gecko-dev/layout/svg/nsSVGClipPathFrame.h

134 lines
4.3 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/. */
#ifndef __NS_SVGCLIPPATHFRAME_H__
#define __NS_SVGCLIPPATHFRAME_H__
#include "mozilla/Attributes.h"
#include "gfxMatrix.h"
#include "nsSVGContainerFrame.h"
#include "nsSVGUtils.h"
class gfxContext;
class nsISVGChildFrame;
typedef nsSVGContainerFrame nsSVGClipPathFrameBase;
class nsSVGClipPathFrame : public nsSVGClipPathFrameBase
{
friend nsIFrame*
NS_NewSVGClipPathFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
protected:
explicit nsSVGClipPathFrame(nsStyleContext* aContext)
: nsSVGClipPathFrameBase(aContext)
, mInUse(false)
{
AddStateBits(NS_FRAME_IS_NONDISPLAY);
}
public:
NS_DECL_FRAMEARENA_HELPERS
// nsIFrame methods:
virtual void BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists) override {}
// nsSVGClipPathFrame methods:
/**
* If the SVG clipPath is simple (as determined by the IsTrivial() method),
* calling this method simply pushes a clip path onto the DrawTarget. If the
* SVG clipPath is not simple then calling this method will paint the
* clipPath's contents (geometry being filled only, with opaque black) to the
* DrawTarget. In this latter case callers are expected to first push a
* group before calling this method, then pop the group after calling and use
* it as a mask to mask the clipped frame.
*
* XXXjwatt Maybe split this into two methods.
*/
nsresult ApplyClipOrPaintClipMask(gfxContext& aContext,
nsIFrame* aClippedFrame,
const gfxMatrix &aMatrix);
/**
* aPoint is expected to be in aClippedFrame's SVG user space.
*/
bool PointIsInsideClipPath(nsIFrame* aClippedFrame, const gfxPoint &aPoint);
// Check if this clipPath is made up of more than one geometry object.
// If so, the clipping API in cairo isn't enough and we need to use
// mask based clipping.
bool IsTrivial(nsISVGChildFrame **aSingleChild = nullptr);
bool IsValid();
// nsIFrame interface:
virtual nsresult AttributeChanged(int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType) override;
virtual void Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) override;
/**
* Get the "type" of the frame
*
* @see nsGkAtoms::svgClipPathFrame
*/
virtual nsIAtom* GetType() const override;
#ifdef DEBUG_FRAME_DUMP
virtual nsresult GetFrameName(nsAString& aResult) const override
{
return MakeFrameName(NS_LITERAL_STRING("SVGClipPath"), aResult);
}
#endif
SVGBBox
GetBBoxForClipPathFrame(const SVGBBox &aBBox, const gfxMatrix &aMatrix);
/**
* If the clipPath element transforms its children due to
* clipPathUnits="objectBoundingBox" being set on it and/or due to the
* 'transform' attribute being set on it, this function returns the resulting
* transform.
*/
gfxMatrix GetClipPathTransform(nsIFrame* aClippedFrame);
private:
// A helper class to allow us to paint clip paths safely. The helper
// automatically sets and clears the mInUse flag on the clip path frame
// (to prevent nasty reference loops). It's easy to mess this up
// and break things, so this helper makes the code far more robust.
class MOZ_RAII AutoClipPathReferencer
{
public:
explicit AutoClipPathReferencer(nsSVGClipPathFrame *aFrame
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mFrame(aFrame) {
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
NS_ASSERTION(!mFrame->mInUse, "reference loop!");
mFrame->mInUse = true;
}
~AutoClipPathReferencer() {
mFrame->mInUse = false;
}
private:
nsSVGClipPathFrame *mFrame;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
gfxMatrix mMatrixForChildren;
// recursion prevention flag
bool mInUse;
// nsSVGContainerFrame methods:
virtual gfxMatrix GetCanvasTM() override;
};
#endif