1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef LAYOUT_SVG_SVGCLIPPATHFRAME_H_ 8 #define LAYOUT_SVG_SVGCLIPPATHFRAME_H_ 9 10 #include "gfxMatrix.h" 11 #include "mozilla/Attributes.h" 12 #include "mozilla/SVGContainerFrame.h" 13 14 class gfxContext; 15 16 namespace mozilla { 17 class ISVGDisplayableFrame; 18 class PresShell; 19 } // namespace mozilla 20 21 nsIFrame* NS_NewSVGClipPathFrame(mozilla::PresShell* aPresShell, 22 mozilla::ComputedStyle* aStyle); 23 24 namespace mozilla { 25 26 class SVGClipPathFrame final : public SVGContainerFrame { 27 friend nsIFrame* ::NS_NewSVGClipPathFrame(mozilla::PresShell* aPresShell, 28 ComputedStyle* aStyle); 29 30 using Matrix = gfx::Matrix; 31 using SourceSurface = gfx::SourceSurface; 32 using imgDrawingParams = image::imgDrawingParams; 33 34 protected: SVGClipPathFrame(ComputedStyle * aStyle,nsPresContext * aPresContext)35 explicit SVGClipPathFrame(ComputedStyle* aStyle, nsPresContext* aPresContext) 36 : SVGContainerFrame(aStyle, aPresContext, kClassID), 37 mIsBeingProcessed(false) { 38 AddStateBits(NS_FRAME_IS_NONDISPLAY); 39 } 40 41 public: NS_DECL_FRAMEARENA_HELPERS(SVGClipPathFrame)42 NS_DECL_FRAMEARENA_HELPERS(SVGClipPathFrame) 43 44 // nsIFrame methods: 45 virtual void BuildDisplayList(nsDisplayListBuilder* aBuilder, 46 const nsDisplayListSet& aLists) override {} 47 48 virtual bool IsSVGTransformed(Matrix* aOwnTransforms, 49 Matrix* aFromParentTransforms) const override; 50 51 // SVGClipPathFrame methods: 52 53 /** 54 * Applies the clipPath by pushing a clip path onto the DrawTarget. 55 * 56 * This method must only be used if IsTrivial() returns true, otherwise use 57 * GetClipMask. 58 * 59 * @param aContext The context that the clip path is to be applied to. 60 * @param aClippedFrame The/an nsIFrame of the element that references this 61 * clipPath that is currently being processed. 62 * @param aMatrix The transform from aClippedFrame's user space to aContext's 63 * current transform. 64 */ 65 void ApplyClipPath(gfxContext& aContext, nsIFrame* aClippedFrame, 66 const gfxMatrix& aMatrix); 67 68 /** 69 * Returns an alpha mask surface containing the clipping geometry. 70 * 71 * This method must only be used if IsTrivial() returns false, otherwise use 72 * ApplyClipPath. 73 * 74 * @param aReferenceContext Used to determine the backend for and size of the 75 * returned SourceSurface, the size being limited to the device space clip 76 * extents on the context. 77 * @param aClippedFrame The/an nsIFrame of the element that references this 78 * clipPath that is currently being processed. 79 * @param aMatrix The transform from aClippedFrame's user space to aContext's 80 * current transform. 81 * @param [in, optional] aExtraMask An extra surface that the returned 82 * surface should be masked with. 83 */ 84 already_AddRefed<SourceSurface> GetClipMask( 85 gfxContext& aReferenceContext, nsIFrame* aClippedFrame, 86 const gfxMatrix& aMatrix, SourceSurface* aExtraMask = nullptr); 87 88 /** 89 * Paint mask directly onto a given context(aMaskContext). 90 * 91 * @param aMaskContext The target of mask been painting on. 92 * @param aClippedFrame The/an nsIFrame of the element that references this 93 * clipPath that is currently being processed. 94 * @param aMatrix The transform from aClippedFrame's user space to 95 * current transform. 96 * @param [in, optional] aExtraMask An extra surface that the returned 97 * surface should be masked with. 98 */ 99 void PaintClipMask(gfxContext& aMaskContext, nsIFrame* aClippedFrame, 100 const gfxMatrix& aMatrix, SourceSurface* aExtraMask); 101 102 /** 103 * aPoint is expected to be in aClippedFrame's SVG user space. 104 */ 105 bool PointIsInsideClipPath(nsIFrame* aClippedFrame, const gfxPoint& aPoint); 106 107 // Check if this clipPath is made up of more than one geometry object. 108 // If so, the clipping API in cairo isn't enough and we need to use 109 // mask based clipping. 110 bool IsTrivial(ISVGDisplayableFrame** aSingleChild = nullptr); 111 112 bool IsValid(); 113 114 // nsIFrame interface: 115 virtual nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute, 116 int32_t aModType) override; 117 118 virtual void Init(nsIContent* aContent, nsContainerFrame* aParent, 119 nsIFrame* aPrevInFlow) override; 120 121 #ifdef DEBUG_FRAME_DUMP GetFrameName(nsAString & aResult)122 virtual nsresult GetFrameName(nsAString& aResult) const override { 123 return MakeFrameName(u"SVGClipPath"_ns, aResult); 124 } 125 #endif 126 127 SVGBBox GetBBoxForClipPathFrame(const SVGBBox& aBBox, 128 const gfxMatrix& aMatrix, uint32_t aFlags); 129 130 /** 131 * If the clipPath element transforms its children due to 132 * clipPathUnits="objectBoundingBox" being set on it and/or due to the 133 * 'transform' attribute being set on it, this function returns the resulting 134 * transform. 135 */ 136 gfxMatrix GetClipPathTransform(nsIFrame* aClippedFrame); 137 138 private: 139 // SVGContainerFrame methods: 140 virtual gfxMatrix GetCanvasTM() override; 141 142 already_AddRefed<DrawTarget> CreateClipMask(gfxContext& aReferenceContext, 143 gfx::IntPoint& aOffset); 144 145 void PaintFrameIntoMask(nsIFrame* aFrame, nsIFrame* aClippedFrame, 146 gfxContext& aTarget); 147 148 // Set, during a GetClipMask() call, to the transform that still needs to be 149 // concatenated to the transform of the DrawTarget that was passed to 150 // GetClipMask in order to establish the coordinate space that the clipPath 151 // establishes for its contents (i.e. including applying 'clipPathUnits' and 152 // any 'transform' attribute set on the clipPath) specifically for clipping 153 // the frame that was passed to GetClipMask at that moment in time. This is 154 // set so that if our GetCanvasTM method is called while GetClipMask is 155 // painting its children, the returned matrix will include the transforms 156 // that should be used when creating the mask for the frame passed to 157 // GetClipMask. 158 // 159 // Note: The removal of GetCanvasTM is nearly complete, so our GetCanvasTM 160 // may not even be called soon/any more. 161 gfxMatrix mMatrixForChildren; 162 163 // Flag used to indicate whether a methods that may reenter due to 164 // following a reference to another instance is currently executing. 165 bool mIsBeingProcessed; 166 }; 167 168 } // namespace mozilla 169 170 #endif // LAYOUT_SVG_SVGCLIPPATHFRAME_H_ 171