Dispatch event on preview request

lib/private/Preview/Generator.php

@@ -32,6 +32,8 @@
 use OCP\IImage;
 use OCP\IPreview;
 use OCP\Preview\IProvider;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\EventDispatcher\GenericEvent;
 
 class Generator {
 
@@ -43,23 +45,28 @@ class Generator {
 	private $appData;
 	/** @var GeneratorHelper */
 	private $helper;
+	/** @var EventDispatcherInterface */
+	private $eventDispatcher;
 
 	/**
 	 * @param IConfig $config
 	 * @param IPreview $previewManager
 	 * @param IAppData $appData
 	 * @param GeneratorHelper $helper
+	 * @param EventDispatcherInterface $eventDispatcher
 	 */
 	public function __construct(
 		IConfig $config,
 		IPreview $previewManager,
 		IAppData $appData,
-		GeneratorHelper $helper
+		GeneratorHelper $helper,
+		EventDispatcherInterface $eventDispatcher
 	) {
 		$this->config = $config;
 		$this->previewManager = $previewManager;
 		$this->appData = $appData;
 		$this->helper = $helper;
+		$this->eventDispatcher = $eventDispatcher;
 	}
 
 	/**
@@ -78,6 +85,16 @@ public function __construct(
 	 * @throws NotFoundException
 	 */
 	public function getPreview(File $file, $width = -1, $height = -1, $crop = false, $mode = IPreview::MODE_FILL, $mimeType = null) {
+		$this->eventDispatcher->dispatch(
+			IPreview::EVENT,
+			new GenericEvent($file,[
+				'width' => $width,
+				'height' => $height,
+				'crop' => $crop,
+				'mode' => $mode
+			])
+		);
+
 		if ($mimeType === null) {
 			$mimeType = $file->getMimeType();
 		}

lib/private/PreviewManager.php

@@ -35,6 +35,7 @@
 use OCP\IConfig;
 use OCP\IPreview;
 use OCP\Preview\IProvider;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 class PreviewManager implements IPreview {
 	/** @var IConfig */
@@ -46,6 +47,9 @@ class PreviewManager implements IPreview {
 	/** @var IAppData */
 	protected $appData;
 
+	/** @var EventDispatcherInterface */
+	protected $eventDispatcher;
+
 	/** @var Generator */
 	private $generator;
 
@@ -65,16 +69,21 @@ class PreviewManager implements IPreview {
 	protected $defaultProviders;
 
 	/**
-	 * Constructor
+	 * PreviewManager constructor.
 	 *
-	 * @param \OCP\IConfig $config
+	 * @param IConfig $config
+	 * @param IRootFolder $rootFolder
+	 * @param IAppData $appData
+	 * @param EventDispatcherInterface $eventDispatcher
 	 */
 	public function __construct(IConfig $config,
 								IRootFolder $rootFolder,
-								IAppData $appData) {
+								IAppData $appData,
+								EventDispatcherInterface $eventDispatcher) {
 		$this->config = $config;
 		$this->rootFolder = $rootFolder;
 		$this->appData = $appData;
+		$this->eventDispatcher = $eventDispatcher;
 	}
 
 	/**
@@ -165,7 +174,8 @@ public function getPreview(File $file, $width = -1, $height = -1, $crop = false,
 				$this->appData,
 				new GeneratorHelper(
 					$this->rootFolder
-				)
+				),
+				$this->eventDispatcher
 			);
 		}
 

lib/private/Server.php

@@ -121,7 +121,8 @@ public function __construct($webRoot, \OC\Config $config) {
 			return new PreviewManager(
 				$c->getConfig(),
 				$c->getRootFolder(),
-				$c->getAppDataDir('preview')
+				$c->getAppDataDir('preview'),
+				$c->getEventDispatcher()
 			);
 		});
 

lib/public/IPreview.php

@@ -43,6 +43,11 @@
  */
 interface IPreview {
 
+	/**
+	 * @since 9.2.0
+	 */
+	const EVENT = self::class . ':' . 'PreviewRequested';
+
 	const MODE_FILL = 'fill';
 	const MODE_COVER = 'cover';
 

tests/lib/Preview/GeneratorTest.php

@@ -33,6 +33,8 @@
 use OCP\IImage;
 use OCP\IPreview;
 use OCP\Preview\IProvider;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\EventDispatcher\GenericEvent;
 
 class GeneratorTest extends \Test\TestCase {
 
@@ -48,6 +50,9 @@ class GeneratorTest extends \Test\TestCase {
 	/** @var GeneratorHelper|\PHPUnit_Framework_MockObject_MockObject */
 	private $helper;
 
+	/** @var EventDispatcherInterface|\PHPUnit_Framework_MockObject_MockObject */
+	private $eventDispatcher;
+
 	/** @var Generator */
 	private $generator;
 
@@ -58,12 +63,14 @@ public function setUp() {
 		$this->previewManager = $this->createMock(IPreview::class);
 		$this->appData = $this->createMock(IAppData::class);
 		$this->helper = $this->createMock(GeneratorHelper::class);
+		$this->eventDispatcher = $this->createMock(EventDispatcherInterface::class);
 
 		$this->generator = new Generator(
 			$this->config,
 			$this->previewManager,
 			$this->appData,
-			$this->helper
+			$this->helper,
+			$this->eventDispatcher
 		);
 	}
 
@@ -96,6 +103,17 @@ public function testGetCachedPreview() {
 			->with($this->equalTo('128-128.png'))
 			->willReturn($previewFile);
 
+		$this->eventDispatcher->expects($this->once())
+			->method('dispatch')
+			->with(
+				$this->equalTo(IPreview::EVENT),
+				$this->callback(function(GenericEvent $event) use ($file) {
+					return $event->getSubject() === $file &&
+						$event->getArgument('width') === 100 &&
+						$event->getArgument('height') === 100;
+				})
+			);
+
 		$result = $this->generator->getPreview($file, 100, 100);
 		$this->assertSame($previewFile, $result);
 	}
@@ -204,6 +222,17 @@ public function testGetNewPreview() {
 			->method('putContent')
 			->with('my resized data');
 
+		$this->eventDispatcher->expects($this->once())
+			->method('dispatch')
+			->with(
+				$this->equalTo(IPreview::EVENT),
+				$this->callback(function(GenericEvent $event) use ($file) {
+					return $event->getSubject() === $file &&
+					$event->getArgument('width') === 100 &&
+					$event->getArgument('height') === 100;
+				})
+			);
+
 		$result = $this->generator->getPreview($file, 100, 100);
 		$this->assertSame($previewFile, $result);
 	}
@@ -217,6 +246,19 @@ public function testInvalidMimeType() {
 			->with('invalidType')
 			->willReturn(false);
 
+		$this->eventDispatcher->expects($this->once())
+			->method('dispatch')
+			->with(
+				$this->equalTo(IPreview::EVENT),
+				$this->callback(function(GenericEvent $event) use ($file) {
+					return $event->getSubject() === $file &&
+					$event->getArgument('width') === 0 &&
+					$event->getArgument('height') === 0 &&
+					$event->getArgument('crop') === true &&
+					$event->getArgument('mode') === IPreview::MODE_COVER;
+				})
+			);
+
 		$this->generator->getPreview($file, 0, 0, true, IPreview::MODE_COVER, 'invalidType');
 	}
 
@@ -242,6 +284,17 @@ public function testNoProvider() {
 		$this->previewManager->method('getProviders')
 			->willReturn([]);
 
+		$this->eventDispatcher->expects($this->once())
+			->method('dispatch')
+			->with(
+				$this->equalTo(IPreview::EVENT),
+				$this->callback(function(GenericEvent $event) use ($file) {
+					return $event->getSubject() === $file &&
+					$event->getArgument('width') === 100 &&
+					$event->getArgument('height') === 100;
+				})
+			);
+
 		$this->expectException(NotFoundException::class);
 		$this->generator->getPreview($file, 100, 100);
 	}
@@ -332,6 +385,19 @@ public function testCorrectSize($maxX, $maxY, $reqX, $reqY, $crop, $mode, $expec
 			->with($this->equalTo($filename))
 			->willReturn($preview);
 
+		$this->eventDispatcher->expects($this->once())
+			->method('dispatch')
+			->with(
+				$this->equalTo(IPreview::EVENT),
+				$this->callback(function(GenericEvent $event) use ($file, $reqX, $reqY, $crop, $mode) {
+					return $event->getSubject() === $file &&
+					$event->getArgument('width') === $reqX &&
+					$event->getArgument('height') === $reqY &&
+					$event->getArgument('crop') === $crop &&
+					$event->getArgument('mode') === $mode;
+				})
+			);
+
 		$result = $this->generator->getPreview($file, $reqX, $reqY, $crop, $mode);
 		$this->assertSame($preview, $result);
 	}