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Diffstat (limited to 'layout/svg/SVGClipPathFrame.h')
-rw-r--r-- | layout/svg/SVGClipPathFrame.h | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/layout/svg/SVGClipPathFrame.h b/layout/svg/SVGClipPathFrame.h new file mode 100644 index 0000000000..3ef5b11cca --- /dev/null +++ b/layout/svg/SVGClipPathFrame.h @@ -0,0 +1,170 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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 LAYOUT_SVG_SVGCLIPPATHFRAME_H_ +#define LAYOUT_SVG_SVGCLIPPATHFRAME_H_ + +#include "gfxMatrix.h" +#include "mozilla/Attributes.h" +#include "mozilla/SVGContainerFrame.h" + +class gfxContext; + +namespace mozilla { +class ISVGDisplayableFrame; +class PresShell; +} // namespace mozilla + +nsIFrame* NS_NewSVGClipPathFrame(mozilla::PresShell* aPresShell, + mozilla::ComputedStyle* aStyle); + +namespace mozilla { + +class SVGClipPathFrame final : public SVGContainerFrame { + friend nsIFrame* ::NS_NewSVGClipPathFrame(mozilla::PresShell* aPresShell, + ComputedStyle* aStyle); + + using Matrix = gfx::Matrix; + using SourceSurface = gfx::SourceSurface; + using imgDrawingParams = image::imgDrawingParams; + + protected: + explicit SVGClipPathFrame(ComputedStyle* aStyle, nsPresContext* aPresContext) + : SVGContainerFrame(aStyle, aPresContext, kClassID), + mIsBeingProcessed(false) { + AddStateBits(NS_FRAME_IS_NONDISPLAY); + } + + public: + NS_DECL_FRAMEARENA_HELPERS(SVGClipPathFrame) + + // nsIFrame methods: + void BuildDisplayList(nsDisplayListBuilder* aBuilder, + const nsDisplayListSet& aLists) override {} + + bool IsSVGTransformed(Matrix* aOwnTransforms, + Matrix* aFromParentTransforms) const override; + + // SVGClipPathFrame methods: + + /** + * Applies the clipPath by pushing a clip path onto the DrawTarget. + * + * This method must only be used if IsTrivial() returns true, otherwise use + * GetClipMask. + * + * @param aContext The context that the clip path is to be applied to. + * @param aClippedFrame The/an nsIFrame of the element that references this + * clipPath that is currently being processed. + * @param aMatrix The transform from aClippedFrame's user space to aContext's + * current transform. + */ + void ApplyClipPath(gfxContext& aContext, nsIFrame* aClippedFrame, + const gfxMatrix& aMatrix); + + /** + * Returns an alpha mask surface containing the clipping geometry. + * + * This method must only be used if IsTrivial() returns false, otherwise use + * ApplyClipPath. + * + * @param aReferenceContext Used to determine the backend for and size of the + * returned SourceSurface, the size being limited to the device space clip + * extents on the context. + * @param aClippedFrame The/an nsIFrame of the element that references this + * clipPath that is currently being processed. + * @param aMatrix The transform from aClippedFrame's user space to aContext's + * current transform. + * @param [in, optional] aExtraMask An extra surface that the returned + * surface should be masked with. + */ + already_AddRefed<SourceSurface> GetClipMask( + gfxContext& aReferenceContext, nsIFrame* aClippedFrame, + const gfxMatrix& aMatrix, SourceSurface* aExtraMask = nullptr); + + /** + * Paint mask directly onto a given context(aMaskContext). + * + * @param aMaskContext The target of mask been painting on. + * @param aClippedFrame The/an nsIFrame of the element that references this + * clipPath that is currently being processed. + * @param aMatrix The transform from aClippedFrame's user space to + * current transform. + * @param [in, optional] aExtraMask An extra surface that the returned + * surface should be masked with. + */ + void PaintClipMask(gfxContext& aMaskContext, nsIFrame* aClippedFrame, + const gfxMatrix& aMatrix, SourceSurface* aExtraMask); + + /** + * 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(ISVGDisplayableFrame** aSingleChild = nullptr); + + bool IsValid(); + + // nsIFrame interface: + nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute, + int32_t aModType) override; + + void Init(nsIContent* aContent, nsContainerFrame* aParent, + nsIFrame* aPrevInFlow) override; + +#ifdef DEBUG_FRAME_DUMP + nsresult GetFrameName(nsAString& aResult) const override { + return MakeFrameName(u"SVGClipPath"_ns, aResult); + } +#endif + + SVGBBox GetBBoxForClipPathFrame(const SVGBBox& aBBox, + const gfxMatrix& aMatrix, uint32_t aFlags); + + /** + * 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: + // SVGContainerFrame methods: + gfxMatrix GetCanvasTM() override; + + already_AddRefed<DrawTarget> CreateClipMask(gfxContext& aReferenceContext, + gfx::IntPoint& aOffset); + + void PaintFrameIntoMask(nsIFrame* aFrame, nsIFrame* aClippedFrame, + gfxContext& aTarget); + + // Set, during a GetClipMask() call, to the transform that still needs to be + // concatenated to the transform of the DrawTarget that was passed to + // GetClipMask in order to establish the coordinate space that the clipPath + // establishes for its contents (i.e. including applying 'clipPathUnits' and + // any 'transform' attribute set on the clipPath) specifically for clipping + // the frame that was passed to GetClipMask at that moment in time. This is + // set so that if our GetCanvasTM method is called while GetClipMask is + // painting its children, the returned matrix will include the transforms + // that should be used when creating the mask for the frame passed to + // GetClipMask. + // + // Note: The removal of GetCanvasTM is nearly complete, so our GetCanvasTM + // may not even be called soon/any more. + gfxMatrix mMatrixForChildren; + + // Flag used to indicate whether a methods that may reenter due to + // following a reference to another instance is currently executing. + bool mIsBeingProcessed; +}; + +} // namespace mozilla + +#endif // LAYOUT_SVG_SVGCLIPPATHFRAME_H_ |