gecko-dev/layout/generic/nsLeafFrame.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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*
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* 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.
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*
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/* base class for rendering objects that do not have child lists */
#ifndef nsLeafFrame_h___
#define nsLeafFrame_h___
#include "nsFrame.h"
#include "nsDisplayList.h"
/**
* Abstract class that provides simple fixed-size layout for leaf objects
* (e.g. images, form elements, etc.). Deriviations provide the implementation
* of the GetDesiredSize method. The rendering method knows how to render
* borders and backgrounds.
*/
class nsLeafFrame : public nsFrame {
public:
NS_DECL_FRAMEARENA_HELPERS
// nsIFrame replacements
NS_IMETHOD BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists) {
DO_GLOBAL_REFLOW_COUNT_DSP("nsLeafFrame");
return DisplayBorderBackgroundOutline(aBuilder, aLists);
}
/**
* Both GetMinWidth and GetPrefWidth will return whatever GetIntrinsicWidth
* returns.
*/
virtual nscoord GetMinWidth(nsRenderingContext *aRenderingContext);
virtual nscoord GetPrefWidth(nsRenderingContext *aRenderingContext);
/**
* Our auto size is just intrinsic width and intrinsic height.
*/
virtual nsSize ComputeAutoSize(nsRenderingContext *aRenderingContext,
nsSize aCBSize, nscoord aAvailableWidth,
nsSize aMargin, nsSize aBorder,
nsSize aPadding, PRBool aShrinkWrap);
/**
* Reflow our frame. This will use the computed width plus borderpadding for
* the desired width, and use the return value of GetIntrinsicHeight plus
* borderpadding for the desired height. Ascent will be set to the height,
* and descent will be set to 0.
*/
NS_IMETHOD Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus);
/**
* This method does most of the work that Reflow() above need done.
*/
NS_IMETHOD DoReflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus);
virtual PRBool IsFrameOfType(PRUint32 aFlags) const
{
// We don't actually contain a block, but we do always want a
// computed width, so tell a little white lie here.
return nsFrame::IsFrameOfType(aFlags & ~(nsIFrame::eReplacedContainsBlock));
}
protected:
nsLeafFrame(nsStyleContext* aContext) : nsFrame(aContext) {}
virtual ~nsLeafFrame();
/**
* Return the intrinsic width of the frame's content area. Note that this
* should not include borders or padding and should not depend on the applied
* styles.
*/
virtual nscoord GetIntrinsicWidth() = 0;
/**
* Return the intrinsic height of the frame's content area. This should not
* include border or padding. This will only matter if the specified height
* is auto. Note that subclasses must either implement this or override
* Reflow and ComputeAutoSize; the default Reflow and ComputeAutoSize impls
* call this method.
*/
virtual nscoord GetIntrinsicHeight();
/**
* Subroutine to add in borders and padding
*/
void AddBordersAndPadding(const nsHTMLReflowState& aReflowState,
nsHTMLReflowMetrics& aDesiredSize);
/**
* Set aDesiredSize to be the available size
*/
void SizeToAvailSize(const nsHTMLReflowState& aReflowState,
nsHTMLReflowMetrics& aDesiredSize);
};
#endif /* nsLeafFrame_h___ */