gecko/layout/base/DisplayItemClip.h
Robert O'Callahan 74c9caea47 Bug 841192. Part 2: Move FrameLayerBuilder::Clip to DisplayItemClip. r=mattwoodrow
--HG--
extra : rebase_source : 2950e5dd64e217a406ede2dc9f6682b5e0540975
2013-03-04 22:55:59 +13:00

123 lines
4.5 KiB
C++

/* -*- Mode: C++; tab-width: 20; 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 DISPLAYITEMCLIP_H_
#define DISPLAYITEMCLIP_H_
#include "nsRect.h"
#include "nsTArray.h"
#include "nsStyleConsts.h"
class gfxContext;
class nsDisplayItem;
class nsPresContext;
class nsRegion;
namespace mozilla {
/**
* An DisplayItemClip represents the intersection of an optional rectangle
* with a list of rounded rectangles (which is often empty), all in appunits.
* It can represent everything CSS clipping can do to an element (except for
* SVG clip-path), including no clipping at all.
*/
struct DisplayItemClip {
struct RoundedRect {
nsRect mRect;
// Indices into mRadii are the NS_CORNER_* constants in nsStyleConsts.h
nscoord mRadii[8];
RoundedRect operator+(const nsPoint& aOffset) const {
RoundedRect r = *this;
r.mRect += aOffset;
return r;
}
bool operator==(const RoundedRect& aOther) const {
if (!mRect.IsEqualInterior(aOther.mRect)) {
return false;
}
NS_FOR_CSS_HALF_CORNERS(corner) {
if (mRadii[corner] != aOther.mRadii[corner]) {
return false;
}
}
return true;
}
bool operator!=(const RoundedRect& aOther) const {
return !(*this == aOther);
}
};
nsRect mClipRect;
nsTArray<RoundedRect> mRoundedClipRects;
bool mHaveClipRect;
// Constructs a DisplayItemClip that does no clipping at all.
DisplayItemClip() : mHaveClipRect(false) {}
// Construct as the intersection of aOther and aClipItem.
DisplayItemClip(const DisplayItemClip& aOther, nsDisplayItem* aClipItem);
// Apply this |DisplayItemClip| to the given gfxContext. Any saving of state
// or clearing of other clips must be done by the caller.
// See aBegin/aEnd note on ApplyRoundedRectsTo.
void ApplyTo(gfxContext* aContext, nsPresContext* aPresContext,
uint32_t aBegin = 0, uint32_t aEnd = UINT32_MAX);
void ApplyRectTo(gfxContext* aContext, int32_t A2D) const;
// Applies the rounded rects in this Clip to aContext
// Will only apply rounded rects from aBegin (inclusive) to aEnd
// (exclusive) or the number of rounded rects, whichever is smaller.
void ApplyRoundedRectsTo(gfxContext* aContext, int32_t A2DPRInt32,
uint32_t aBegin, uint32_t aEnd) const;
// Draw (fill) the rounded rects in this clip to aContext
void DrawRoundedRectsTo(gfxContext* aContext, int32_t A2D,
uint32_t aBegin, uint32_t aEnd) const;
// 'Draw' (create as a path, does not stroke or fill) aRoundRect to aContext
void AddRoundedRectPathTo(gfxContext* aContext, int32_t A2D,
const RoundedRect &aRoundRect) const;
// Return a rectangle contained in the intersection of aRect with this
// clip region. Tries to return the largest possible rectangle, but may
// not succeed.
nsRect ApproximateIntersect(const nsRect& aRect) const;
// Returns false if aRect is definitely not clipped by a rounded corner in
// this clip. Returns true if aRect is clipped by a rounded corner in this
// clip or it can not be quickly determined that it is not clipped by a
// rounded corner in this clip.
bool IsRectClippedByRoundedCorner(const nsRect& aRect) const;
// Intersection of all rects in this clip ignoring any rounded corners.
nsRect NonRoundedIntersection() const;
// Intersect the given rects with all rects in this clip, ignoring any
// rounded corners.
nsRect ApplyNonRoundedIntersection(const nsRect& aRect) const;
// Gets rid of any rounded corners in this clip.
void RemoveRoundedCorners();
// Adds the difference between Intersect(*this + aPoint, aBounds) and
// Intersect(aOther, aOtherBounds) to aDifference (or a bounding-box thereof).
void AddOffsetAndComputeDifference(const nsPoint& aPoint, const nsRect& aBounds,
const DisplayItemClip& aOther, const nsRect& aOtherBounds,
nsRegion* aDifference);
bool operator==(const DisplayItemClip& aOther) const {
return mHaveClipRect == aOther.mHaveClipRect &&
(!mHaveClipRect || mClipRect.IsEqualInterior(aOther.mClipRect)) &&
mRoundedClipRects == aOther.mRoundedClipRects;
}
bool operator!=(const DisplayItemClip& aOther) const {
return !(*this == aOther);
}
};
}
#endif /* DISPLAYITEMCLIP_H_ */