gecko-dev/layout/generic/nsBlockReflowContext.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
// vim:cindent:ts=2:et:sw=2:
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 * The Original Code is Mozilla Communicator client code.
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#ifndef nsBlockReflowContext_h___
#define nsBlockReflowContext_h___

#include "nsIFrame.h"
#include "nsHTMLReflowState.h"
#include "nsHTMLReflowMetrics.h"

class nsBlockFrame;
class nsIFrame;
class nsIPresContext;
class nsLineLayout;
struct nsStylePosition;
struct nsBlockHorizontalAlign;

/**
 * An encapsulation of the state and algorithm for reflowing block frames.
 */
class nsBlockReflowContext {
public:
  nsBlockReflowContext(nsIPresContext* aPresContext,
                       const nsHTMLReflowState& aParentRS,
                       PRBool aComputeMaxElementSize,
                       PRBool aComputeMaximumWidth);
  ~nsBlockReflowContext() { }

  void SetNextRCFrame(nsIFrame* aNextRCFrame) {
    mNextRCFrame = aNextRCFrame;
  }

  nsIFrame* GetNextRCFrame() const {
    return mNextRCFrame;
  }

  nsresult ReflowBlock(nsIFrame* aFrame,
                       const nsRect& aSpace,
                       PRBool aApplyTopMargin,
                       nsCollapsingMargin& aPrevBottomMargin,
                       PRBool aIsAdjacentWithTop,
                       nsMargin& aComputedOffsets,
                       nsReflowStatus& aReflowStatus);

  PRBool PlaceBlock(const nsHTMLReflowState& aReflowState,
                    PRBool                   aForceFit,
                    const nsMargin&          aComputedOffsets,
                    nsCollapsingMargin&      aBottomMarginResult /* out */,
                    nsRect&                  aInFlowBounds,
                    nsRect&                  aCombinedRect);

  void AlignBlockHorizontally(nscoord aWidth, nsBlockHorizontalAlign&);

  nsCollapsingMargin& GetCarriedOutBottomMargin() {
    return mMetrics.mCarriedOutBottomMargin;
  }

  nscoord GetTopMargin() const {
    return mTopMargin;
  }

  const nsMargin& GetMargin() const {
    return mMargin;
  }

  const nsHTMLReflowMetrics& GetMetrics() const {
    return mMetrics;
  }

  const nsSize& GetMaxElementSize() const {
    return mMaxElementSize;
  }
  
  nscoord GetMaximumWidth() const {
    return mMetrics.mMaximumWidth;
  }

  PRBool BlockShouldInvalidateItself() const {
    return mBlockShouldInvalidateItself;
  }

  static void ComputeCollapsedTopMargin(nsIPresContext* aPresContext,
                                        nsHTMLReflowState& aRS,
                           /* inout */  nsCollapsingMargin& aMargin);

protected:
  nsStyleUnit GetRealMarginLeftUnit();
  nsStyleUnit GetRealMarginRightUnit();

  nsresult DoReflowBlock(nsHTMLReflowState &aReflowState,
                         nsReflowReason aReason,
                         nsIFrame* aFrame,
                         const nsRect& aSpace,
                         PRBool aApplyTopMargin,
                         nsCollapsingMargin& aPrevBottomMargin,
                         PRBool aIsAdjacentWithTop,
                         nsMargin& aComputedOffsets,
                         nsReflowStatus& aReflowStatus);

  nsIPresContext* mPresContext;
  const nsHTMLReflowState& mOuterReflowState;

  nsIFrame* mFrame;
  nsRect mSpace;

  // For an incremental reflow that has not yet reached the target
  // frame, this field contains the next frame along the reflow's
  // path.
  nsIFrame* mNextRCFrame;

  // Spacing style for the frame we are reflowing; only valid after reflow
  const nsStyleBorder* mStyleBorder;
  const nsStyleMargin* mStyleMargin;
  const nsStylePadding* mStylePadding;

  nscoord mComputedWidth;               // copy of reflowstate's computedWidth
  nsMargin mMargin;
  nscoord mX, mY;
  nsHTMLReflowMetrics mMetrics;
  nscoord mTopMargin;
  nsSize mMaxElementSize;
  PRPackedBool mIsTable;
  PRPackedBool mComputeMaximumWidth;
  PRPackedBool mBlockShouldInvalidateItself;
};

#endif /* nsBlockReflowContext_h___ */