WebCore/CachedResourceClient.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) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
   5
   6     This library is free software; you can redistribute it and/or
   7     modify it under the terms of the GNU Library General Public
   8     License as published by the Free Software Foundation; either
   9     version 2 of the License, or (at your option) any later version.
  10
  11     This library is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14     Library General Public License for more details.
  15
  16     You should have received a copy of the GNU Library General Public License
  17     along with this library; see the file COPYING.LIB.  If not, write to
  18     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19     Boston, MA 02110-1301, USA.
  20
  21     This class provides all functionality needed for loading images, style sheets and html
  22     pages from the web. It has a memory cache for these objects.
  23 */
  24
  25 #ifndef CachedResourceClient_h
  26 #define CachedResourceClient_h
  27
  28 #if ENABLE(XBL)
  29 namespace XBL {
  30     class XBLDocument;
  31 }
  32 #endif
  33
  34 namespace WebCore {
  35
  36     class CachedCSSStyleSheet;
  37     class CachedFont;
  38     class CachedResource;
  39     class CachedImage;
  40     class String;
  41     class Image;
  42     class IntRect;
  43
  44     /**
  45      * @internal
  46      *
  47      * a client who wants to load stylesheets, images or scripts from the web has to
  48      * inherit from this class and overload one of the 3 functions
  49      *
  50      */
  51     class CachedResourceClient
  52     {
  53     public:
  54         virtual ~CachedResourceClient() { }
  55
  56         // Called whenever a frame of an image changes, either because we got more data from the network or
  57         // because we are animating. If not null, the IntRect is the changed rect of the image.
  58         virtual void imageChanged(CachedImage*, const IntRect* = 0) { };
  59
  60         // Called to find out if this client wants to actually display the image.  Used to tell when we
  61         // can halt animation.  Content nodes that hold image refs for example would not render the image,
  62         // but RenderImages would (assuming they have visibility: visible and their render tree isn't hidden
  63         // e.g., in the b/f cache or in a background tab).
  64         virtual bool willRenderImage(CachedImage*) { return false; }
  65
  66         virtual bool memoryLimitReached() { return false; }
  67
  68         virtual void setCSSStyleSheet(const String& /*URL*/, const String& /*charset*/, const CachedCSSStyleSheet*) { }
  69         virtual void setXSLStyleSheet(const String& /*URL*/, const String& /*sheet*/) { }
  70
  71         virtual void fontLoaded(CachedFont*) {};
  72
  73 #if ENABLE(XBL)
  74         virtual void setXBLDocument(const String& /*URL*/, XBL::XBLDocument*) { }
  75 #endif
  76
  77         virtual void notifyFinished(CachedResource*) { }
  78     };
  79
  80 }
  81
  82 #endif