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 __NS_SVGCLIPPATHFRAME_H__ 8 #define __NS_SVGCLIPPATHFRAME_H__ 9 10 #include "gfxMatrix.h" 11 #include "mozilla/Attributes.h" 12 #include "nsSVGContainerFrame.h" 13 #include "nsSVGUtils.h" 14 15 class gfxContext; 16 class nsSVGDisplayableFrame; 17 18 namespace mozilla { 19 class PresShell; 20 } // namespace mozilla 21 22 class nsSVGClipPathFrame final : public nsSVGContainerFrame { 23 friend nsIFrame* NS_NewSVGClipPathFrame(mozilla::PresShell* aPresShell, 24 ComputedStyle* aStyle); 25 26 typedef mozilla::gfx::Matrix Matrix; 27 typedef mozilla::gfx::SourceSurface SourceSurface; 28 typedef mozilla::image::imgDrawingParams imgDrawingParams; 29 30 protected: nsSVGClipPathFrame(ComputedStyle * aStyle,nsPresContext * aPresContext)31 explicit nsSVGClipPathFrame(ComputedStyle* aStyle, 32 nsPresContext* aPresContext) 33 : nsSVGContainerFrame(aStyle, aPresContext, kClassID), 34 mIsBeingProcessed(false) { 35 AddStateBits(NS_FRAME_IS_NONDISPLAY); 36 } 37 38 public: NS_DECL_FRAMEARENA_HELPERS(nsSVGClipPathFrame)39 NS_DECL_FRAMEARENA_HELPERS(nsSVGClipPathFrame) 40 41 // nsIFrame methods: 42 virtual void BuildDisplayList(nsDisplayListBuilder* aBuilder, 43 const nsDisplayListSet& aLists) override {} 44 45 virtual bool IsSVGTransformed(Matrix* aOwnTransforms, 46 Matrix* aFromParentTransforms) const override; 47 48 // nsSVGClipPathFrame methods: 49 50 /** 51 * Applies the clipPath by pushing a clip path onto the DrawTarget. 52 * 53 * This method must only be used if IsTrivial() returns true, otherwise use 54 * GetClipMask. 55 * 56 * @param aContext The context that the clip path is to be applied to. 57 * @param aClippedFrame The/an nsIFrame of the element that references this 58 * clipPath that is currently being processed. 59 * @param aMatrix The transform from aClippedFrame's user space to aContext's 60 * current transform. 61 */ 62 void ApplyClipPath(gfxContext& aContext, nsIFrame* aClippedFrame, 63 const gfxMatrix& aMatrix); 64 65 /** 66 * Returns an alpha mask surface containing the clipping geometry. 67 * 68 * This method must only be used if IsTrivial() returns false, otherwise use 69 * ApplyClipPath. 70 * 71 * @param aReferenceContext Used to determine the backend for and size of the 72 * returned SourceSurface, the size being limited to the device space clip 73 * extents on the context. 74 * @param aClippedFrame The/an nsIFrame of the element that references this 75 * clipPath that is currently being processed. 76 * @param aMatrix The transform from aClippedFrame's user space to aContext's 77 * current transform. 78 * @param [in, optional] aExtraMask An extra surface that the returned 79 * surface should be masked with. 80 * @param [in, optional] aExtraMasksTransform The transform to use with 81 * aExtraMask. Should be passed when aExtraMask is passed. 82 */ 83 already_AddRefed<SourceSurface> GetClipMask( 84 gfxContext& aReferenceContext, nsIFrame* aClippedFrame, 85 const gfxMatrix& aMatrix, SourceSurface* aExtraMask = nullptr, 86 const Matrix& aExtraMasksTransform = Matrix()); 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 * @param [in, optional] aExtraMasksTransform The transform to use with 99 * aExtraMask. Should be passed when aExtraMask is passed. 100 */ 101 void PaintClipMask(gfxContext& aMaskContext, nsIFrame* aClippedFrame, 102 const gfxMatrix& aMatrix, SourceSurface* aExtraMask, 103 const Matrix& aExtraMasksTransform); 104 105 /** 106 * aPoint is expected to be in aClippedFrame's SVG user space. 107 */ 108 bool PointIsInsideClipPath(nsIFrame* aClippedFrame, const gfxPoint& aPoint); 109 110 // Check if this clipPath is made up of more than one geometry object. 111 // If so, the clipping API in cairo isn't enough and we need to use 112 // mask based clipping. 113 bool IsTrivial(nsSVGDisplayableFrame** aSingleChild = nullptr); 114 115 bool IsValid(); 116 117 // nsIFrame interface: 118 virtual nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute, 119 int32_t aModType) override; 120 121 virtual void Init(nsIContent* aContent, nsContainerFrame* aParent, 122 nsIFrame* aPrevInFlow) override; 123 124 #ifdef DEBUG_FRAME_DUMP GetFrameName(nsAString & aResult)125 virtual nsresult GetFrameName(nsAString& aResult) const override { 126 return MakeFrameName(NS_LITERAL_STRING("SVGClipPath"), aResult); 127 } 128 #endif 129 130 SVGBBox GetBBoxForClipPathFrame(const SVGBBox& aBBox, 131 const gfxMatrix& aMatrix, uint32_t aFlags); 132 133 /** 134 * If the clipPath element transforms its children due to 135 * clipPathUnits="objectBoundingBox" being set on it and/or due to the 136 * 'transform' attribute being set on it, this function returns the resulting 137 * transform. 138 */ 139 gfxMatrix GetClipPathTransform(nsIFrame* aClippedFrame); 140 141 private: 142 // nsSVGContainerFrame methods: 143 virtual gfxMatrix GetCanvasTM() override; 144 145 already_AddRefed<DrawTarget> CreateClipMask(gfxContext& aReferenceContext, 146 mozilla::gfx::IntPoint& aOffset); 147 148 void PaintFrameIntoMask(nsIFrame* aFrame, nsIFrame* aClippedFrame, 149 gfxContext& aTarget); 150 151 // Set, during a GetClipMask() call, to the transform that still needs to be 152 // concatenated to the transform of the DrawTarget that was passed to 153 // GetClipMask in order to establish the coordinate space that the clipPath 154 // establishes for its contents (i.e. including applying 'clipPathUnits' and 155 // any 'transform' attribute set on the clipPath) specifically for clipping 156 // the frame that was passed to GetClipMask at that moment in time. This is 157 // set so that if our GetCanvasTM method is called while GetClipMask is 158 // painting its children, the returned matrix will include the transforms 159 // that should be used when creating the mask for the frame passed to 160 // GetClipMask. 161 // 162 // Note: The removal of GetCanvasTM is nearly complete, so our GetCanvasTM 163 // may not even be called soon/any more. 164 gfxMatrix mMatrixForChildren; 165 166 // Flag used to indicate whether a methods that may reenter due to 167 // following a reference to another instance is currently executing. 168 bool mIsBeingProcessed; 169 }; 170 171 #endif 172