layout/generic/nsSplittableFrame.h

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  37
  38 /*
  39  * base class for rendering objects that can be split across lines,
  40  * columns, or pages
  41  */
  42
  43 #ifndef nsSplittableFrame_h___
  44 #define nsSplittableFrame_h___
  45
  46 #include "nsFrame.h"
  47
  48 // Derived class that allows splitting
  49 class nsSplittableFrame : public nsFrame
  50 {
  51 public:
  52   NS_IMETHOD Init(nsIContent*      aContent,
  53                   nsIFrame*        aParent,
  54                   nsIFrame*        aPrevInFlow);
  55
  56   virtual nsSplittableType GetSplittableType() const;
  57
  58   virtual void Destroy();
  59
  60   /*
  61    * Frame continuations can be either fluid or not:
  62    * Fluid continuations ("in-flows") are the result of line breaking,
  63    * column breaking, or page breaking.
  64    * Other (non-fluid) continuations can be the result of BiDi frame splitting.
  65    * A "flow" is a chain of fluid continuations.
  66    */
  67
  68   // Get the previous/next continuation, regardless of its type (fluid or non-fluid).
  69   virtual nsIFrame* GetPrevContinuation() const;
  70   virtual nsIFrame* GetNextContinuation() const;
  71
  72   // Set a previous/next non-fluid continuation.
  73   NS_IMETHOD SetPrevContinuation(nsIFrame*);
  74   NS_IMETHOD SetNextContinuation(nsIFrame*);
  75
  76   // Get the first/last continuation for this frame.
  77   virtual nsIFrame* GetFirstContinuation() const;
  78   virtual nsIFrame* GetLastContinuation() const;
  79
  80 #ifdef DEBUG
  81   // Can aFrame2 be reached from aFrame1 by following prev/next continuations?
  82   static PRBool IsInPrevContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2);
  83   static PRBool IsInNextContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2);
  84 #endif
  85
  86   // Get the previous/next continuation, only if it is fluid (an "in-flow").
  87   nsIFrame* GetPrevInFlow() const;
  88   nsIFrame* GetNextInFlow() const;
  89
  90   virtual nsIFrame* GetPrevInFlowVirtual() const { return GetPrevInFlow(); }
  91   virtual nsIFrame* GetNextInFlowVirtual() const { return GetNextInFlow(); }
  92
  93   // Set a previous/next fluid continuation.
  94   NS_IMETHOD  SetPrevInFlow(nsIFrame*);
  95   NS_IMETHOD  SetNextInFlow(nsIFrame*);
  96
  97   // Get the first/last frame in the current flow.
  98   virtual nsIFrame* GetFirstInFlow() const;
  99   virtual nsIFrame* GetLastInFlow() const;
 100
 101   // Remove the frame from the flow. Connects the frame's prev-in-flow
 102   // and its next-in-flow
 103   static void RemoveFromFlow(nsIFrame* aFrame);
 104
 105   // Detach from previous frame in flow
 106   static void BreakFromPrevFlow(nsIFrame* aFrame);
 107
 108 protected:
 109   nsSplittableFrame(nsStyleContext* aContext) : nsFrame(aContext) {}
 110
 111 #ifdef DEBUG
 112   virtual void DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent, PRBool aIncludeStyleData);
 113 #endif
 114
 115   nsIFrame*   mPrevContinuation;
 116   nsIFrame*   mNextContinuation;
 117 };
 118
 119 #endif /* nsSplittableFrame_h___ */