gecko-dev/layout/base/nsDisplayListInvalidation.h

97 lines
2.5 KiB
C++

/*-*- Mode: C++; tab-width: 2; 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 NSDISPLAYLISTINVALIDATION_H_
#define NSDISPLAYLISTINVALIDATION_H_
#include "nsRect.h"
class nsDisplayItem;
class nsDisplayListBuilder;
/**
* This stores the geometry of an nsDisplayItem, and the area
* that will be affected when painting the item.
*
* It is used to retain information about display items so they
* can be compared against new display items in the next paint.
*/
class nsDisplayItemGeometry
{
public:
nsDisplayItemGeometry(nsDisplayItem* aItem, nsDisplayListBuilder* aBuilder);
virtual ~nsDisplayItemGeometry();
/**
* Compute the area required to be invalidated if this
* display item is removed.
*/
const nsRect& ComputeInvalidationRegion() { return mBounds; }
/**
* Shifts all retained areas of the nsDisplayItemGeometry by the given offset.
*
* This is used to compensate for scrolling, since the destination buffer
* can scroll without requiring a full repaint.
*
* @param aOffset Offset to shift by.
*/
virtual void MoveBy(const nsPoint& aOffset) = 0;
/**
* Bounds of the display item
*/
nsRect mBounds;
};
/**
* A default geometry implementation, used by nsDisplayItem. Retains
* and compares the bounds, and border rect.
*
* This should be sufficient for the majority of display items.
*/
class nsDisplayItemGenericGeometry : public nsDisplayItemGeometry
{
public:
nsDisplayItemGenericGeometry(nsDisplayItem* aItem, nsDisplayListBuilder* aBuilder);
virtual void MoveBy(const nsPoint& aOffset);
nsRect mBorderRect;
};
class nsDisplayBorderGeometry : public nsDisplayItemGeometry
{
public:
nsDisplayBorderGeometry(nsDisplayItem* aItem, nsDisplayListBuilder* aBuilder);
virtual void MoveBy(const nsPoint& aOffset);
nsRect mContentRect;
};
class nsDisplayBackgroundGeometry : public nsDisplayItemGeometry
{
public:
nsDisplayBackgroundGeometry(nsDisplayItem* aItem, nsDisplayListBuilder* aBuilder);
virtual void MoveBy(const nsPoint& aOffset);
nsRect mPaddingRect;
nsRect mContentRect;
};
class nsDisplayBoxShadowInnerGeometry : public nsDisplayItemGeometry
{
public:
nsDisplayBoxShadowInnerGeometry(nsDisplayItem* aItem, nsDisplayListBuilder* aBuilder);
virtual void MoveBy(const nsPoint& aOffset);
nsRect mPaddingRect;
};
#endif /*NSDISPLAYLISTINVALIDATION_H_*/