gecko-dev/layout/generic/nsAbsoluteContainingBlock.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
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*
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
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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 "nsLayoutAtoms.h"
class nsIAtom;
class nsIFrame;
class nsPresContext;
/**
* This class contains the logic for being an absolute containing block.
*
* There is no principal child list, just a named child list which contains
* the absolutely positioned frames
*
* All functions include as the first argument the frame that is delegating
* the request
*
* @see nsLayoutAtoms::absoluteList
*/
class nsAbsoluteContainingBlock
{
public:
nsAbsoluteContainingBlock() { } // useful for debugging
virtual ~nsAbsoluteContainingBlock() { } // useful for debugging
virtual nsIAtom* GetChildListName() const { return nsLayoutAtoms::absoluteList; }
nsresult FirstChild(const nsIFrame* aDelegatingFrame,
nsIAtom* aListName,
nsIFrame** aFirstChild) const;
nsIFrame* GetFirstChild() { return mAbsoluteFrames.FirstChild(); }
nsresult SetInitialChildList(nsIFrame* aDelegatingFrame,
nsIAtom* aListName,
nsIFrame* aChildList);
nsresult AppendFrames(nsIFrame* aDelegatingFrame,
nsIAtom* aListName,
nsIFrame* aFrameList);
nsresult InsertFrames(nsIFrame* aDelegatingFrame,
nsIAtom* aListName,
nsIFrame* aPrevFrame,
nsIFrame* aFrameList);
nsresult RemoveFrame(nsIFrame* aDelegatingFrame,
nsIAtom* aListName,
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.
// If aChildBounds is set, it returns (in the local coordinate space) the
// bounding rect of the absolutely positioned child elements taking into
// account their overflow area (if it is visible).
// @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(nsIFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
nsRect* aChildBounds = nsnull,
PRBool aForceReflow = PR_TRUE,
PRBool aCBWidthChanged = PR_TRUE,
PRBool aCBHeightChanged = PR_TRUE);
// Called by the delegating frame to determine whether the
// incremental reflow is entirely targeted at absolute children
PRBool ReflowingAbsolutesOnly(nsIFrame* aDelegatingFrame,
const nsHTMLReflowState& aReflowState);
// Called only for a reflow reason of eReflowReason_Incremental.
void IncrementalReflow(nsIFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight);
void DestroyFrames(nsIFrame* aDelegatingFrame);
PRBool HasAbsoluteFrames() {return mAbsoluteFrames.NotEmpty();}
void CalculateChildBounds(nsPresContext* aPresContext, nsRect& aChildBounds);
protected:
// Returns PR_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.
PRBool FrameDependsOnContainer(nsIFrame* f, PRBool aCBWidthChanged,
PRBool aCBHeightChanged);
nsresult ReflowAbsoluteFrame(nsIFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
nsIFrame* aKidFrame,
nsReflowReason aReason,
nsReflowStatus& aStatus);
protected:
nsFrameList mAbsoluteFrames; // additional named child list
#ifdef DEBUG
// helper routine for debug printout
void PrettyUC(nscoord aSize,
char* aBuf);
#endif
};
#endif /* nsnsAbsoluteContainingBlock_h___ */