layout/generic/nsFrameList.h

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  37
  38 /* class for maintaining a linked list of child frames */
  39
  40 #ifndef nsFrameList_h___
  41 #define nsFrameList_h___
  42
  43 #include "nsIFrame.h"
  44
  45 /**
  46  * A class for managing a singly linked list of frames. Frames are
  47  * linked together through their next-sibling pointer.
  48  */
  49
  50 class nsFrameList {
  51 public:
  52   nsFrameList() {
  53     mFirstChild = nsnull;
  54   }
  55
  56   nsFrameList(nsIFrame* aHead) {
  57     mFirstChild = aHead;
  58 #ifdef DEBUG
  59     CheckForLoops();
  60 #endif
  61   }
  62
  63   ~nsFrameList() {
  64   }
  65
  66   void DestroyFrames();
  67
  68   // Delete this and destroy all its frames
  69   void Destroy();
  70
  71   void SetFrames(nsIFrame* aFrameList) {
  72     mFirstChild = aFrameList;
  73 #ifdef DEBUG
  74     CheckForLoops();
  75 #endif
  76   }
  77
  78   // Appends frames from aFrameList to this list. If aParent
  79   // is not null, reparents the newly-added frames.
  80   void AppendFrames(nsIFrame* aParent, nsIFrame* aFrameList);
  81
  82   void AppendFrames(nsIFrame* aParent, nsFrameList& aFrameList) {
  83     AppendFrames(aParent, aFrameList.mFirstChild);
  84     aFrameList.mFirstChild = nsnull;
  85   }
  86
  87   void AppendFrame(nsIFrame* aParent, nsIFrame* aFrame);
  88
  89   // Take aFrame out of the frame list. This also disconnects aFrame
  90   // from the sibling list. This will return PR_FALSE if aFrame is
  91   // nsnull or if aFrame is not in the list. The second frame is
  92   // a hint for the prev-sibling of aFrame; if the hint is correct,
  93   // then this is O(1) time. If successfully removed, the child's
  94   // NextSibling pointer is cleared.
  95   PRBool RemoveFrame(nsIFrame* aFrame, nsIFrame* aPrevSiblingHint = nsnull);
  96
  97   // Remove the first child from the list. The caller is assumed to be
  98   // holding a reference to the first child. This call is equivalent
  99   // in behavior to calling RemoveFrame(FirstChild()). If successfully
 100   // removed the first child's NextSibling pointer is cleared.
 101   PRBool RemoveFirstChild();
 102
 103   // Take aFrame out of the frame list and then destroy it. This also
 104   // disconnects aFrame from the sibling list. This will return
 105   // PR_FALSE if aFrame is nsnull or if aFrame is not in the list.
 106   PRBool DestroyFrame(nsIFrame* aFrame);
 107
 108   // Inserts aNewFrame right after aPrevSibling, or prepends to
 109   // list if aPrevSibling is null. If aParent is not null, also
 110   // reparents newly-added frame. Note that this method always
 111   // sets the frame's nextSibling pointer.
 112   void InsertFrame(nsIFrame* aParent,
 113                    nsIFrame* aPrevSibling,
 114                    nsIFrame* aNewFrame);
 115
 116   // Inserts aFrameList right after aPrevSibling, or prepends to
 117   // list if aPrevSibling is null. If aParent is not null, also
 118   // reparents newly-added frame.
 119   void InsertFrames(nsIFrame* aParent,
 120                     nsIFrame* aPrevSibling,
 121                     nsIFrame* aFrameList);
 122
 123   void InsertFrames(nsIFrame* aParent, nsIFrame* aPrevSibling,
 124                     nsFrameList& aFrameList) {
 125     InsertFrames(aParent, aPrevSibling, aFrameList.FirstChild());
 126     aFrameList.mFirstChild = nsnull;
 127   }
 128
 129   PRBool Split(nsIFrame* aAfterFrame, nsIFrame** aNextFrameResult);
 130
 131   /**
 132    * Sort the frames according to content order so that the first
 133    * frame in the list is the first in content order. Frames for
 134    * the same content will be ordered so that a prev in flow
 135    * comes before its next in flow.
 136    */
 137   void SortByContentOrder();
 138
 139   nsIFrame* FirstChild() const {
 140     return mFirstChild;
 141   }
 142
 143   nsIFrame* LastChild() const;
 144
 145   nsIFrame* FrameAt(PRInt32 aIndex) const;
 146
 147   PRBool IsEmpty() const {
 148     return nsnull == mFirstChild;
 149   }
 150
 151   PRBool NotEmpty() const {
 152     return nsnull != mFirstChild;
 153   }
 154
 155   PRBool ContainsFrame(const nsIFrame* aFrame) const;
 156   PRBool ContainsFrameBefore(const nsIFrame* aFrame, const nsIFrame* aEnd) const;
 157
 158   PRInt32 GetLength() const;
 159
 160   nsIFrame* GetPrevSiblingFor(nsIFrame* aFrame) const;
 161
 162 #ifdef IBMBIDI
 163   /**
 164    * Return the frame before this frame in visual order (after Bidi reordering).
 165    * If aFrame is null, return the last frame in visual order.
 166    */
 167   nsIFrame* GetPrevVisualFor(nsIFrame* aFrame) const;
 168
 169   /**
 170    * Return the frame after this frame in visual order (after Bidi reordering).
 171    * If aFrame is null, return the first frame in visual order.
 172    */
 173   nsIFrame* GetNextVisualFor(nsIFrame* aFrame) const;
 174 #endif // IBMBIDI
 175
 176   void VerifyParent(nsIFrame* aParent) const;
 177
 178 #ifdef NS_DEBUG
 179   void List(FILE* out) const;
 180 #endif
 181
 182 private:
 183 #ifdef DEBUG
 184   void CheckForLoops();
 185 #endif
 186
 187 protected:
 188   nsIFrame* mFirstChild;
 189 };
 190
 191 #endif /* nsFrameList_h___ */