiIcon(StateIcon::LIST_VIEW, 'ch-tool-icon', null, ICON_SIZE_MEDIUM, get_lang('View students')).
             '</a>';
     }
 
@@ -1270,7 +1263,7 @@ function getWorkListStudent(
     $studentPublications = $qb->getQuery()->getResult();
     $urlOthers = api_get_path(WEB_CODE_PATH).'work/work_list_others.php?'.api_get_cidreq().'&id=';
     //while ($work = Database::fetch_array($result, 'ASSOC')) {
-    $icon = Display::return_icon('work.png');
+    $icon = Display::getMdiIcon(ObjectIcon::ASSIGNMENT, 'ch-tool-icon', null, ICON_SIZE_SMALL);
 
     /** @var CStudentPublication $studentPublication */
     foreach ($studentPublications as $studentPublication) {
@@ -1325,7 +1318,7 @@ function getWorkListStudent(
 
         $work['title'] = Display::url($title, $url.'&id='.$workId);
         $work['others'] = Display::url(
-            Display::return_icon('group.png', get_lang('Others')),
+            Display::getMdiIcon(ObjectIcon::GROUP, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Others')),
             $urlOthers.$workId
         );
         $works[] = $work;
@@ -1485,7 +1478,7 @@ function getAllWorkListStudent(
             continue;
         }*/
 
-        $work['type'] = Display::return_icon('work.png');
+        $work['type'] = Display::getMdiIcon(ObjectIcon::ASSIGNMENT, 'ch-tool-icon', null, ICON_SIZE_SMALL);
         $work['expires_on'] = empty($work['expires_on']) ? null : api_get_local_time($work['expires_on']);
 
         if (empty($work['title'])) {
@@ -1629,7 +1622,7 @@ function getWorkListTeacher(
         $blockEdition = ('true' === api_get_setting('work.block_student_publication_edition'));
 
         //while ($work = Database::fetch_array($result, 'ASSOC')) {
-        $icon = Display::return_icon('work.png');
+        $icon = Display::getMdiIcon(ObjectIcon::ASSIGNMENT, 'ch-tool-icon', null, ICON_SIZE_SMALL);
         /** @var CStudentPublication $studentPublication */
         foreach ($studentPublications as $studentPublication) {
             $workId = $studentPublication->getIid();
@@ -1662,19 +1655,19 @@ function getWorkListTeacher(
             //$visibility = api_get_item_visibility($courseInfo, 'work', $workId, $session_id);
             $isVisible = $studentPublication->isVisible($course, $session);
             if ($isVisible) {
-                $icon = 'visible.png';
+                $icon = ActionIcon::VISIBLE;
                 $text = get_lang('Visible');
                 $action = 'invisible';
                 $class = '';
             } else {
-                $icon = 'invisible.png';
+                $icon = ActionIcon::INVISIBLE;
                 $text = get_lang('invisible');
                 $action = 'visible';
                 $class = 'muted';
             }
 
             $visibilityLink = Display::url(
-                Display::return_icon($icon, $text, [], ICON_SIZE_SMALL),
+                Display::getMdiIcon($icon, 'ch-tool-icon', null, ICON_SIZE_SMALL, $text),
                 api_get_path(WEB_CODE_PATH).'work/work.php?id='.$workId.'&action='.$action.'&'.api_get_cidreq()
             );
 
@@ -1687,34 +1680,24 @@ function getWorkListTeacher(
                 $editLink = '';
             } else {
                 $editLink = Display::url(
-                    Display::return_icon('edit.png', get_lang('Edit'), [], ICON_SIZE_SMALL),
+                    Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')),
                     api_get_path(WEB_CODE_PATH).'work/edit_work.php?id='.$workId.'&'.api_get_cidreq()
                 );
             }
 
             $correctionLink = '&nbsp;'.Display::url(
-                Display::return_icon('upload_package.png', get_lang('Upload corrections'), '', ICON_SIZE_SMALL),
+                Display::getMdiIcon(ActionIcon::UPLOAD, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Upload corrections')),
                 api_get_path(WEB_CODE_PATH).'work/upload_corrections.php?'.api_get_cidreq().'&id='.$workId
             ).'&nbsp;';
 
             if ($countUniqueAttempts > 0) {
                 $downloadLink = Display::url(
-                    Display::return_icon(
-                        'save_pack.png',
-                        get_lang('Save'),
-                        [],
-                        ICON_SIZE_SMALL
-                    ),
+                    Display::getMdiIcon(ActionIcon::SAVE_FORM, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Save')),
                     api_get_path(WEB_CODE_PATH).'work/downloadfolder.inc.php?id='.$workId.'&'.api_get_cidreq()
                 );
             } else {
                 $downloadLink = Display::url(
-                    Display::return_icon(
-                        'save_pack_na.png',
-                        get_lang('Save'),
-                        [],
-                        ICON_SIZE_SMALL
-                    ),
+                    Display::getMdiIcon(ActionIcon::SAVE_FORM, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Save')),
                     '#'
                 );
             }
@@ -1870,16 +1853,11 @@ function get_work_user_list_from_documents(
     $urlView = api_get_path(WEB_CODE_PATH).'work/view.php?'.api_get_cidreq();
     $urlDownload = api_get_path(WEB_CODE_PATH).'work/download.php?'.api_get_cidreq();
 
-    $editIcon = Display::return_icon('edit.png', get_lang('Edit'));
-    $addIcon = Display::return_icon('add.png', get_lang('Add'));
-    $deleteIcon = Display::return_icon('delete.png', get_lang('Delete'));
-    $viewIcon = Display::return_icon('default.png', get_lang('View'));
-    $saveIcon = Display::return_icon(
-        'save.png',
-        get_lang('Save'),
-        [],
-        ICON_SIZE_SMALL
-    );
+    $editIcon = Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit'));
+    $addIcon = Display::getMdiIcon(ActionIcon::ADD, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Add'));
+    $deleteIcon = Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete'));
+    $viewIcon = Display::getMdiIcon(ObjectIcon::DEFAULT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('View'));
+    $saveIcon = Display::getMdiIcon(ActionIcon::SAVE_FORM, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Save'));
     $allowEdition = 1 == api_get_course_setting('student_delete_own_publication');
 
     $workList = [];
@@ -2137,39 +2115,19 @@ function get_work_user_list(
         $loadingText = addslashes(get_lang('Loading'));
         $uploadedText = addslashes(get_lang('Uploaded.'));
         $failsUploadText = addslashes(get_lang('No file was uploaded..'));
-        $failsUploadIcon = Display::return_icon(
-            'closed-circle.png',
-            '',
-            [],
+        $failsUploadIcon = Display::getMdiIcon(
+            StateIcon::INCOMPLETE,
+            'ch-tool-icon',
+            null,
             ICON_SIZE_TINY
         );
-        $saveIcon = Display::return_icon(
-            'save.png',
-            get_lang('Save'),
-            [],
-            ICON_SIZE_SMALL
-        );
+        $saveIcon = Display::getMdiIcon(ActionIcon::SAVE_FORM, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Save'));
 
-        $correctionIcon = Display::return_icon(
-            'check-circle.png',
-            get_lang('Correction'),
-            null,
-            ICON_SIZE_SMALL
-        );
+        $correctionIcon = Display::getMdiIcon(ActionIcon::ACCEPT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Correction'));
 
-        $correctionIconSmall = Display::return_icon(
-            'check-circle.png',
-            get_lang('Correction'),
-            null,
-            ICON_SIZE_TINY
-        );
+        $correctionIconSmall = Display::getMdiIcon(ActionIcon::ACCEPT, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Correction'));
 
-        $rateIcon = Display::return_icon(
-            'rate_work.png',
-            get_lang('Correct and rate'),
-            [],
-            ICON_SIZE_SMALL
-        );
+        $rateIcon = Display::getMdiIcon(ActionIcon::GRADE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Correct and rate'));
 
         $blockEdition = ('true' === api_get_setting('work.block_student_publication_edition'));
         $blockScoreEdition = ('true' === api_get_setting('work.block_student_publication_score_edition'));
@@ -2327,7 +2285,7 @@ function get_work_user_list(
                         $action .= '<a
                             href="'.$url.'work_list_all.php?'.api_get_cidreq().'&id='.$workId.'&action=export_to_doc&item_id='.$item_id.'"
                             title="'.get_lang('Export to .doc').'" >'.
-                            Display::return_icon('export_doc.png', get_lang('Export to .doc'), [], ICON_SIZE_SMALL).'</a> ';
+                            Display::getMdiIcon(ActionIcon::EXPORT_DOC, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Export to .doc')).'</a> ';
                     }
 
                     $alreadyUploaded = '';
@@ -2346,7 +2304,7 @@ function get_work_user_list(
                         >
                         <div id="progress_'.$item_id.'" class="text-center button-load">
                             '.addslashes(get_lang('Click or drop one file here')).'
-                            '.Display::return_icon('upload_file.png', get_lang('Correction'), [], ICON_SIZE_TINY).'
+                            '.Display::getMdiIcon(ActionIcon::UPLOAD, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Correction')).'
                             '.$alreadyUploaded.'
                         </div>
                         <input id="file_'.$item_id.'" type="file" name="file" class="" multiple>
@@ -2389,14 +2347,9 @@ function get_work_user_list(
 
                     if ($locked) {
                         if ($qualification_exists) {
-                            $action .= Display::return_icon(
-                                'edit_na.png',
-                                get_lang('Correct and rate'),
-                                [],
-                                ICON_SIZE_SMALL
-                            );
+                            $action .= Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Correct and rate'));
                         } else {
-                            $action .= Display::return_icon('edit_na.png', get_lang('Comment'), [], ICON_SIZE_SMALL);
+                            $action .= Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Comment'));
                         }
                     } else {
                         if ($blockEdition && !api_is_platform_admin()) {
@@ -2406,12 +2359,12 @@ function get_work_user_list(
                                 $editLink = '<a
                                     href="'.$url.'edit.php?'.api_get_cidreq().'&item_id='.$item_id.'&id='.$workId.'"
                                     title="'.get_lang('Edit').'"  >'.
-                                    Display::return_icon('edit.png', get_lang('Edit'), [], ICON_SIZE_SMALL).'</a>';
+                                    Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')).'</a>';
                             } else {
                                 $editLink = '<a
                                     href="'.$url.'edit.php?'.api_get_cidreq().'&item_id='.$item_id.'&id='.$workId.'"
                                     title="'.get_lang('Edit').'">'.
-                                    Display::return_icon('edit.png', get_lang('Edit'), [], ICON_SIZE_SMALL).'</a>';
+                                    Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit')).'</a>';
                             }
                         }
                         $action .= $editLink;
@@ -2419,17 +2372,12 @@ function get_work_user_list(
 
                     if ($assignment->getContainsFile()) {
                         if ($locked) {
-                            $action .= Display::return_icon(
-                                'move_na.png',
-                                get_lang('Move'),
-                                [],
-                                ICON_SIZE_SMALL
-                            );
+                            $action .= Display::getMdiIcon(ActionIcon::MOVE, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Move'));
                         } else {
                             $action .= '<a
                                 href="'.$url.'work.php?'.api_get_cidreq().'&action=move&item_id='.$item_id.'&id='.$workId.'"
                                 title="'.get_lang('Move').'">'.
-                                Display::return_icon('move.png', get_lang('Move'), [], ICON_SIZE_SMALL).'</a>';
+                                Display::getMdiIcon(ActionIcon::MOVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Move')).'</a>';
                         }
                     }
 
@@ -2437,30 +2385,30 @@ function get_work_user_list(
                         $action .= '<a
                             href="'.$url.'work_list_all.php?'.api_get_cidreq().'&id='.$workId.'&action=make_invisible&item_id='.$item_id.'"
                             title="'.get_lang('invisible').'" >'.
-                            Display::return_icon('visible.png', get_lang('invisible'), [], ICON_SIZE_SMALL).
+                            Display::getMdiIcon(ActionIcon::INVISIBLE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('invisible')).
                             '</a>';
                     } else {
                         $action .= '<a
                             href="'.$url.'work_list_all.php?'.api_get_cidreq().'&id='.$workId.'&action=make_visible&item_id='.$item_id.'"
                             title="'.get_lang('Visible').'" >'.
-                            Display::return_icon('invisible.png', get_lang('Visible'), [], ICON_SIZE_SMALL).
+                            Display::getMdiIcon(ActionIcon::VISIBLE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Visible')).
                             '</a> ';
                     }
 
                     if ($locked) {
-                        $action .= Display::return_icon('delete_na.png', get_lang('Delete'), '', ICON_SIZE_SMALL);
+                        $action .= Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Delete'));
                     } else {
                         $action .= '<a
                             href="'.$url.'work_list_all.php?'.api_get_cidreq().'&id='.$workId.'&action=delete&item_id='.$item_id.'"
                             onclick="javascript:if(!confirm('."'".addslashes(api_htmlentities(get_lang('Please confirm your choice'), ENT_QUOTES))."'".')) return false;"
                             title="'.get_lang('Delete').'" >'.
-                            Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL).'</a>';
+                            Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
                     }
                 } elseif ($is_author && (empty($qualificatorId) || 0 == $qualificatorId)) {
                     $action .= '<a
                             href="'.$url.'view.php?'.api_get_cidreq().'&id='.$item_id.'"
                             title="'.get_lang('View').'">'.
-                        Display::return_icon('default.png', get_lang('View'), [], ICON_SIZE_SMALL).
+                        Display::getMdiIcon(ObjectIcon::DEFAULT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('View')).
                         '</a>';
 
                     if (1 == $studentDeleteOwnPublication) {
@@ -2468,20 +2416,20 @@ function get_work_user_list(
                             $action .= '<a
                                 href="'.$url.'edit.php?'.api_get_cidreq().'&item_id='.$item_id.'&id='.$workId.'"
                                 title="'.get_lang('Edit').'">'.
-                                Display::return_icon('edit.png', get_lang('Comment'), [], ICON_SIZE_SMALL).
+                                Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Comment')).
                                 '</a>';
                         }
                         $action .= ' <a
                             href="'.$url.'work_list.php?'.api_get_cidreq().'&action=delete&item_id='.$item_id.'&id='.$workId.'"
                             onclick="javascript:if(!confirm('."'".addslashes(api_htmlentities(get_lang('Please confirm your choice'), ENT_QUOTES))."'".')) return false;"
                             title="'.get_lang('Delete').'"  >'.
-                            Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL).'</a>';
+                            Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
                     }
                 } else {
                     $action .= '<a
                         href="'.$url.'view.php?'.api_get_cidreq().'&id='.$item_id.'"
                         title="'.get_lang('View').'">'.
-                        Display::return_icon('default.png', get_lang('View'), [], ICON_SIZE_SMALL).
+                        Display::getMdiIcon(ObjectIcon::DEFAULT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('View')).
                         '</a>';
                 }
 
@@ -2668,39 +2616,19 @@ function getAllWork(
     $loadingText = addslashes(get_lang('Loading'));
     $uploadedText = addslashes(get_lang('Uploaded'));
     $failsUploadText = addslashes(get_lang('UplNoFileUploaded'));
-    $failsUploadIcon = Display::return_icon(
-        'closed-circle.png',
-        '',
-        [],
+    $failsUploadIcon = Display::getMdiIcon(
+        StateIcon::INCOMPLETE,
+        'ch-tool-icon',
+        null,
         ICON_SIZE_TINY
     );
-    $saveIcon = Display::return_icon(
-        'save.png',
-        get_lang('Save'),
-        [],
-        ICON_SIZE_SMALL
-    );
+    $saveIcon = Display::getMdiIcon(ActionIcon::SAVE_FORM, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Save'));
 
-    $correctionIcon = Display::return_icon(
-        'check-circle.png',
-        get_lang('Correction'),
-        null,
-        ICON_SIZE_SMALL
-    );
+    $correctionIcon = Display::getMdiIcon(ActionIcon::ACCEPT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Correction'));
 
-    $correctionIconSmall = Display::return_icon(
-        'check-circle.png',
-        get_lang('Correction'),
-        null,
-        ICON_SIZE_TINY
-    );
+    $correctionIconSmall = Display::getMdiIcon(ActionIcon::ACCEPT, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Correction'));
 
-    $rateIcon = Display::return_icon(
-        'rate_work.png',
-        get_lang('CorrectAndRate'),
-        [],
-        ICON_SIZE_SMALL
-    );
+    $rateIcon = Display::getMdiIcon(ActionIcon::GRADE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('CorrectAndRate'));
     $parentList = [];
     $blockEdition = ('true' === api_get_setting('work.block_student_publication_edition'));
     $blockScoreEdition = ('true' === api_get_setting('work.block_student_publication_score_edition'));
@@ -2805,7 +2733,7 @@ function getAllWork(
                     $feedback .= ' ';
                 }
                 $feedback .= Display::url(
-                    $count.' '.Display::getMdiIcon('comment-multiple-outline'),
+                    $count.' '.Display::getMdiIcon('comment-multiple-outline', 'ch-tool-icon', null, ICON_SIZE_SMALL),
                     $url.'view.php?'.$cidReq.'&id='.$item_id
                 );
             }
@@ -2862,7 +2790,7 @@ function getAllWork(
                     $action .= '<a
                         href="'.$url.'work_list_all.php?'.$cidReq.'&id='.$workId.'&action=export_to_doc&item_id='.$item_id.'"
                         title="'.get_lang('ExportToDoc').'" >'.
-                        Display::return_icon('export_doc.png', get_lang('ExportToDoc'), [], ICON_SIZE_SMALL).'</a> ';
+                        Display::getMdiIcon(ActionIcon::EXPORT_DOC, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('ExportToDoc')).'</a> ';
                 }
 
                 $alreadyUploaded = '';
@@ -2880,7 +2808,7 @@ function getAllWork(
                     >
                     <div id="progress_'.$item_id.'" class="text-center button-load">
                         '.addslashes(get_lang('ClickOrDropOneFileHere')).'
-                        '.Display::return_icon('upload_file.png', get_lang('Correction'), [], ICON_SIZE_TINY).'
+                        '.Display::getMdiIcon(ActionIcon::UPLOAD, 'ch-tool-icon', null, ICON_SIZE_TINY, get_lang('Correction')).'
                         '.$alreadyUploaded.'
                     </div>
                     <input id="file_'.$item_id.'" type="file" name="file" class="" multiple>
@@ -2923,20 +2851,15 @@ function getAllWork(
 
                 if ($locked) {
                     if ($qualification_exists) {
-                        $action .= Display::return_icon(
-                            'edit_na.png',
-                            get_lang('CorrectAndRate'),
-                            [],
-                            ICON_SIZE_SMALL
-                        );
+                        $action .= Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('CorrectAndRate'));
                     } else {
-                        $action .= Display::return_icon('edit_na.png', get_lang('Comment'), [], ICON_SIZE_SMALL);
+                        $action .= Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Comment'));
                     }
                 } else {
                     if ($blockEdition && !api_is_platform_admin()) {
                         $editLink = '';
                     } else {
-                        $editIcon = Display::return_icon('edit.png', get_lang('Edit'), [], ICON_SIZE_SMALL);
+                        $editIcon = Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Edit'));
                         if ($qualification_exists) {
                             $editLink = '<a
                                 href="'.$url.'edit.php?'.$cidReq.'&item_id='.$item_id.'&id='.$work['parent_id'].'"
@@ -2955,46 +2878,41 @@ function getAllWork(
 
                 /*if ($work['contains_file']) {
                     if ($locked) {
-                        $action .= Display::return_icon(
-                            'move_na.png',
-                            get_lang('Move'),
-                            [],
-                            ICON_SIZE_SMALL
-                        );
+                        $action .= Display::getMdiIcon(ActionIcon::MOVE, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Move'));
                     } else {
                         $action .= '<a href="'.$url.'work.php?'.$cidReq.'&action=move&item_id='.$item_id.'&id='.$work['parent_id'].'" title="'.get_lang('Move').'">'.
-                            Display::return_icon('move.png', get_lang('Move'), [], ICON_SIZE_SMALL).'</a>';
+                            Display::getMdiIcon(ActionIcon::MOVE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Move')).'</a>';
                     }
                 }*/
 
                 /*if ($work['accepted'] == '1') {
                     $action .= '<a href="'.$url.'work_list_all.php?'.$cidReq.'&id='.$workId.'&action=make_invisible&item_id='.$item_id.'" title="'.get_lang('Invisible').'" >'.
-                        Display::return_icon('visible.png', get_lang('Invisible'), [], ICON_SIZE_SMALL).'</a>';
+                        Display::getMdiIcon(ActionIcon::INVISIBLE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Invisible')).'</a>';
                 } else {
                     $action .= '<a href="'.$url.'work_list_all.php?'.$cidReq.'&id='.$workId.'&action=make_visible&item_id='.$item_id.'" title="'.get_lang('Visible').'" >'.
-                        Display::return_icon('invisible.png', get_lang('Visible'), [], ICON_SIZE_SMALL).'</a> ';
+                        Display::getMdiIcon(ActionIcon::VISIBLE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Visible')).'</a> ';
                 }*/
                 /*if ($locked) {
-                    $action .= Display::return_icon('delete_na.png', get_lang('Delete'), '', ICON_SIZE_SMALL);
+                    $action .= Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon-disabled', null, ICON_SIZE_SMALL, get_lang('Delete'));
                 } else {
                     $action .= '<a href="'.$url.'work_list_all.php?'.$cidReq.'&id='.$workId.'&action=delete&item_id='.$item_id.'" onclick="javascript:if(!confirm('."'".addslashes(api_htmlentities(get_lang('ConfirmYourChoice'), ENT_QUOTES))."'".')) return false;" title="'.get_lang('Delete').'" >'.
-                        Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL).'</a>';
+                        Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
                 }*/
             } elseif ($is_author && (empty($work['qualificator_id']) || 0 == $work['qualificator_id'])) {
                 $action .= '<a href="'.$url.'view.php?'.$cidReq.'&id='.$item_id.'" title="'.get_lang('View').'">'.
-                    Display::return_icon('default.png', get_lang('View'), [], ICON_SIZE_SMALL).'</a>';
+                    Display::getMdiIcon(ObjectIcon::DEFAULT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('View')).'</a>';
 
                 if (1 == api_get_course_setting('student_delete_own_publication')) {
                     if (api_is_allowed_to_session_edit(false, true)) {
                         $action .= '<a href="'.$url.'edit.php?'.$cidReq.'&item_id='.$item_id.'&id='.$work['parent_id'].'" title="'.get_lang('Modify').'">'.
-                            Display::return_icon('edit.png', get_lang('Comment'), [], ICON_SIZE_SMALL).'</a>';
+                            Display::getMdiIcon(ActionIcon::EDIT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Comment')).'</a>';
                     }
                     $action .= ' <a href="'.$url.'work_list.php?'.$cidReq.'&action=delete&item_id='.$item_id.'&id='.$work['parent_id'].'" onclick="javascript:if(!confirm('."'".addslashes(api_htmlentities(get_lang('ConfirmYourChoice'), ENT_QUOTES))."'".')) return false;" title="'.get_lang('Delete').'"  >'.
-                        Display::return_icon('delete.png', get_lang('Delete'), '', ICON_SIZE_SMALL).'</a>';
+                        Display::getMdiIcon(ActionIcon::DELETE, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('Delete')).'</a>';
                 }
             } else {
                 $action .= '<a href="'.$url.'view.php?'.$cidReq.'&id='.$item_id.'" title="'.get_lang('View').'">'.
-                    Display::return_icon('default.png', get_lang('View'), [], ICON_SIZE_SMALL).'</a>';
+                    Display::getMdiIcon(ObjectIcon::DEFAULT, 'ch-tool-icon', null, ICON_SIZE_SMALL, get_lang('View')).'</a>';
             }
 
             // Status.