1 files changed, 73 insertions, 0 deletions
diff --git a/image/FrozenImage.h b/image/FrozenImage.h
new file mode 100644
index 000000000..24b57304e
--- /dev/null
+++ b/image/FrozenImage.h
@@ -0,0 +1,73 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_FrozenImage_h
+#define mozilla_image_FrozenImage_h
+
+#include "ImageWrapper.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/RefPtr.h"
+
+namespace mozilla {
+namespace image {
+
+/**
+ * An Image wrapper that disables animation, freezing the image at its first
+ * frame. It does this using two strategies. If this is the only instance of the
+ * image, animation will never start, because IncrementAnimationConsumers is
+ * ignored. If there is another instance that is animated, that's still OK,
+ * because any imgIContainer method that is affected by animation gets its
+ * aWhichFrame argument set to FRAME_FIRST when it passes through FrozenImage.
+ *
+ * XXX(seth): There a known (performance, not correctness) issue with
+ * GetImageContainer. See the comments for that method for more information.
+ */
+class FrozenImage : public ImageWrapper
+{
+  typedef gfx::SourceSurface SourceSurface;
+
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+
+  virtual void IncrementAnimationConsumers() override;
+  virtual void DecrementAnimationConsumers() override;
+
+  NS_IMETHOD GetAnimated(bool* aAnimated) override;
+  NS_IMETHOD_(already_AddRefed<SourceSurface>)
+    GetFrame(uint32_t aWhichFrame, uint32_t aFlags) override;
+  NS_IMETHOD_(already_AddRefed<SourceSurface>)
+    GetFrameAtSize(const gfx::IntSize& aSize,
+                   uint32_t aWhichFrame,
+                   uint32_t aFlags) override;
+  NS_IMETHOD_(bool) IsImageContainerAvailable(layers::LayerManager* aManager,
+                                              uint32_t aFlags) override;
+  NS_IMETHOD_(already_AddRefed<layers::ImageContainer>)
+    GetImageContainer(layers::LayerManager* aManager,
+                      uint32_t aFlags) override;
+  NS_IMETHOD_(DrawResult) Draw(gfxContext* aContext,
+                               const nsIntSize& aSize,
+                               const ImageRegion& aRegion,
+                               uint32_t aWhichFrame,
+                               gfx::SamplingFilter aSamplingFilter,
+                               const Maybe<SVGImageContext>& aSVGContext,
+                               uint32_t aFlags) override;
+  NS_IMETHOD_(void) RequestRefresh(const TimeStamp& aTime) override;
+  NS_IMETHOD GetAnimationMode(uint16_t* aAnimationMode) override;
+  NS_IMETHOD SetAnimationMode(uint16_t aAnimationMode) override;
+  NS_IMETHOD ResetAnimation() override;
+  NS_IMETHOD_(float) GetFrameIndex(uint32_t aWhichFrame) override;
+
+protected:
+  explicit FrozenImage(Image* aImage) : ImageWrapper(aImage) { }
+  virtual ~FrozenImage() { }
+
+private:
+  friend class ImageOps;
+};
+
+} // namespace image
+} // namespace mozilla
+
+#endif // mozilla_image_FrozenImage_h