nsAbsoluteContainingBlock.h
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/*
* code for managing absolutely positioned children of a rendering
* object that is a containing block for them
*/
#ifndef nsAbsoluteContainingBlock_h___
#define nsAbsoluteContainingBlock_h___
#include "nsFrameList.h"
#include "nsHTMLReflowState.h"
#include "nsGkAtoms.h"
#include "nsContainerFrame.h"
class nsIAtom;
class nsIFrame;
class nsPresContext;
/**
* This class contains the logic for being an absolute containing block. This
* class is used within viewport frames (for frames representing content with
* fixed position) and blocks (for frames representing absolutely positioned
* content), since each set of frames is absolutely positioned with respect to
* its parent.
*
* There is no principal child list, just a named child list which contains
* the absolutely positioned frames (kAbsoluteList or kFixedList).
*
* All functions include as the first argument the frame that is delegating
* the request.
*
*/
class nsAbsoluteContainingBlock
{
public:
typedef nsIFrame::ChildListID ChildListID;
nsAbsoluteContainingBlock(ChildListID aChildListID)
#ifdef DEBUG
: mChildListID(aChildListID)
#endif
{
NS_ASSERTION(mChildListID == nsIFrame::kAbsoluteList ||
mChildListID == nsIFrame::kFixedList,
"should either represent position:fixed or absolute content");
}
#ifdef DEBUG
ChildListID GetChildListID() const { return mChildListID; }
#endif
const nsFrameList& GetChildList() const { return mAbsoluteFrames; }
void AppendChildList(nsTArray<nsIFrame::ChildList>* aLists,
ChildListID aListID) const
{
NS_ASSERTION(aListID == GetChildListID(), "wrong list ID");
GetChildList().AppendIfNonempty(aLists, aListID);
}
nsresult SetInitialChildList(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsFrameList& aChildList);
nsresult AppendFrames(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsFrameList& aFrameList);
nsresult InsertFrames(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList);
void RemoveFrame(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsIFrame* aOldFrame);
// Called by the delegating frame after it has done its reflow first. This
// function will reflow any absolutely positioned child frames that need to
// be reflowed, e.g., because the absolutely positioned child frame has
// 'auto' for an offset, or a percentage based width or height.
// aOverflowAreas, if non-null, is unioned with (in the local
// coordinate space) the overflow areas of the absolutely positioned
// children.
// @param aForceReflow if this is false, reflow for some absolutely
// positioned frames may be skipped based on whether they use
// placeholders for positioning and on whether the containing block
// width or height changed.
nsresult Reflow(nsContainerFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aReflowStatus,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
bool aConstrainHeight,
bool aCBWidthChanged,
bool aCBHeightChanged,
nsOverflowAreas* aOverflowAreas);
void DestroyFrames(nsIFrame* aDelegatingFrame,
nsIFrame* aDestructRoot);
bool HasAbsoluteFrames() {return mAbsoluteFrames.NotEmpty();}
// Mark our size-dependent absolute frames with NS_FRAME_HAS_DIRTY_CHILDREN
// so that we'll make sure to reflow them.
void MarkSizeDependentFramesDirty();
// Mark all our absolute frames with NS_FRAME_IS_DIRTY
void MarkAllFramesDirty();
protected:
// Returns true if the position of f depends on the position of
// its placeholder or if the position or size of f depends on a
// containing block dimension that changed.
bool FrameDependsOnContainer(nsIFrame* f, bool aCBWidthChanged,
bool aCBHeightChanged);
nsresult ReflowAbsoluteFrame(nsIFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
bool aConstrainHeight,
nsIFrame* aKidFrame,
nsReflowStatus& aStatus,
nsOverflowAreas* aOverflowAreas);
// Mark our absolute frames dirty. If aMarkAllDirty is true, all will be
// marked with NS_FRAME_IS_DIRTY. Otherwise, the size-dependant ones will be
// marked with NS_FRAME_HAS_DIRTY_CHILDREN.
void DoMarkFramesDirty(bool aMarkAllDirty);
protected:
nsFrameList mAbsoluteFrames; // additional named child list
#ifdef DEBUG
ChildListID const mChildListID; // kFixedList or kAbsoluteList
// helper routine for debug printout
void PrettyUC(nscoord aSize,
char* aBuf);
#endif
};
#endif /* nsnsAbsoluteContainingBlock_h___ */
