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 "nsQueryFrame.h"
  47 #include "nsIContent.h"
  48
  49 class nsIFrame;
  50 template <class T> class nsTArray;
  51
  52 /**
  53  * Any source for anonymous content can implement this interface to provide it.
  54  * HTML frames like nsFileControlFrame currently use this.
  55  *
  56  * @see nsCSSFrameConstructor
  57  */
  58 class nsIAnonymousContentCreator
  59 {
  60 public:
  61   NS_DECL_QUERYFRAME_TARGET(nsIAnonymousContentCreator)
  62
  63   /**
  64    * Creates "native" anonymous content and adds the created content to
  65    * the aElements array. None of the returned elements can be nsnull.
  66    *
  67    * @note The returned elements are owned by this object. This object is
  68    *       responsible for calling UnbindFromTree on the elements it returned
  69    *       from CreateAnonymousContent when appropriate (i.e. before releasing
  70    *       them).
  71    */
  72   virtual nsresult CreateAnonymousContent(nsTArray<nsIContent*>& aElements)=0;
  73
  74   /**
  75    * Appends "native" anonymous children created by CreateAnonymousContent()
  76    * to the given content list.
  77    */
  78   virtual void AppendAnonymousContentTo(nsBaseContentList& aElements) = 0;
  79
  80   /**
  81    * Implementations can override this method to create special frames for the
  82    * anonymous content returned from CreateAnonymousContent.
  83    * By default this method returns nsnull, which means the default frame
  84    * is created.
  85    */
  86   virtual nsIFrame* CreateFrameFor(nsIContent* aContent) { return nsnull; }
  87 };
  88
  89 #endif
  90