From 992eddb87cd0f86ced6c720718683052fbd2f91f Mon Sep 17 00:00:00 2001
From: Angel Fernando Quiroz Campos <angelfqc.18@gmail.com>
Date: Fri, 22 Oct 2021 02:37:25 -0500
Subject: [PATCH] Exercise: Allow reset answers in annotation - refs BT#18831

---
 main/inc/lib/exercise.lib.php                 | 23 +++++++++-----
 .../javascript/annotation/js/annotation.js    | 30 +++++++++++++++++--
 2 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/main/inc/lib/exercise.lib.php b/main/inc/lib/exercise.lib.php
index 732bf2ce23..41c564656c 100644
--- a/main/inc/lib/exercise.lib.php
+++ b/main/inc/lib/exercise.lib.php
@@ -1703,14 +1703,6 @@ HOTSPOT;
                             <div class="col-sm-8 col-md-9">
                                 <div id="annotation-canvas-'.$questionId.'" class="annotation-canvas center-block">
                                 </div>
-                                <script>
-                                    AnnotationQuestion({
-                                        questionId: '.$questionId.',
-                                        exerciseId: '.$exe_id.',
-                                        relPath: \''.$relPath.'\',
-                                        courseId: '.$course_id.',
-                                    });
-                                </script>
                             </div>
                             <div class="col-sm-4 col-md-3">
                                 <div class="well well-sm" id="annotation-toolbar-'.$questionId.'">
@@ -1731,11 +1723,26 @@ HOTSPOT;
                                                 <span class="fa fa-font fa-fw" aria-hidden="true"></span>
                                             </label>
                                         </div>
+                                        <div class="btn-group">
+                                            <button type="button" class="btn btn-default btn-small"
+                                                title="'.get_lang('ClearAnswers').'"
+                                                id="btn-reset-'.$questionId.'">
+                                                <span class="fa fa-times-rectangle fa-fw" aria-hidden="true"></span>
+                                            </button>
+                                        </div>
                                     </div>
                                     <ul class="list-unstyled"></ul>
                                 </div>
                             </div>
                         </div>
+                        <script>
+                            AnnotationQuestion({
+                                questionId: '.$questionId.',
+                                exerciseId: '.$exe_id.',
+                                relPath: \''.$relPath.'\',
+                                courseId: '.$course_id.',
+                            });
+                        </script>
                     </div>
                 ';
             }
diff --git a/main/inc/lib/javascript/annotation/js/annotation.js b/main/inc/lib/javascript/annotation/js/annotation.js
index 67ecf852cc..fda5f39fa2 100644
--- a/main/inc/lib/javascript/annotation/js/annotation.js
+++ b/main/inc/lib/javascript/annotation/js/annotation.js
@@ -157,6 +157,7 @@
         this.models = [];
         this.length = 0;
         this.addEvent = null;
+        this.resetEvent = null;
     };
     ElementsCollection.prototype.add = function (pathModel) {
         pathModel.id = ++this.length;
@@ -170,9 +171,19 @@
     ElementsCollection.prototype.get = function (index) {
         return this.models[index];
     };
+    ElementsCollection.prototype.reset = function () {
+        if (this.resetEvent) {
+            this.resetEvent();
+        }
+
+        this.models = [];
+    }
     ElementsCollection.prototype.onAdd = function (callback) {
         this.addEvent = callback;
     };
+    ElementsCollection.prototype.onReset = function (callback) {
+        this.resetEvent = callback;
+    }
 
     var AnnotationCanvasView = function (elementsCollection, image, questionId) {
         var self = this;
@@ -199,13 +210,22 @@
         this.elementsCollection.onAdd(function (pathModel) {
             self.renderElement(pathModel);
         });
+        this.elementsCollection.onReset(function () {
+            $(self.el.parentNode).children('input').remove();
+
+            self.$el.children('text, path').remove();
+
+            $('#annotation-toolbar-' + self.questionId + ' ul').empty();
+        })
 
         this.$rdbOptions = null;
+        this.$btnReset = null;
     };
     AnnotationCanvasView.prototype.render = function () {
-        this.setEvents();
-
         this.$rdbOptions = $('[name="' + this.questionId + '-options"]');
+        this.$btnReset = $('#btn-reset-' + this.questionId);
+
+        this.setEvents();
 
         return this;
     };
@@ -264,6 +284,12 @@
                 elementModel = null;
                 isMoving = false;
             });
+
+        this.$btnReset.on('click', function (e) {
+            e.preventDefault();
+
+            self.elementsCollection.reset();
+        });
     };
     AnnotationCanvasView.prototype.renderElement = function (elementModel) {
         var elementView = null,