pjs/layout/generic/nsBlockReflowContext.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
// vim:cindent:ts=2:et:sw=2:
/* ***** BEGIN LICENSE BLOCK *****
* 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
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* 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 Communicator client 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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* ***** END LICENSE BLOCK ***** */
/* class that a parent frame uses to reflow a block frame */
#ifndef nsBlockReflowContext_h___
#define nsBlockReflowContext_h___
#include "nsIFrame.h"
#include "nsHTMLReflowMetrics.h"
class nsBlockFrame;
class nsBlockReflowState;
struct nsHTMLReflowState;
class nsLineBox;
class nsIFrame;
class nsPresContext;
class nsLineLayout;
struct nsStylePosition;
struct nsBlockHorizontalAlign;
/**
* An encapsulation of the state and algorithm for reflowing block frames.
*/
class nsBlockReflowContext {
public:
nsBlockReflowContext(nsPresContext* aPresContext,
const nsHTMLReflowState& aParentRS);
~nsBlockReflowContext() { }
nsresult ReflowBlock(const nsRect& aSpace,
PRBool aApplyTopMargin,
nsCollapsingMargin& aPrevMargin,
nscoord aClearance,
PRBool aIsAdjacentWithTop,
nsLineBox* aLine,
nsHTMLReflowState& aReflowState,
nsReflowStatus& aReflowStatus,
nsBlockReflowState& aState);
PRBool PlaceBlock(const nsHTMLReflowState& aReflowState,
PRBool aForceFit,
nsLineBox* aLine,
nsCollapsingMargin& aBottomMarginResult /* out */,
nsRect& aInFlowBounds,
nsRect& aCombinedRect,
nsReflowStatus aReflowStatus);
nsCollapsingMargin& GetCarriedOutBottomMargin() {
return mMetrics.mCarriedOutBottomMargin;
}
nscoord GetTopMargin() const {
return mTopMargin.get();
}
const nsHTMLReflowMetrics& GetMetrics() const {
return mMetrics;
}
/**
* Computes the collapsed top margin for a block whose reflow state is in aRS.
* The computed margin is added into aMargin.
* If aClearanceFrame is null then this is the first optimistic pass which shall assume
* that no frames have clearance, and we clear the HasClearance on all frames encountered.
* If non-null, this is the second pass and
* the caller has decided aClearanceFrame needs clearance (and we will
* therefore stop collapsing there); also, this function is responsible for marking
* it with SetHasClearance.
* If in the optimistic pass any frame is encountered that might possibly need
* clearance (i.e., if we really needed the optimism assumption) then we set aMayNeedRetry
* to true.
* We return PR_TRUE if we changed the clearance state of any line and marked it dirty.
*/
static PRBool ComputeCollapsedTopMargin(const nsHTMLReflowState& aRS,
nsCollapsingMargin* aMargin, nsIFrame* aClearanceFrame,
PRBool* aMayNeedRetry, PRBool* aIsEmpty = nsnull);
protected:
nsPresContext* mPresContext;
const nsHTMLReflowState& mOuterReflowState;
nsIFrame* mFrame;
nsRect mSpace;
nscoord mX, mY;
nsHTMLReflowMetrics mMetrics;
nsCollapsingMargin mTopMargin;
};
#endif /* nsBlockReflowContext_h___ */