layout/generic/nsHTMLContainerFrame.h

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  37
  38 /* base class #2 for rendering objects that have child lists */
  39
  40 #ifndef nsHTMLContainerFrame_h___
  41 #define nsHTMLContainerFrame_h___
  42
  43 #include "nsContainerFrame.h"
  44 #include "gfxPoint.h"
  45 class nsString;
  46 class nsAbsoluteFrame;
  47 class nsPlaceholderFrame;
  48 struct nsStyleDisplay;
  49 struct nsStylePosition;
  50 struct nsHTMLReflowMetrics;
  51 struct nsHTMLReflowState;
  52 class nsLineBox;
  53
  54 // Some macros for container classes to do sanity checking on
  55 // width/height/x/y values computed during reflow.
  56 #ifdef DEBUG
  57 #define CRAZY_W 500000
  58
  59 // 100000 lines, approximately. Assumes p2t is 15 and 15 pixels per line
  60 #define CRAZY_H 22500000
  61
  62 #define CRAZY_WIDTH(_x) (((_x) < -CRAZY_W) || ((_x) > CRAZY_W))
  63 #define CRAZY_HEIGHT(_y) (((_y) < -CRAZY_H) || ((_y) > CRAZY_H))
  64 #endif
  65
  66 class nsDisplayTextDecoration;
  67
  68 // Base class for html container frames that provides common
  69 // functionality.
  70 class nsHTMLContainerFrame : public nsContainerFrame {
  71 public:
  72
  73   /**
  74    * Helper method to create next-in-flows if necessary. If aFrame
  75    * already has a next-in-flow then this method does
  76    * nothing. Otherwise, a new continuation frame is created and
  77    * linked into the flow. In addition, the new frame becomes the
  78    * next-sibling of aFrame. If aPlaceholderResult is not null and
  79    * aFrame is a float or positioned, then *aPlaceholderResult holds
  80    * a placeholder.
  81    */
  82   static nsresult CreateNextInFlow(nsPresContext* aPresContext,
  83                                    nsIFrame*       aOuterFrame,
  84                                    nsIFrame*       aFrame,
  85                                    nsIFrame*&      aNextInFlowResult);
  86
  87   /**
  88    * Helper method to wrap views around frames. Used by containers
  89    * under special circumstances (can be used by leaf frames as well)
  90    * @param aContentParentFrame
  91    *         if non-null, this is the frame
  92    *         which would have held aFrame except that aFrame was reparented
  93    *         to an alternative geometric parent. This is necessary
  94    *         so that aFrame can remember to get its Z-order from
  95    *         aContentParentFrame.
  96    */
  97   static nsresult CreateViewForFrame(nsIFrame* aFrame,
  98                                      nsIFrame* aContentParentFrame,
  99                                      PRBool aForce);
 100
 101   static nsresult ReparentFrameView(nsPresContext* aPresContext,
 102                                     nsIFrame*       aChildFrame,
 103                                     nsIFrame*       aOldParentFrame,
 104                                     nsIFrame*       aNewParentFrame);
 105
 106   static nsresult ReparentFrameViewList(nsPresContext* aPresContext,
 107                                         nsIFrame*       aChildFrameList,
 108                                         nsIFrame*       aOldParentFrame,
 109                                         nsIFrame*       aNewParentFrame);
 110
 111   /**
 112    * Displays the standard border, background and outline for the frame
 113    * and calls DisplayTextDecorationsAndChildren. This is suitable for
 114    * inline frames or frames that behave like inlines.
 115    */
 116   NS_IMETHOD BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 117                               const nsRect&           aDirtyRect,
 118                               const nsDisplayListSet& aLists);
 119
 120   nsresult DisplayTextDecorations(nsDisplayListBuilder* aBuilder,
 121                                   nsDisplayList* aBelowTextDecorations,
 122                                   nsDisplayList* aAboveTextDecorations,
 123                                   nsLineBox* aLine);
 124
 125 protected:
 126   nsHTMLContainerFrame(nsStyleContext *aContext) : nsContainerFrame(aContext) {}
 127
 128   /**
 129    * Displays the below-children decorations, then the children, then
 130    * the above-children decorations, with the decorations going in the
 131    * Content() list. This is suitable for inline elements and elements
 132    * that behave like inline elements (e.g. MathML containers).
 133    */
 134   nsresult DisplayTextDecorationsAndChildren(nsDisplayListBuilder* aBuilder,
 135                                              const nsRect& aDirtyRect,
 136                                              const nsDisplayListSet& aLists);
 137
 138   /**
 139    * Fetch the text decorations for this frame.
 140    *  @param aIsBlock      whether |this| is a block frame or no.
 141    *  @param aDecorations  mask with all decorations.
 142    *                         See bug 1777 and 20163 to understand how a
 143    *                         frame can end up with several decorations.
 144    *  @param aUnderColor   The color of underline if the appropriate bit
 145    *                         in aDecoration is set. It is undefined otherwise.
 146    *  @param aOverColor    The color of overline if the appropriate bit
 147    *                         in aDecoration is set. It is undefined otherwise.
 148    *  @param aStrikeColor  The color of strike-through if the appropriate bit
 149    *                         in aDecoration is set. It is undefined otherwise.
 150    *  NOTE: This function assigns NS_STYLE_TEXT_DECORATION_NONE to
 151    *        aDecorations for text-less frames.  See bug 20163 for
 152    *        details.
 153    */
 154   void GetTextDecorations(nsPresContext* aPresContext,
 155                           PRBool aIsBlock,
 156                           PRUint8& aDecorations,
 157                           nscolor& aUnderColor,
 158                           nscolor& aOverColor,
 159                           nscolor& aStrikeColor);
 160
 161   /**
 162    * Function that does the actual drawing of the textdecoration.
 163    *   input:
 164    *    @param aCtx               the Thebes graphics context to draw on
 165    *    @param aLine              the line, or nsnull if this is an inline frame
 166    *    @param aColor             the color of the text-decoration
 167    *    @param aAscent            ascent of the font from which the
 168    *                                text-decoration was derived.
 169    *    @param aOffset            distance *above* baseline where the
 170    *                                text-decoration should be drawn,
 171    *                                i.e. negative offsets draws *below*
 172    *                                the baseline.
 173    *    @param aSize              the thickness of the line
 174    *    @param aDecoration        which line will be painted
 175    *                                i.e., NS_STYLE_TEXT_DECORATION_UNDERLINE or
 176    *                                      NS_STYLE_TEXT_DECORATION_OVERLINE or
 177    *                                      NS_STYLE_TEXT_DECORATION_LINE_THROUGH.
 178    */
 179   virtual void PaintTextDecorationLine(gfxContext* aCtx,
 180                                        const nsPoint& aPt,
 181                                        nsLineBox* aLine,
 182                                        nscolor aColor,
 183                                        gfxFloat aOffset,
 184                                        gfxFloat aAscent,
 185                                        gfxFloat aSize,
 186                                        const PRUint8 aDecoration);
 187
 188   friend class nsDisplayTextDecoration;
 189   friend class nsDisplayTextShadow;
 190 };
 191
 192 #endif /* nsHTMLContainerFrame_h___ */