gecko-dev/layout/generic/nsBlockBandData.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#ifndef nsBlockBandData_h___
#define nsBlockBandData_h___
#include "nsISpaceManager.h"
class nsIPresContext;
// Number of builtin nsBandTrapezoid's
#define NS_BLOCK_BAND_DATA_TRAPS 6
/**
* Class used to manage processing of the space-manager band data.
* Provides HTML/CSS specific behavior to the raw data.
*/
class nsBlockBandData : public nsBandData {
public:
nsBlockBandData();
~nsBlockBandData();
// Initialize. This must be called before any of the other methods.
nsresult Init(nsISpaceManager* aSpaceManager, const nsSize& aSpace);
// Get some available space. Note that aY is relative to the current
// space manager translation.
nsresult GetAvailableSpace(nscoord aY, nsRect& aResult);
// Clear any current floaters, returning a new Y coordinate
nscoord ClearFloaters(nscoord aY, PRUint8 aBreakType);
// Get the raw trapezoid count for this band.
PRInt32 GetTrapezoidCount() const {
return mCount;
}
const nsBandTrapezoid* GetTrapezoid(PRInt32 aIndex) const {
return &mTrapezoids[aIndex];
}
// Get the number of floaters that are impacting the current
// band. Note that this value is relative to the current translation
// in the space manager which means that some floaters may be hidden
// by the translation and therefore won't be in the count.
PRInt32 GetFloaterCount() const {
return mLeftFloaters + mRightFloaters;
}
PRInt32 GetLeftFloaterCount() const {
return mLeftFloaters;
}
PRInt32 GetRightFloaterCount() const {
return mRightFloaters;
}
// Return the impact on the max-element-size for this band by
// computing the maximum width and maximum height of all the
// floaters.
void GetMaxElementSize(nsIPresContext* aPresContext,
nscoord* aWidthResult, nscoord* aHeightResult) const;
// Utility method to save away the max-element-size associated with
// a floating frame.
static void StoreMaxElementSize(nsIPresContext* aPresContext,
nsIFrame* aFrame,
const nsSize& aMaxElementSize);
// Utility method to recover a stored max-element-size value
// associated with a floating frame.
static void RecoverMaxElementSize(nsIPresContext* aPresContext,
nsIFrame* aFrame,
nsSize* aResult);
protected:
/** utility method to calculate the band data at aY.
* nsBlockBandData methods should never call
* mSpaceManager->GetBandData directly.
* They should always call this method instead so data members
* mTrapezoid, mCount, and mSize all get managed properly.
*/
nsresult GetBandData(nscoord aY);
// The spacemanager we are getting space from
nsISpaceManager* mSpaceManager;
nscoord mSpaceManagerX, mSpaceManagerY;
// Limit to the available space (set by Init)
nsSize mSpace;
// Trapezoids used during band processing
nsBandTrapezoid mData[NS_BLOCK_BAND_DATA_TRAPS];
// Bounding rect of available space between any left and right floaters
nsRect mAvailSpace;
// Number of left/right floaters in the current band. Note that this
// number may be less than the total number of floaters present in
// the band, if our translation in the space manager "hides" some
// floaters.
PRInt32 mLeftFloaters, mRightFloaters;
void ComputeAvailSpaceRect();
PRBool ShouldClearFrame(nsIFrame* aFrame, PRUint8 aBreakType);
};
#endif /* nsBlockBandData_h___ */