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 #include "nsIDeviceContext.h"
  46
  47 class nsString;
  48 class nsAbsoluteFrame;
  49 class nsPlaceholderFrame;
  50 struct nsStyleDisplay;
  51 struct nsStylePosition;
  52 struct nsHTMLReflowMetrics;
  53 struct nsHTMLReflowState;
  54 class nsLineBox;
  55
  56 // Some macros for container classes to do sanity checking on
  57 // width/height/x/y values computed during reflow.
  58 #ifdef DEBUG
  59 #define CRAZY_W (1000000*nsIDeviceContext::AppUnitsPerCSSPixel())
  60 #define CRAZY_H CRAZY_W
  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   NS_DECL_FRAMEARENA_HELPERS
  73
  74   /**
  75    * Helper method to wrap views around frames. Used by containers
  76    * under special circumstances (can be used by leaf frames as well)
  77    */
  78   static nsresult CreateViewForFrame(nsIFrame* aFrame,
  79                                      PRBool aForce);
  80
  81   static nsresult ReparentFrameView(nsPresContext* aPresContext,
  82                                     nsIFrame*       aChildFrame,
  83                                     nsIFrame*       aOldParentFrame,
  84                                     nsIFrame*       aNewParentFrame);
  85
  86   static nsresult ReparentFrameViewList(nsPresContext*     aPresContext,
  87                                         const nsFrameList& aChildFrameList,
  88                                         nsIFrame*          aOldParentFrame,
  89                                         nsIFrame*          aNewParentFrame);
  90
  91   /**
  92    * Helper method to create next-in-flows if necessary. If aFrame
  93    * already has a next-in-flow then this method does
  94    * nothing. Otherwise, a new continuation frame is created and
  95    * linked into the flow. In addition, the new frame is inserted
  96    * into the principal child list after aFrame.
  97    * @note calling this method on a block frame is illegal. Use
  98    * nsBlockFrame::CreateContinuationFor() instead.
  99    * @param aNextInFlowResult will contain the next-in-flow
 100    *        <b>if and only if</b> one is created. If a next-in-flow already
 101    *        exists aNextInFlowResult is set to nsnull.
 102    * @return NS_OK if a next-in-flow already exists or is successfully created.
 103    */
 104   nsresult CreateNextInFlow(nsPresContext* aPresContext,
 105                             nsIFrame*       aFrame,
 106                             nsIFrame*&      aNextInFlowResult);
 107
 108   /**
 109    * Displays the standard border, background and outline for the frame
 110    * and calls DisplayTextDecorationsAndChildren. This is suitable for
 111    * inline frames or frames that behave like inlines.
 112    */
 113   NS_IMETHOD BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 114                               const nsRect&           aDirtyRect,
 115                               const nsDisplayListSet& aLists);
 116
 117   nsresult DisplayTextDecorations(nsDisplayListBuilder* aBuilder,
 118                                   nsDisplayList* aBelowTextDecorations,
 119                                   nsDisplayList* aAboveTextDecorations,
 120                                   nsLineBox* aLine);
 121
 122 protected:
 123   nsHTMLContainerFrame(nsStyleContext *aContext) : nsContainerFrame(aContext) {}
 124
 125   /**
 126    * Displays the below-children decorations, then the children, then
 127    * the above-children decorations, with the decorations going in the
 128    * Content() list. This is suitable for inline elements and elements
 129    * that behave like inline elements (e.g. MathML containers).
 130    */
 131   nsresult DisplayTextDecorationsAndChildren(nsDisplayListBuilder* aBuilder,
 132                                              const nsRect& aDirtyRect,
 133                                              const nsDisplayListSet& aLists);
 134
 135   /**
 136    * Fetch the text decorations for this frame.
 137    *  @param aIsBlock      whether |this| is a block frame or no.
 138    *  @param aDecorations  mask with all decorations.
 139    *                         See bug 1777 and 20163 to understand how a
 140    *                         frame can end up with several decorations.
 141    *  @param aUnderColor   The color of underline if the appropriate bit
 142    *                         in aDecoration is set. It is undefined otherwise.
 143    *  @param aOverColor    The color of overline if the appropriate bit
 144    *                         in aDecoration is set. It is undefined otherwise.
 145    *  @param aStrikeColor  The color of strike-through if the appropriate bit
 146    *                         in aDecoration is set. It is undefined otherwise.
 147    *  NOTE: This function assigns NS_STYLE_TEXT_DECORATION_NONE to
 148    *        aDecorations for text-less frames.  See bug 20163 for
 149    *        details.
 150    */
 151   void GetTextDecorations(nsPresContext* aPresContext,
 152                           PRBool aIsBlock,
 153                           PRUint8& aDecorations,
 154                           nscolor& aUnderColor,
 155                           nscolor& aOverColor,
 156                           nscolor& aStrikeColor);
 157
 158   /**
 159    * Function that does the actual drawing of the textdecoration.
 160    *   input:
 161    *    @param aCtx               the Thebes graphics context to draw on
 162    *    @param aLine              the line, or nsnull if this is an inline frame
 163    *    @param aColor             the color of the text-decoration
 164    *    @param aAscent            ascent of the font from which the
 165    *                                text-decoration was derived.
 166    *    @param aOffset            distance *above* baseline where the
 167    *                                text-decoration should be drawn,
 168    *                                i.e. negative offsets draws *below*
 169    *                                the baseline.
 170    *    @param aSize              the thickness of the line
 171    *    @param aDecoration        which line will be painted
 172    *                                i.e., NS_STYLE_TEXT_DECORATION_UNDERLINE or
 173    *                                      NS_STYLE_TEXT_DECORATION_OVERLINE or
 174    *                                      NS_STYLE_TEXT_DECORATION_LINE_THROUGH.
 175    */
 176   virtual void PaintTextDecorationLine(gfxContext* aCtx,
 177                                        const nsPoint& aPt,
 178                                        nsLineBox* aLine,
 179                                        nscolor aColor,
 180                                        gfxFloat aOffset,
 181                                        gfxFloat aAscent,
 182                                        gfxFloat aSize,
 183                                        const PRUint8 aDecoration);
 184
 185   virtual void AdjustForTextIndent(const nsLineBox* aLine,
 186                                    nscoord& start,
 187                                    nscoord& width);
 188
 189   friend class nsDisplayTextDecoration;
 190   friend class nsDisplayTextShadow;
 191 };
 192
 193 #endif /* nsHTMLContainerFrame_h___ */