gecko/layout/generic/nsCanvasFrame.h

188 lines
6.1 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* rendering object that goes directly inside the document's scrollbars */
#ifndef nsCanvasFrame_h___
#define nsCanvasFrame_h___
#include "nsContainerFrame.h"
#include "nsIScrollPositionListener.h"
#include "nsDisplayList.h"
#include "nsGkAtoms.h"
class nsPresContext;
class nsRenderingContext;
class nsEvent;
/**
* Root frame class.
*
* The root frame is the parent frame for the document element's frame.
* It only supports having a single child frame which must be an area
* frame
*/
class nsCanvasFrame : public nsContainerFrame,
public nsIScrollPositionListener
{
public:
nsCanvasFrame(nsStyleContext* aContext)
: nsContainerFrame(aContext),
mDoPaintFocus(false),
mAddedScrollPositionListener(false) {}
NS_DECL_QUERYFRAME_TARGET(nsCanvasFrame)
NS_DECL_QUERYFRAME
NS_DECL_FRAMEARENA_HELPERS
virtual void DestroyFrom(nsIFrame* aDestructRoot);
NS_IMETHOD SetInitialChildList(ChildListID aListID,
nsFrameList& aChildList);
NS_IMETHOD AppendFrames(ChildListID aListID,
nsFrameList& aFrameList);
NS_IMETHOD InsertFrames(ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList);
NS_IMETHOD RemoveFrame(ChildListID aListID,
nsIFrame* aOldFrame);
virtual nscoord GetMinWidth(nsRenderingContext *aRenderingContext);
virtual nscoord GetPrefWidth(nsRenderingContext *aRenderingContext);
NS_IMETHOD Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus);
virtual bool IsFrameOfType(PRUint32 aFlags) const
{
return nsContainerFrame::IsFrameOfType(aFlags &
~(nsIFrame::eCanContainOverflowContainers));
}
/** SetHasFocus tells the CanvasFrame to draw with focus ring
* @param aHasFocus true to show focus ring, false to hide it
*/
NS_IMETHOD SetHasFocus(bool aHasFocus);
NS_IMETHOD BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists);
void PaintFocus(nsRenderingContext& aRenderingContext, nsPoint aPt);
// nsIScrollPositionListener
virtual void ScrollPositionWillChange(nscoord aX, nscoord aY);
virtual void ScrollPositionDidChange(nscoord aX, nscoord aY) {}
/**
* Get the "type" of the frame
*
* @see nsGkAtoms::canvasFrame
*/
virtual nsIAtom* GetType() const;
virtual nsresult StealFrame(nsPresContext* aPresContext,
nsIFrame* aChild,
bool aForceNormal)
{
NS_ASSERTION(!aForceNormal, "No-one should be passing this in here");
// nsCanvasFrame keeps overflow container continuations of its child
// frame in main child list
nsresult rv = nsContainerFrame::StealFrame(aPresContext, aChild, true);
if (NS_FAILED(rv)) {
rv = nsContainerFrame::StealFrame(aPresContext, aChild);
}
return rv;
}
#ifdef DEBUG
NS_IMETHOD GetFrameName(nsAString& aResult) const;
#endif
NS_IMETHOD GetContentForEvent(nsEvent* aEvent,
nsIContent** aContent);
nsRect CanvasArea() const;
protected:
virtual int GetSkipSides() const;
// Data members
bool mDoPaintFocus;
bool mAddedScrollPositionListener;
};
/**
* Override nsDisplayBackground methods so that we pass aBGClipRect to
* PaintBackground, covering the whole overflow area.
* We can also paint an "extra background color" behind the normal
* background.
*/
class nsDisplayCanvasBackground : public nsDisplayBackground {
public:
nsDisplayCanvasBackground(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame)
: nsDisplayBackground(aBuilder, aFrame)
{
mExtraBackgroundColor = NS_RGBA(0,0,0,0);
}
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion)
{
return NS_GET_A(mExtraBackgroundColor) > 0 ||
nsDisplayBackground::ComputeVisibility(aBuilder, aVisibleRegion,
aAllowVisibleRegionExpansion);
}
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap)
{
if (NS_GET_A(mExtraBackgroundColor) == 255) {
return nsRegion(GetBounds(aBuilder, aSnap));
}
return nsDisplayBackground::GetOpaqueRegion(aBuilder, aSnap);
}
virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor)
{
nscolor background;
if (!nsDisplayBackground::IsUniform(aBuilder, &background))
return false;
NS_ASSERTION(background == NS_RGBA(0,0,0,0),
"The nsDisplayBackground for a canvas frame doesn't paint "
"its background color normally");
*aColor = mExtraBackgroundColor;
return true;
}
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
{
nsCanvasFrame* frame = static_cast<nsCanvasFrame*>(mFrame);
*aSnap = true;
return frame->CanvasArea() + ToReferenceFrame();
}
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames)
{
// We need to override so we don't consider border-radius.
aOutFrames->AppendElement(mFrame);
}
virtual void Paint(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx);
void SetExtraBackgroundColor(nscolor aColor)
{
mExtraBackgroundColor = aColor;
}
NS_DISPLAY_DECL_NAME("CanvasBackground", TYPE_CANVAS_BACKGROUND)
private:
nscolor mExtraBackgroundColor;
};
#endif /* nsCanvasFrame_h___ */