diff -r 000000000000 -r 6474c204b198 image/src/ClippedImage.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/image/src/ClippedImage.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,97 @@
+/* -*- 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_IMAGELIB_CLIPPEDIMAGE_H_
+#define MOZILLA_IMAGELIB_CLIPPEDIMAGE_H_
+
+#include "ImageWrapper.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/RefPtr.h"
+
+namespace mozilla {
+namespace image {
+
+class ClippedImageCachedSurface;
+class DrawSingleTileCallback;
+
+/**
+ * An Image wrapper that clips an image against a rectangle. Right now only
+ * absolute coordinates in pixels are supported.
+ *
+ * XXX(seth): There a known (performance, not correctness) issue with
+ * GetImageContainer. See the comments for that method for more information.
+ */
+class ClippedImage : public ImageWrapper
+{
+  typedef mozilla::gfx::SourceSurface SourceSurface;
+
+public:
+  NS_DECL_ISUPPORTS
+
+  virtual ~ClippedImage();
+
+  virtual nsIntRect FrameRect(uint32_t aWhichFrame) MOZ_OVERRIDE;
+
+  NS_IMETHOD GetWidth(int32_t* aWidth) MOZ_OVERRIDE;
+  NS_IMETHOD GetHeight(int32_t* aHeight) MOZ_OVERRIDE;
+  NS_IMETHOD GetIntrinsicSize(nsSize* aSize) MOZ_OVERRIDE;
+  NS_IMETHOD GetIntrinsicRatio(nsSize* aRatio) MOZ_OVERRIDE;
+  NS_IMETHOD_(mozilla::TemporaryRef<SourceSurface>)
+    GetFrame(uint32_t aWhichFrame, uint32_t aFlags) MOZ_OVERRIDE;
+  NS_IMETHOD GetImageContainer(mozilla::layers::LayerManager* aManager,
+                               mozilla::layers::ImageContainer** _retval) MOZ_OVERRIDE;
+  NS_IMETHOD Draw(gfxContext* aContext,
+                  GraphicsFilter aFilter,
+                  const gfxMatrix& aUserSpaceToImageSpace,
+                  const gfxRect& aFill,
+                  const nsIntRect& aSubimage,
+                  const nsIntSize& aViewportSize,
+                  const SVGImageContext* aSVGContext,
+                  uint32_t aWhichFrame,
+                  uint32_t aFlags) MOZ_OVERRIDE;
+  NS_IMETHOD RequestDiscard() MOZ_OVERRIDE;
+  NS_IMETHOD_(Orientation) GetOrientation() MOZ_OVERRIDE;
+
+protected:
+  ClippedImage(Image* aImage, nsIntRect aClip);
+
+private:
+  mozilla::TemporaryRef<SourceSurface>
+    GetFrameInternal(const nsIntSize& aViewportSize,
+                     const SVGImageContext* aSVGContext,
+                     uint32_t aWhichFrame,
+                     uint32_t aFlags);
+  bool ShouldClip();
+  bool MustCreateSurface(gfxContext* aContext,
+                         const gfxMatrix& aTransform,
+                         const gfxRect& aSourceRect,
+                         const nsIntRect& aSubimage,
+                         const uint32_t aFlags) const;
+  gfxFloat ClampFactor(const gfxFloat aToClamp, const int aReference) const;
+  nsresult DrawSingleTile(gfxContext* aContext,
+                          GraphicsFilter aFilter,
+                          const gfxMatrix& aUserSpaceToImageSpace,
+                          const gfxRect& aFill,
+                          const nsIntRect& aSubimage,
+                          const nsIntSize& aViewportSize,
+                          const SVGImageContext* aSVGContext,
+                          uint32_t aWhichFrame,
+                          uint32_t aFlags);
+
+  // If we are forced to draw a temporary surface, we cache it here.
+  nsAutoPtr<ClippedImageCachedSurface> mCachedSurface;
+
+  nsIntRect   mClip;              // The region to clip to.
+  Maybe<bool> mShouldClip;        // Memoized ShouldClip() if present.
+
+  friend class DrawSingleTileCallback;
+  friend class ImageOps;
+};
+
+} // namespace image
+} // namespace mozilla
+
+#endif // MOZILLA_IMAGELIB_CLIPPEDIMAGE_H_