Merge pull request #4966 from owncloud/text_preview_blacklist

add blacklist to txt preview backend

* owncloud/text_preview_blacklist:
  rename variable in testIsTransparent
  rename testTxtBlacklist to txtBlacklist
  move fileView object initialization to testIsTransparent
  use dataProvider for txt blacklist test
  add test for txt blacklist
  add test data for cal and contact preview
  add blacklist to txt preview backend

lib/preview/txt.php

@@ -9,11 +9,21 @@ namespace OC\Preview;
 
 class TXT extends Provider {
 
+	private static $blacklist = array(
+		'text/calendar',
+		'text/vcard',
+	);
+
 	public function getMimeType() {
 		return '/text\/.*/';
 	}
 
 	public function getThumbnail($path, $maxX, $maxY, $scalingup, $fileview) {
+		$mimetype = $fileview->getMimeType($path);
+		if(in_array($mimetype, self::$blacklist)) {
+			return false;
+		}
+
 		$content = $fileview->fopen($path, 'r');
 		$content = stream_get_contents($content);
 

tests/data/testcal.ics

@@ -0,0 +1,13 @@
+BEGIN:VCALENDAR
+PRODID:-//some random cal software//EN
+VERSION:2.0
+BEGIN:VEVENT
+CREATED:20130102T120000Z
+LAST-MODIFIED:20130102T120000Z
+DTSTAMP:20130102T120000Z
+UID:f106ecdf-c716-43ef-9d94-4e6f19f2fcfb
+SUMMARY:a test cal file
+DTSTART;VALUE=DATE:20130101
+DTEND;VALUE=DATE:20130102
+END:VEVENT
+END:VCALENDAR

tests/data/testcontact.vcf

@@ -0,0 +1,6 @@
+BEGIN:VCARD
+VERSION:3.0
+PRODID:-//some random contact software//EN
+N:def;abc;;;
+FN:abc def
+END:VCARD

tests/lib/preview.php

@@ -92,6 +92,47 @@ class Preview extends \PHPUnit_Framework_TestCase {
 		$this->assertEquals($image->height(), $maxY);
 	}
 
+	public function txtBlacklist() {
+		$txt = 'random text file';
+		$ics = file_get_contents(__DIR__ . '/../data/testcal.ics');
+		$vcf = file_get_contents(__DIR__ . '/../data/testcontact.vcf');
+
+		return array(
+			array('txt', $txt, false),
+			array('ics', $ics, true),
+			array('vcf', $vcf, true),
+		);
+	}
+
+	/**
+	 * @dataProvider txtBlacklist
+	 */
+	public function testIsTransparent($extension, $data, $expectedResult) {
+		$user = $this->initFS();
+
+		$rootView = new \OC\Files\View('');
+		$rootView->mkdir('/'.$user);
+		$rootView->mkdir('/'.$user.'/files');
+
+		$x = 32;
+		$y = 32;
+
+		$sample = '/'.$user.'/files/test.'.$extension;
+		$rootView->file_put_contents($sample, $data);
+		$preview = new \OC\Preview($user, 'files/', 'test.'.$extension, $x, $y);
+		$image = $preview->getPreview();
+		$resource = $image->resource();
+
+		//http://stackoverflow.com/questions/5702953/imagecolorat-and-transparency
+		$colorIndex = imagecolorat($resource, 1, 1);
+		$colorInfo = imagecolorsforindex($resource, $colorIndex);
+		$this->assertEquals(
+			$expectedResult,
+			$colorInfo['alpha'] === 127,
+			'Failed asserting that only previews for text files are transparent.'
+		);
+	}
+
 	private function initFS() {
 		if(\OC\Files\Filesystem::getView()){
 			$user = \OC_User::getUser();
@@ -105,4 +146,4 @@ class Preview extends \PHPUnit_Framework_TestCase {
 		
 		return $user;
 	}
-}
+}