layout/base/DisplayItemClip.h@b8a032363ba2 (annotated)
layout/base/DisplayItemClip.h
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
| michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | #ifndef DISPLAYITEMCLIP_H_ |
| michael@0 | 7 | #define DISPLAYITEMCLIP_H_ |
| michael@0 | 8 | |
| michael@0 | 9 | #include "nsRect.h" |
| michael@0 | 10 | #include "nsTArray.h" |
| michael@0 | 11 | #include "nsStyleConsts.h" |
| michael@0 | 12 | |
| michael@0 | 13 | class gfxContext; |
| michael@0 | 14 | class nsDisplayItem; |
| michael@0 | 15 | class nsPresContext; |
| michael@0 | 16 | class nsRegion; |
| michael@0 | 17 | |
| michael@0 | 18 | namespace mozilla { |
| michael@0 | 19 | |
| michael@0 | 20 | /** |
| michael@0 | 21 | * An DisplayItemClip represents the intersection of an optional rectangle |
| michael@0 | 22 | * with a list of rounded rectangles (which is often empty), all in appunits. |
| michael@0 | 23 | * It can represent everything CSS clipping can do to an element (except for |
| michael@0 | 24 | * SVG clip-path), including no clipping at all. |
| michael@0 | 25 | */ |
| michael@0 | 26 | class DisplayItemClip { |
| michael@0 | 27 | public: |
| michael@0 | 28 | struct RoundedRect { |
| michael@0 | 29 | nsRect mRect; |
| michael@0 | 30 | // Indices into mRadii are the NS_CORNER_* constants in nsStyleConsts.h |
| michael@0 | 31 | nscoord mRadii[8]; |
| michael@0 | 32 | |
| michael@0 | 33 | RoundedRect operator+(const nsPoint& aOffset) const { |
| michael@0 | 34 | RoundedRect r = *this; |
| michael@0 | 35 | r.mRect += aOffset; |
| michael@0 | 36 | return r; |
| michael@0 | 37 | } |
| michael@0 | 38 | bool operator==(const RoundedRect& aOther) const { |
| michael@0 | 39 | if (!mRect.IsEqualInterior(aOther.mRect)) { |
| michael@0 | 40 | return false; |
| michael@0 | 41 | } |
| michael@0 | 42 | |
| michael@0 | 43 | NS_FOR_CSS_HALF_CORNERS(corner) { |
| michael@0 | 44 | if (mRadii[corner] != aOther.mRadii[corner]) { |
| michael@0 | 45 | return false; |
| michael@0 | 46 | } |
| michael@0 | 47 | } |
| michael@0 | 48 | return true; |
| michael@0 | 49 | } |
| michael@0 | 50 | bool operator!=(const RoundedRect& aOther) const { |
| michael@0 | 51 | return !(*this == aOther); |
| michael@0 | 52 | } |
| michael@0 | 53 | }; |
| michael@0 | 54 | |
| michael@0 | 55 | // Constructs a DisplayItemClip that does no clipping at all. |
| michael@0 | 56 | DisplayItemClip() : mHaveClipRect(false) {} |
| michael@0 | 57 | |
| michael@0 | 58 | void SetTo(const nsRect& aRect); |
| michael@0 | 59 | void SetTo(const nsRect& aRect, const nscoord* aRadii); |
| michael@0 | 60 | void IntersectWith(const DisplayItemClip& aOther); |
| michael@0 | 61 | |
| michael@0 | 62 | // Apply this |DisplayItemClip| to the given gfxContext. Any saving of state |
| michael@0 | 63 | // or clearing of other clips must be done by the caller. |
| michael@0 | 64 | // See aBegin/aEnd note on ApplyRoundedRectsTo. |
| michael@0 | 65 | void ApplyTo(gfxContext* aContext, nsPresContext* aPresContext, |
| michael@0 | 66 | uint32_t aBegin = 0, uint32_t aEnd = UINT32_MAX); |
| michael@0 | 67 | |
| michael@0 | 68 | void ApplyRectTo(gfxContext* aContext, int32_t A2D) const; |
| michael@0 | 69 | // Applies the rounded rects in this Clip to aContext |
| michael@0 | 70 | // Will only apply rounded rects from aBegin (inclusive) to aEnd |
| michael@0 | 71 | // (exclusive) or the number of rounded rects, whichever is smaller. |
| michael@0 | 72 | void ApplyRoundedRectsTo(gfxContext* aContext, int32_t A2DPRInt32, |
| michael@0 | 73 | uint32_t aBegin, uint32_t aEnd) const; |
| michael@0 | 74 | |
| michael@0 | 75 | // Draw (fill) the rounded rects in this clip to aContext |
| michael@0 | 76 | void DrawRoundedRectsTo(gfxContext* aContext, int32_t A2D, |
| michael@0 | 77 | uint32_t aBegin, uint32_t aEnd) const; |
| michael@0 | 78 | // 'Draw' (create as a path, does not stroke or fill) aRoundRect to aContext |
| michael@0 | 79 | void AddRoundedRectPathTo(gfxContext* aContext, int32_t A2D, |
| michael@0 | 80 | const RoundedRect &aRoundRect) const; |
| michael@0 | 81 | |
| michael@0 | 82 | // Returns true if the intersection of aRect and this clip region is |
| michael@0 | 83 | // non-empty. This is precise for DisplayItemClips with at most one |
| michael@0 | 84 | // rounded rectangle. When multiple rounded rectangles are present, we just |
| michael@0 | 85 | // check that the rectangle intersects all of them (but possibly in different |
| michael@0 | 86 | // places). So it may return true when the correct answer is false. |
| michael@0 | 87 | bool MayIntersect(const nsRect& aRect) const; |
| michael@0 | 88 | // Return a rectangle contained in the intersection of aRect with this |
| michael@0 | 89 | // clip region. Tries to return the largest possible rectangle, but may |
| michael@0 | 90 | // not succeed. |
| michael@0 | 91 | nsRect ApproximateIntersectInward(const nsRect& aRect) const; |
| michael@0 | 92 | |
| michael@0 | 93 | /* |
| michael@0 | 94 | * Computes a region which contains the clipped area of this DisplayItemClip, |
| michael@0 | 95 | * or if aOldClip is non-null, the union of the clipped area of this |
| michael@0 | 96 | * DisplayItemClip with the clipped area of aOldClip translated by aShift. |
| michael@0 | 97 | * The result is stored in aCombined. If the result would be infinite |
| michael@0 | 98 | * (because one or both of the clips does no clipping), returns false. |
| michael@0 | 99 | */ |
| michael@0 | 100 | bool ComputeRegionInClips(DisplayItemClip* aOldClip, |
| michael@0 | 101 | const nsPoint& aShift, |
| michael@0 | 102 | nsRegion* aCombined) const; |
| michael@0 | 103 | |
| michael@0 | 104 | // Returns false if aRect is definitely not clipped by a rounded corner in |
| michael@0 | 105 | // this clip. Returns true if aRect is clipped by a rounded corner in this |
| michael@0 | 106 | // clip or it can not be quickly determined that it is not clipped by a |
| michael@0 | 107 | // rounded corner in this clip. |
| michael@0 | 108 | bool IsRectClippedByRoundedCorner(const nsRect& aRect) const; |
| michael@0 | 109 | |
| michael@0 | 110 | // Returns false if aRect is definitely not clipped by anything in this clip. |
| michael@0 | 111 | // Fast but not necessarily accurate. |
| michael@0 | 112 | bool IsRectAffectedByClip(const nsRect& aRect) const; |
| michael@0 | 113 | |
| michael@0 | 114 | // Intersection of all rects in this clip ignoring any rounded corners. |
| michael@0 | 115 | nsRect NonRoundedIntersection() const; |
| michael@0 | 116 | |
| michael@0 | 117 | // Intersect the given rects with all rects in this clip, ignoring any |
| michael@0 | 118 | // rounded corners. |
| michael@0 | 119 | nsRect ApplyNonRoundedIntersection(const nsRect& aRect) const; |
| michael@0 | 120 | |
| michael@0 | 121 | // Gets rid of any rounded corners in this clip. |
| michael@0 | 122 | void RemoveRoundedCorners(); |
| michael@0 | 123 | |
| michael@0 | 124 | // Adds the difference between Intersect(*this + aPoint, aBounds) and |
| michael@0 | 125 | // Intersect(aOther, aOtherBounds) to aDifference (or a bounding-box thereof). |
| michael@0 | 126 | void AddOffsetAndComputeDifference(const nsPoint& aPoint, const nsRect& aBounds, |
| michael@0 | 127 | const DisplayItemClip& aOther, const nsRect& aOtherBounds, |
| michael@0 | 128 | nsRegion* aDifference); |
| michael@0 | 129 | |
| michael@0 | 130 | bool operator==(const DisplayItemClip& aOther) const { |
| michael@0 | 131 | return mHaveClipRect == aOther.mHaveClipRect && |
| michael@0 | 132 | (!mHaveClipRect || mClipRect.IsEqualInterior(aOther.mClipRect)) && |
| michael@0 | 133 | mRoundedClipRects == aOther.mRoundedClipRects; |
| michael@0 | 134 | } |
| michael@0 | 135 | bool operator!=(const DisplayItemClip& aOther) const { |
| michael@0 | 136 | return !(*this == aOther); |
| michael@0 | 137 | } |
| michael@0 | 138 | |
| michael@0 | 139 | bool HasClip() const { return mHaveClipRect; } |
| michael@0 | 140 | const nsRect& GetClipRect() const |
| michael@0 | 141 | { |
| michael@0 | 142 | NS_ASSERTION(HasClip(), "No clip rect!"); |
| michael@0 | 143 | return mClipRect; |
| michael@0 | 144 | } |
| michael@0 | 145 | |
| michael@0 | 146 | void MoveBy(nsPoint aPoint); |
| michael@0 | 147 | |
| michael@0 | 148 | #ifdef MOZ_DUMP_PAINTING |
| michael@0 | 149 | nsCString ToString() const; |
| michael@0 | 150 | #endif |
| michael@0 | 151 | |
| michael@0 | 152 | /** |
| michael@0 | 153 | * Find the largest N such that the first N rounded rects in 'this' are |
| michael@0 | 154 | * equal to the first N rounded rects in aOther, and N <= aMax. |
| michael@0 | 155 | */ |
| michael@0 | 156 | uint32_t GetCommonRoundedRectCount(const DisplayItemClip& aOther, |
| michael@0 | 157 | uint32_t aMax) const; |
| michael@0 | 158 | uint32_t GetRoundedRectCount() const { return mRoundedClipRects.Length(); } |
| michael@0 | 159 | void AppendRoundedRects(nsTArray<RoundedRect>* aArray, uint32_t aCount) const; |
| michael@0 | 160 | |
| michael@0 | 161 | static const DisplayItemClip& NoClip(); |
| michael@0 | 162 | |
| michael@0 | 163 | static void Shutdown(); |
| michael@0 | 164 | |
| michael@0 | 165 | private: |
| michael@0 | 166 | nsRect mClipRect; |
| michael@0 | 167 | nsTArray<RoundedRect> mRoundedClipRects; |
| michael@0 | 168 | // If mHaveClipRect is false then this object represents no clipping at all |
| michael@0 | 169 | // and mRoundedClipRects must be empty. |
| michael@0 | 170 | bool mHaveClipRect; |
| michael@0 | 171 | }; |
| michael@0 | 172 | |
| michael@0 | 173 | } |
| michael@0 | 174 | |
| michael@0 | 175 | #endif /* DISPLAYITEMCLIP_H_ */ |
