layout/style/ImageLoader.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   3  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 // A class that handles style system image loads (other image loads are handled
   6 // by the nodes in the content tree).
   7
   8 #ifndef mozilla_css_ImageLoader_h___
   9 #define mozilla_css_ImageLoader_h___
  10
  11 #include "nsClassHashtable.h"
  12 #include "nsHashKeys.h"
  13 #include "nsTArray.h"
  14 #include "imgIRequest.h"
  15 #include "imgIOnloadBlocker.h"
  16 #include "imgINotificationObserver.h"
  17 #include "mozilla/Attributes.h"
  18
  19 class imgIContainer;
  20 class nsIFrame;
  21 class nsIDocument;
  22 class nsPresContext;
  23 class nsIURI;
  24 class nsIPrincipal;
  25
  26 namespace mozilla {
  27 namespace css {
  28
  29 struct ImageValue;
  30
  31 class ImageLoader MOZ_FINAL : public imgINotificationObserver,
  32                               public imgIOnloadBlocker {
  33 public:
  34   typedef mozilla::css::ImageValue Image;
  35
  36   explicit ImageLoader(nsIDocument* aDocument)
  37   : mDocument(aDocument),
  38     mInClone(false)
  39   {
  40     MOZ_ASSERT(mDocument);
  41   }
  42
  43   NS_DECL_ISUPPORTS
  44   NS_DECL_IMGIONLOADBLOCKER
  45   NS_DECL_IMGINOTIFICATIONOBSERVER
  46
  47   void DropDocumentReference();
  48
  49   void MaybeRegisterCSSImage(Image* aImage);
  50   void DeregisterCSSImage(Image* aImage);
  51
  52   void AssociateRequestToFrame(imgIRequest* aRequest,
  53                                nsIFrame* aFrame);
  54
  55   void DisassociateRequestFromFrame(imgIRequest* aRequest,
  56                                     nsIFrame* aFrame);
  57
  58   void DropRequestsForFrame(nsIFrame* aFrame);
  59
  60   void SetAnimationMode(uint16_t aMode);
  61
  62   void ClearFrames();
  63
  64   void LoadImage(nsIURI* aURI, nsIPrincipal* aPrincipal, nsIURI* aReferrer,
  65                  Image* aCSSValue);
  66
  67   void DestroyRequest(imgIRequest* aRequest);
  68
  69 private:
  70   ~ImageLoader() {}
  71
  72   // We need to be able to look up the frames associated with a request (for
  73   // delivering notifications) and the requests associated with a frame (when
  74   // the frame goes away). Thus we maintain hashtables going both ways.  These
  75   // should always be in sync.
  76
  77   typedef nsTArray<nsIFrame*> FrameSet;
  78   typedef nsTArray<nsCOMPtr<imgIRequest> > RequestSet;
  79   typedef nsTHashtable<nsPtrHashKey<Image> > ImageHashSet;
  80   typedef nsClassHashtable<nsISupportsHashKey,
  81                            FrameSet> RequestToFrameMap;
  82   typedef nsClassHashtable<nsPtrHashKey<nsIFrame>,
  83                            RequestSet> FrameToRequestMap;
  84
  85   void AddImage(Image* aCSSImage);
  86   void RemoveImage(Image* aCSSImage);
  87
  88   nsPresContext* GetPresContext();
  89
  90   void DoRedraw(FrameSet* aFrameSet);
  91
  92   static PLDHashOperator
  93   SetAnimationModeEnumerator(nsISupports* aKey, FrameSet* aValue,
  94                              void* aClosure);
  95
  96   nsresult OnStartContainer(imgIRequest *aRequest, imgIContainer* aImage);
  97   nsresult OnStopFrame(imgIRequest *aRequest);
  98   nsresult OnImageIsAnimated(imgIRequest *aRequest);
  99   nsresult FrameChanged(imgIRequest* aRequest);
 100   // Do not override OnDataAvailable since background images are not
 101   // displayed incrementally; they are displayed after the entire image
 102   // has been loaded.
 103
 104   // A map of imgIRequests to the nsIFrames that are using them.
 105   RequestToFrameMap mRequestToFrameMap;
 106
 107   // A map of nsIFrames to the imgIRequests they use.
 108   FrameToRequestMap mFrameToRequestMap;
 109
 110   // A weak pointer to our document. Nulled out by DropDocumentReference.
 111   nsIDocument* mDocument;
 112
 113   // The set of all nsCSSValue::Images (whether they're associated a frame or
 114   // not).  We'll need this when we go away to remove any requests associated
 115   // with our document from those Images.
 116   ImageHashSet mImages;
 117
 118   // Are we cloning?  If so, ignore any notifications we get.
 119   bool mInClone;
 120 };
 121
 122 } // namespace css
 123 } // namespace mozilla
 124
 125 #endif /* mozilla_css_ImageLoader_h___ */