third_party/WebKit/Source/core/fetch/ImageResourceClient.h

   1 /*
   2     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
   3     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
   4     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
   5     Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
   6
   7     This library is free software; you can redistribute it and/or
   8     modify it under the terms of the GNU Library General Public
   9     License as published by the Free Software Foundation; either
  10     version 2 of the License, or (at your option) any later version.
  11
  12     This library is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15     Library General Public License for more details.
  16
  17     You should have received a copy of the GNU Library General Public License
  18     along with this library; see the file COPYING.LIB.  If not, write to
  19     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20     Boston, MA 02110-1301, USA.
  21 */
  22
  23 #ifndef ImageResourceClient_h
  24 #define ImageResourceClient_h
  25
  26 #include "core/CoreExport.h"
  27 #include "core/fetch/ResourceClient.h"
  28 #include "platform/graphics/ImageAnimationPolicy.h"
  29
  30 namespace blink {
  31
  32 class ImageResource;
  33 class IntRect;
  34
  35 class CORE_EXPORT ImageResourceClient : public ResourceClient {
  36 public:
  37     ~ImageResourceClient() override {}
  38     static ResourceClientType expectedType() { return ImageType; }
  39     ResourceClientType resourceClientType() const final { return expectedType(); }
  40
  41     // Called whenever a frame of an image changes, either because we got more data from the network or
  42     // because we are animating. If not null, the IntRect is the changed rect of the image.
  43     virtual void imageChanged(ImageResource*, const IntRect* = 0) { }
  44
  45     // Called to find out if this client wants to actually display the image. Used to tell when we
  46     // can halt animation. Content nodes that hold image refs for example would not render the image,
  47     // but LayoutImages would (assuming they have visibility: visible and their layout tree isn't hidden
  48     // e.g., in the b/f cache or in a background tab).
  49     virtual bool willRenderImage(ImageResource*) { return false; }
  50
  51     // Called to get imageAnimation policy from settings
  52     virtual bool getImageAnimationPolicy(ImageResource*, ImageAnimationPolicy&) { return false; }
  53 };
  54
  55 }
  56
  57 #endif