renderlayer.h

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2003, 2009 Apple Inc. All rights reserved.
 *
 * Portions are Copyright (C) 1998 Netscape Communications Corporation.
 *
 * Other contributors:
 *   Robert O'Callahan <[e-mail]>
 *   David Baron <[e-mail]>
 *   Christian Biesinger <[e-mail]>
 *   Randall Jesup <[e-mail]>
 *   Roland Mainz <[e-mail]>
 *   Josh Soref <[e-mail]>
 *   Boris Zbarsky <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Alternatively, the contents of this file may be used under the terms
 * of either the Mozilla Public License Version 1.1, found at
 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
 * (the "GPL"), in which case the provisions of the MPL or the GPL are
 * applicable instead of those above.  If you wish to allow use of your
 * version of this file only under the terms of one of those two
 * licenses (the MPL or the GPL) and not to allow others to use your
 * version of this file under the LGPL, indicate your decision by
 * deletingthe provisions above and replace them with the notice and
 * other provisions required by the MPL or the GPL, as the case may be.
 * If you do not delete the provisions above, a recipient may use your
 * version of this file under any of the LGPL, the MPL or the GPL.
 */

#ifndef RenderLayer_h
#define RenderLayer_h

#include "RenderBox.h"
#include "ScrollBehavior.h"
#include "ScrollbarClient.h"
#include "Timer.h"
#include <wtf/OwnPtr.h>

namespace WebCore {

class CachedResource;
class HitTestRequest;
class HitTestResult;
class HitTestingTransformState;
class RenderFrameSet;
class RenderMarquee;
class RenderReplica;
class RenderScrollbarPart;
class RenderStyle;
class RenderTable;
class RenderText;
class RenderView;
class Scrollbar;
class TransformationMatrix;

#if USE(ACCELERATED_COMPOSITING)
class RenderLayerBacking;
class RenderLayerCompositor;
#endif

class ClipRects {
public:
    ClipRects()
        : m_refCnt(0)
        , m_fixed(false)
    {
    }

    ClipRects(const IntRect& r)
        : m_overflowClipRect(r)
        , m_fixedClipRect(r)
        , m_posClipRect(r)
        , m_refCnt(0)
        , m_fixed(false)
    {
    }

    ClipRects(const ClipRects& other)
        : m_overflowClipRect(other.overflowClipRect())
        , m_fixedClipRect(other.fixedClipRect())
        , m_posClipRect(other.posClipRect())
        , m_refCnt(0)
        , m_fixed(other.fixed())
    {
    }

    void reset(const IntRect& r)
    {
        m_overflowClipRect = r;
        m_fixedClipRect = r;
        m_posClipRect = r;
        m_fixed = false;
    }
    
    const IntRect& overflowClipRect() const { return m_overflowClipRect; }
    void setOverflowClipRect(const IntRect& r) { m_overflowClipRect = r; }

    const IntRect& fixedClipRect() const { return m_fixedClipRect; }
    void setFixedClipRect(const IntRect&r) { m_fixedClipRect = r; }

    const IntRect& posClipRect() const { return m_posClipRect; }
    void setPosClipRect(const IntRect& r) { m_posClipRect = r; }

    bool fixed() const { return m_fixed; }
    void setFixed(bool fixed) { m_fixed = fixed; }

    void ref() { m_refCnt++; }
    void deref(RenderArena* renderArena) { if (--m_refCnt == 0) destroy(renderArena); }

    void destroy(RenderArena*);

    // Overloaded new operator.
    void* operator new(size_t, RenderArena*) throw();

    // Overridden to prevent the normal delete from being called.
    void operator delete(void*, size_t);

    bool operator==(const ClipRects& other) const
    {
        return m_overflowClipRect == other.overflowClipRect() &&
               m_fixedClipRect == other.fixedClipRect() &&
               m_posClipRect == other.posClipRect() &&
               m_fixed == other.fixed();
    }

    ClipRects& operator=(const ClipRects& other)
    {
        m_overflowClipRect = other.overflowClipRect();
        m_fixedClipRect = other.fixedClipRect();
        m_posClipRect = other.posClipRect();
        m_fixed = other.fixed();
        return *this;
    }
        
private:
    // The normal operator new is disallowed on all render objects.
    void* operator new(size_t) throw();

private:
    IntRect m_overflowClipRect;
    IntRect m_fixedClipRect;
    IntRect m_posClipRect;
    unsigned m_refCnt : 31;
    bool m_fixed : 1;
};

class RenderLayer : public ScrollbarClient {
public:
    friend class RenderReplica;

    RenderLayer(RenderBoxModelObject*);
    ~RenderLayer();

    RenderBoxModelObject* renderer() const { return m_renderer; }
    RenderBox* renderBox() const { return m_renderer && m_renderer->isBox() ? toRenderBox(m_renderer) : 0; }
    RenderLayer* parent() const { return m_parent; }
    RenderLayer* previousSibling() const { return m_previous; }
    RenderLayer* nextSibling() const { return m_next; }
    RenderLayer* firstChild() const { return m_first; }
    RenderLayer* lastChild() const { return m_last; }

    void addChild(RenderLayer* newChild, RenderLayer* beforeChild = 0);
    RenderLayer* removeChild(RenderLayer*);

    void removeOnlyThisLayer();
    void insertOnlyThisLayer();

    void repaintIncludingDescendants();

#if USE(ACCELERATED_COMPOSITING)
    // Indicate that the layer contents need to be repainted. Only has an effect
    // if layer compositing is being used,
    void setBackingNeedsRepaint();
    void setBackingNeedsRepaintInRect(const IntRect& r); // r is in the coordinate space of the layer's render object
#endif

    void styleChanged(StyleDifference, const RenderStyle*);

    RenderMarquee* marquee() const { return m_marquee; }
    void suspendMarquees();

    bool isNormalFlowOnly() const { return m_isNormalFlowOnly; }
    bool isSelfPaintingLayer() const;

    bool requiresSlowRepaints() const;

    bool isTransparent() const;
    RenderLayer* transparentPaintingAncestor();
    void beginTransparencyLayers(GraphicsContext*, const RenderLayer* rootLayer);

    bool hasReflection() const { return renderer()->hasReflection(); }
    RenderReplica* reflection() const { return m_reflection; }
    RenderLayer* reflectionLayer() const;

    const RenderLayer* root() const
    {
        const RenderLayer* curr = this;
        while (curr->parent())
            curr = curr->parent();
        return curr;
    }
    
    int x() const { return m_x; }
    int y() const { return m_y; }
    void setLocation(int x, int y)
    {
        m_x = x;
        m_y = y;
    }

    int width() const { return m_width; }
    int height() const { return m_height; }
    void setWidth(int w) { m_width = w; }
    void setHeight(int h) { m_height = h; }

    int scrollWidth();
    int scrollHeight();

    void panScrollFromPoint(const IntPoint&);

    // Scrolling methods for layers that can scroll their overflow.
    void scrollByRecursively(int xDelta, int yDelta);
    void addScrolledContentOffset(int& x, int& y) const;
    void subtractScrolledContentOffset(int& x, int& y) const;
    IntSize scrolledContentOffset() const { return IntSize(scrollXOffset() + m_scrollLeftOverflow, scrollYOffset()); }

    int scrollXOffset() const { return m_scrollX + m_scrollOriginX; }
    int scrollYOffset() const { return m_scrollY; }

    void scrollToOffset(int x, int y, bool updateScrollbars = true, bool repaint = true);
    void scrollToXOffset(int x) { scrollToOffset(x, m_scrollY); }
    void scrollToYOffset(int y) { scrollToOffset(m_scrollX + m_scrollOriginX, y); }
    void scrollRectToVisible(const IntRect&, bool scrollToAnchor = false, const ScrollAlignment& alignX = ScrollAlignment::alignCenterIfNeeded, const ScrollAlignment& alignY = ScrollAlignment::alignCenterIfNeeded);

    IntRect getRectToExpose(const IntRect& visibleRect, const IntRect& exposeRect, const ScrollAlignment& alignX, const ScrollAlignment& alignY);

    void setHasHorizontalScrollbar(bool);
    void setHasVerticalScrollbar(bool);

    PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
    void destroyScrollbar(ScrollbarOrientation);

    Scrollbar* horizontalScrollbar() const { return m_hBar.get(); }
    Scrollbar* verticalScrollbar() const { return m_vBar.get(); }

    int verticalScrollbarWidth() const;
    int horizontalScrollbarHeight() const;

    void positionOverflowControls(int tx, int ty);
    bool isPointInResizeControl(const IntPoint& absolutePoint) const;
    bool hitTestOverflowControls(HitTestResult&);
    IntSize offsetFromResizeCorner(const IntPoint& absolutePoint) const;

    void paintOverflowControls(GraphicsContext*, int tx, int ty, const IntRect& damageRect);
    void paintScrollCorner(GraphicsContext*, int tx, int ty, const IntRect& damageRect);
    void paintResizer(GraphicsContext*, int tx, int ty, const IntRect& damageRect);

    void updateScrollInfoAfterLayout();

    bool scroll(ScrollDirection, ScrollGranularity, float multiplier = 1.0f);
    void autoscroll();

    void resize(const PlatformMouseEvent&, const IntSize&);
    bool inResizeMode() const { return m_inResizeMode; }
    void setInResizeMode(bool b) { m_inResizeMode = b; }

    bool isRootLayer() const { return renderer()->isRenderView(); }
    
#if USE(ACCELERATED_COMPOSITING)
    RenderLayerCompositor* compositor() const;
#endif
    
    void updateLayerPosition();
    void updateLayerPositions(bool doFullRepaint = false, bool checkForRepaint = true);

    void updateTransform();

    void relativePositionOffset(int& relX, int& relY) const { relX += m_relX; relY += m_relY; }
    IntSize relativePositionOffset() const { return IntSize(m_relX, m_relY); }

    void clearClipRectsIncludingDescendants();
    void clearClipRects();

    // Get the enclosing stacking context for this layer.  A stacking context is a layer
    // that has a non-auto z-index.
    RenderLayer* stackingContext() const;
    bool isStackingContext() const { return !hasAutoZIndex() || renderer()->isRenderView(); }

    void dirtyZOrderLists();
    void dirtyStackingContextZOrderLists();