gecko-dev/layout/generic/nsHTMLContainerFrame.h

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#ifndef nsHTMLContainerFrame_h___
#define nsHTMLContainerFrame_h___

#include "nsContainerFrame.h"
class nsString;
class nsAbsoluteFrame;
class nsPlaceholderFrame;
struct nsStyleDisplay;
struct nsStylePosition;
struct nsHTMLReflowMetrics;
struct nsHTMLReflowState;

// Some macros for container classes to do sanity checking on
// width/height/x/y values computed during reflow.
#ifdef DEBUG
#define CRAZY_W 500000

// 100000 lines, approximately. Assumes p2t is 15 and 15 pixels per line
#define CRAZY_H 22500000

#define CRAZY_WIDTH(_x) (((_x) < -CRAZY_W) || ((_x) > CRAZY_W))
#define CRAZY_HEIGHT(_y) (((_y) < -CRAZY_H) || ((_y) > CRAZY_H))
#endif

// Base class for html container frames that provides common
// functionality.
class nsHTMLContainerFrame : public nsContainerFrame {
public:
  NS_IMETHOD  Paint(nsPresContext*      aPresContext,
                    nsIRenderingContext& aRenderingContext,
                    const nsRect&        aDirtyRect,
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);

  /**
   * Helper method to create next-in-flows if necessary. If aFrame
   * already has a next-in-flow then this method does
   * nothing. Otherwise, a new continuation frame is created and
   * linked into the flow. In addition, the new frame becomes the
   * next-sibling of aFrame. If aPlaceholderResult is not null and
   * aFrame is a float or positioned, then *aPlaceholderResult holds
   * a placeholder.
   */
  static nsresult CreateNextInFlow(nsPresContext* aPresContext,
                                   nsIFrame*       aOuterFrame,
                                   nsIFrame*       aFrame,
                                   nsIFrame*&      aNextInFlowResult);

  /**
   * Helper method to wrap views around frames. Used by containers
   * under special circumstances (can be used by leaf frames as well)
   * @param aContentParentFrame
   *         if non-null, this is the frame 
   *         which would have held aFrame except that aFrame was reparented
   *         to an alternative geometric parent. This is necessary
   *         so that aFrame can remember to get its Z-order from 
   *         aContentParentFrame.
   */
  static nsresult CreateViewForFrame(nsIFrame* aFrame,
                                     nsIFrame* aContentParentFrame,
                                     PRBool aForce);

  static nsresult ReparentFrameView(nsPresContext* aPresContext,
                                    nsIFrame*       aChildFrame,
                                    nsIFrame*       aOldParentFrame,
                                    nsIFrame*       aNewParentFrame);

  static nsresult ReparentFrameViewList(nsPresContext* aPresContext,
                                        nsIFrame*       aChildFrameList,
                                        nsIFrame*       aOldParentFrame,
                                        nsIFrame*       aNewParentFrame);

protected:
  virtual PRIntn GetSkipSides() const = 0;

  void PaintSelf(nsPresContext*      aPresContext,
                 nsIRenderingContext& aRenderingContext,
                 const nsRect&        aDirtyRect) {
    nsContainerFrame::PaintSelf(aPresContext, aRenderingContext,
                                aDirtyRect, GetSkipSides());
  }

  /**
   * To be called *instead* of |PaintChildren| by frames that paint text
   * decorations (block and inline frames).  It will paint the
   * decorations before and after the call to PaintChildren.
   */
  void PaintDecorationsAndChildren(nsPresContext*      aPresContext,
                                   nsIRenderingContext& aRenderingContext,
                                   const nsRect&        aDirtyRect,
                                   nsFramePaintLayer    aWhichLayer,
                                   PRBool               aIsBlock,
                                   PRUint32             aFlags = 0);

  /**
   * Helper function to paint text decorations for this frame. This
   * function attempts to be general; hopefully particular frames can
   * get away with overriding PaintTextDecorationLines.  The function
   * should be called for one text-decoration at the time. This is so
   * line-through can be painted in front of children, while the other
   * decorations can be drawn behind.
   */
  void PaintTextDecorations(nsIRenderingContext& aRenderingContext,
                            nsIFontMetrics* aFontMetrics,
                            PRUint8 aDecoration,
                            nscolor aColor);

  /**
   * Fetch the text decorations for this frame. 
   *  @param aIsBlock      whether |this| is a block frame or no.
   *  @param aDecorations  mask with all decorations. 
   *                         See bug 1777 and 20163 to understand how a
   *                         frame can end up with several decorations.
   *  @param aUnderColor   The color of underline if the appropriate bit 
   *                         in aDecoration is set. It is undefined otherwise.
   *  @param aOverColor    The color of overline if the appropriate bit 
   *                         in aDecoration is set. It is undefined otherwise.
   *  @param aStrikeColor  The color of strike-through if the appropriate bit 
   *                         in aDecoration is set. It is undefined otherwise.
   *  NOTE: This function assigns NS_STYLE_TEXT_DECORATION_NONE to
   *        aDecorations for text-less frames.  See bug 20163 for
   *        details.
   */
  void GetTextDecorations(nsPresContext* aPresContext, 
                          PRBool aIsBlock,
                          PRUint8& aDecorations, 
                          nscolor& aUnderColor, 
                          nscolor& aOverColor, 
                          nscolor& aStrikeColor);

  /** 
   * Function that does the actual drawing of the textdecoration. 
   *   input:
   *    @param aRenderingContext.
   *    @param aColor             the color of the text-decoration
   *    @param aAscent            ascent of the font from which the
   *                                text-decoration was derived. 
   *    @param aOffset            distance *above* baseline where the
   *                                text-decoration should be drawn,
   *                                i.e. negative offsets draws *below*
   *                                the baseline.
   *    @param aSize              the thickness of the line
   */
  virtual void PaintTextDecorationLines(nsIRenderingContext& aRenderingContext,
                                        nscolor aColor,
                                        nscoord aOffset,
                                        nscoord aAscent,
                                        nscoord aSize);

};

#endif /* nsHTMLContainerFrame_h___ */