Webp format should be animated (#812)

* Allow webp as animated format

* tests that show webp format cannot be used as animated

* Allow webp as animated format

* Fix style and tests

Author: Yoann-TYT

src/Gmagick/Layers.php

@@ -108,8 +108,8 @@ public function coalesce()
     public function animate($format, $delay, $loops)
     {
         $formatInfo = Format::get($format);
-        if ($formatInfo === null || $formatInfo->getID() !== Format::ID_GIF) {
-            throw new InvalidArgumentException('Animated picture is currently only supported on gif');
+        if ($formatInfo === null || !in_array($formatInfo->getID(), array(Format::ID_GIF, Format::ID_WEBP))) {
+            throw new InvalidArgumentException('Animated picture is currently only supported on gif and webp');
         }
 
         if (!is_int($loops) || $loops < 0) {

src/Imagick/Layers.php

@@ -92,8 +92,8 @@ public function merge()
     public function animate($format, $delay, $loops)
     {
         $formatInfo = Format::get($format);
-        if ($formatInfo === null || $formatInfo->getID() !== Format::ID_GIF) {
-            throw new InvalidArgumentException('Animated picture is currently only supported on gif');
+        if ($formatInfo === null || !in_array($formatInfo->getID(), array(Format::ID_GIF, Format::ID_WEBP))) {
+            throw new InvalidArgumentException('Animated picture is currently only supported on gif and webp');
         }
 
         if (!is_int($loops) || $loops < 0) {
@@ -107,7 +107,7 @@ public function animate($format, $delay, $loops)
         try {
             foreach ($this as $offset => $layer) {
                 $this->resource->setIteratorIndex($offset);
-                $this->resource->setFormat(Format::ID_GIF);
+                $this->resource->setFormat($formatInfo->getID());
 
                 if ($delay !== null) {
                     $layer->getImagick()->setImageDelay($delay / 10);

tests/tests/Gmagick/LayersTest.php

@@ -84,6 +84,20 @@ public function testCount()
         $this->assertCount(42, $layers);
     }
 
+    public function testWebpFormatIsAllowedAsAnimatedFormat()
+    {
+        $palette = new RGB();
+        $resource = $this->getMockBuilder('\Gmagick')->getMock();
+
+        $resource->expects($this->atLeastOnce())
+            ->method('getNumberImages')
+            ->will($this->returnValue(42));
+
+        $layers = new Layers(new Image($resource, $palette, new MetadataBag()), $palette, $resource);
+
+        $layers->animate('webp', 200, 0);
+    }
+
     public function testGetLayer()
     {
         $this->checkGmagickMockable();

tests/tests/Imagick/LayersTest.php

@@ -83,6 +83,20 @@ public function testCount()
         $this->assertCount(42, $layers);
     }
 
+    public function testWebpFormatIsAllowedAsAnimatedFormat()
+    {
+        $palette = new RGB();
+        $resource = $this->getMockBuilder('\Imagick')->getMock();
+
+        $resource->expects($this->atLeastOnce())
+            ->method('getNumberImages')
+            ->will($this->returnValue(42));
+
+        $layers = new Layers(new Image($resource, $palette, new MetadataBag()), $palette, $resource);
+
+        $layers->animate('webp', 200, 0);
+    }
+
     public function testGetLayer()
     {
         $palette = new RGB();