image/src/ClippedImage.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef MOZILLA_IMAGELIB_CLIPPEDIMAGE_H_
   7 #define MOZILLA_IMAGELIB_CLIPPEDIMAGE_H_
   8
   9 #include "ImageWrapper.h"
  10 #include "mozilla/gfx/2D.h"
  11 #include "mozilla/Maybe.h"
  12 #include "mozilla/RefPtr.h"
  13
  14 namespace mozilla {
  15 namespace image {
  16
  17 class ClippedImageCachedSurface;
  18 class DrawSingleTileCallback;
  19
  20 /**
  21  * An Image wrapper that clips an image against a rectangle. Right now only
  22  * absolute coordinates in pixels are supported.
  23  *
  24  * XXX(seth): There a known (performance, not correctness) issue with
  25  * GetImageContainer. See the comments for that method for more information.
  26  */
  27 class ClippedImage : public ImageWrapper
  28 {
  29   typedef gfx::SourceSurface SourceSurface;
  30
  31 public:
  32   NS_DECL_ISUPPORTS_INHERITED
  33
  34   virtual nsIntRect FrameRect(uint32_t aWhichFrame) MOZ_OVERRIDE;
  35
  36   NS_IMETHOD GetWidth(int32_t* aWidth) MOZ_OVERRIDE;
  37   NS_IMETHOD GetHeight(int32_t* aHeight) MOZ_OVERRIDE;
  38   NS_IMETHOD GetIntrinsicSize(nsSize* aSize) MOZ_OVERRIDE;
  39   NS_IMETHOD GetIntrinsicRatio(nsSize* aRatio) MOZ_OVERRIDE;
  40   NS_IMETHOD_(TemporaryRef<SourceSurface>)
  41     GetFrame(uint32_t aWhichFrame, uint32_t aFlags) MOZ_OVERRIDE;
  42   NS_IMETHOD GetImageContainer(layers::LayerManager* aManager,
  43                                layers::ImageContainer** _retval) MOZ_OVERRIDE;
  44   NS_IMETHOD Draw(gfxContext* aContext,
  45                   const nsIntSize& aSize,
  46                   const ImageRegion& aRegion,
  47                   uint32_t aWhichFrame,
  48                   GraphicsFilter aFilter,
  49                   const Maybe<SVGImageContext>& aSVGContext,
  50                   uint32_t aFlags) MOZ_OVERRIDE;
  51   NS_IMETHOD RequestDiscard() MOZ_OVERRIDE;
  52   NS_IMETHOD_(Orientation) GetOrientation() MOZ_OVERRIDE;
  53   NS_IMETHOD_(nsIntRect) GetImageSpaceInvalidationRect(const nsIntRect& aRect) MOZ_OVERRIDE;
  54   nsIntSize OptimalImageSizeForDest(const gfxSize& aDest,
  55                                     uint32_t aWhichFrame,
  56                                     GraphicsFilter aFilter,
  57                                     uint32_t aFlags) MOZ_OVERRIDE;
  58
  59 protected:
  60   ClippedImage(Image* aImage, nsIntRect aClip);
  61
  62   virtual ~ClippedImage();
  63
  64 private:
  65   TemporaryRef<SourceSurface>
  66     GetFrameInternal(const nsIntSize& aSize,
  67                      const Maybe<SVGImageContext>& aSVGContext,
  68                      uint32_t aWhichFrame,
  69                      uint32_t aFlags);
  70   bool ShouldClip();
  71   nsresult DrawSingleTile(gfxContext* aContext,
  72                           const nsIntSize& aSize,
  73                           const ImageRegion& aRegion,
  74                           uint32_t aWhichFrame,
  75                           GraphicsFilter aFilter,
  76                           const Maybe<SVGImageContext>& aSVGContext,
  77                           uint32_t aFlags);
  78
  79   // If we are forced to draw a temporary surface, we cache it here.
  80   nsAutoPtr<ClippedImageCachedSurface> mCachedSurface;
  81
  82   nsIntRect   mClip;              // The region to clip to.
  83   Maybe<bool> mShouldClip;        // Memoized ShouldClip() if present.
  84
  85   friend class DrawSingleTileCallback;
  86   friend class ImageOps;
  87 };
  88
  89 } // namespace image
  90 } // namespace mozilla
  91
  92 #endif // MOZILLA_IMAGELIB_CLIPPEDIMAGE_H_