layout/generic/nsIAnonymousContentCreator.h

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  37
  38 /*
  39  * interface for rendering objects that manually create subtrees of
  40  * anonymous content
  41  */
  42
  43 #ifndef nsIAnonymousContentCreator_h___
  44 #define nsIAnonymousContentCreator_h___
  45
  46 #include "nsISupports.h"
  47 #include "nsIContent.h"
  48
  49 class nsPresContext;
  50 class nsIFrame;
  51 template <class T> class nsTArray;
  52
  53 // {7568a516-3831-4db4-88a7-a42578acc136}
  54 #define NS_IANONYMOUS_CONTENT_CREATOR_IID \
  55 { 0x7568a516, 0x3831, 0x4db4, \
  56   { 0x88, 0xa7, 0xa4, 0x25, 0x78, 0xac, 0xc1, 0x36 } }
  57
  58
  59 /**
  60  * Any source for anonymous content can implement this interface to provide it.
  61  * HTML frames like nsFileControlFrame currently use this as well as XUL frames
  62  * like nsScrollbarFrame and nsSliderFrame.
  63  *
  64  * @see nsCSSFrameConstructor
  65  */
  66 class nsIAnonymousContentCreator : public nsISupports {
  67 public:
  68   NS_DECLARE_STATIC_IID_ACCESSOR(NS_IANONYMOUS_CONTENT_CREATOR_IID)
  69
  70   /**
  71    * Creates "native" anonymous content and adds the created content to
  72    * the aElements array. None of the returned elements can be nsnull.
  73    *
  74    * @note The returned elements are owned by this object. This object is
  75    *       responsible for calling UnbindFromTree on the elements it returned
  76    *       from CreateAnonymousContent when appropriate (i.e. before releasing
  77    *       them).
  78    */
  79   virtual nsresult CreateAnonymousContent(nsTArray<nsIContent*>& aElements)=0;
  80
  81   /**
  82    * Implementations can override this method to create special frames for the
  83    * anonymous content returned from CreateAnonymousContent.
  84    * By default this method returns nsnull, which means the default frame
  85    * is created.
  86    */
  87   virtual nsIFrame* CreateFrameFor(nsIContent* aContent) { return nsnull; }
  88
  89   /**
  90    * This gets called after the frames for the anonymous content have been
  91    * created and added to the frame tree. By default it does nothing.
  92    */
  93   virtual void PostCreateFrames() {}
  94 };
  95
  96 NS_DEFINE_STATIC_IID_ACCESSOR(nsIAnonymousContentCreator,
  97                               NS_IANONYMOUS_CONTENT_CREATOR_IID)
  98
  99 #endif
 100