src/rendering/render_layer.h

/*
 * Copyright (C) 2003 Apple Computer, Inc.
 *
 * Portions are Copyright (C) 1998 Netscape Communications Corporation.
 *
 * Other contributors:
 *   Robert O'Callahan <roc+@cs.cmu.edu>
 *   David Baron <dbaron@fas.harvard.edu>
 *   Christian Biesinger <cbiesinger@web.de>
 *   Randall Jesup <rjesup@wgate.com>
 *   Roland Mainz <roland.mainz@informatik.med.uni-giessen.de>
 *   Josh Soref <timeless@mac.com>
 *   Boris Zbarsky <bzbarsky@mit.edu>
 *
 * 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 render_layer_h
#define render_layer_h

#include <QColor>
#include <QRect>
#include <assert.h>

#include "render_object.h"

//template <class T*> class QVector;

namespace khtml
{
class RenderObject;
class RenderScrollMediator;
class ScrollBarWidget;

class RenderScrollMediator: public QObject
{
    Q_OBJECT
public:
    RenderScrollMediator(RenderLayer *layer)
        : m_layer(layer), m_waitingForUpdate(false) {}

public Q_SLOTS:
    void slotValueChanged();

private:
    RenderLayer *m_layer;
    bool m_waitingForUpdate;
};

// This class handles the auto-scrolling of layers with overflow: marquee.
class Marquee: public QObject
{
    Q_OBJECT

public:
    Marquee(RenderLayer *l);

    void timerEvent(QTimerEvent *) override;

    int speed() const
    {
        return m_speed;
    }
    int marqueeSpeed() const;
    EMarqueeDirection direction() const;
    EMarqueeDirection reverseDirection() const
    {
        return static_cast<EMarqueeDirection>(-direction());
    }
    bool isHorizontal() const;
    bool isUnfurlMarquee() const;
    int unfurlPos() const
    {
        return m_unfurlPos;
    }

    EWhiteSpace whiteSpace()
    {
        return KDE_CAST_BF_ENUM(EWhiteSpace, m_whiteSpace);
    }

    int computePosition(EMarqueeDirection dir, bool stopAtClientEdge);

    void setEnd(int end)
    {
        m_end = end;
    }

    void start();
    void suspend();
    void stop();

    void updateMarqueeStyle();
    void updateMarqueePosition();

private:
    RenderLayer *m_layer;
    int m_currentLoop;
    int m_totalLoops;
    int m_timerId;
    int m_start;
    int m_end;
    int m_speed;
    int m_unfurlPos;
    bool m_reset: 1;
    bool m_suspended: 1;
    bool m_stopped: 1;
    KDE_BF_ENUM(EWhiteSpace) m_whiteSpace : 3;
    KDE_BF_ENUM(EMarqueeDirection) m_direction : 4;
};

class RenderLayer
{
public:
    static ScrollBarWidget *gScrollBar;

    RenderLayer(RenderObject *object);
    ~RenderLayer();

    RenderObject *renderer() const
    {
        return m_object;
    }
    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 = nullptr);
    RenderLayer *removeChild(RenderLayer *oldChild);

    void removeOnlyThisLayer();
    void insertOnlyThisLayer();

    void styleChanged();

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

    bool isOverflowOnly() const
    {
        return m_isOverflowOnly;
    }

    bool isTransparent() const;
    RenderLayer *transparentAncestor() const;

    RenderLayer *root()
    {
        RenderLayer *curr = this;
        while (curr->parent()) {
            curr = curr->parent();
        }
        return curr;
    }

    int xPos() const
    {
        return m_x;
    }
    int yPos() const
    {
        return m_y;
    }

    int width() const;
    int height() const;

    int scrollWidth() const
    {
        return m_scrollWidth;
    }
    int scrollHeight() const
    {
        return m_scrollHeight;
    }

    void resize(int w, int h)
    {
        m_scrollWidth = w; m_scrollHeight = h;
    }

    void setPos(int xPos, int yPos)
    {
        m_x = xPos;
        m_y = yPos;
    }

    // Scrolling methods for layers that can scroll their overflow.
    void scrollOffset(int &x, int &y);
    void subtractScrollOffset(int &x, int &y);
    void checkInlineRelOffset(const RenderObject *o, int &x, int &y);
    int scrollXOffset()
    {
        return m_scrollX + m_scrollXOrigin;
    }
    int scrollYOffset()
    {
        return m_scrollY;
    }
    void scrollToOffset(int x, int y, bool updateScrollbars = true, bool repaint = true, bool dispatchEvent = true);
    void scrollToXOffset(int x)
    {
        scrollToOffset(x, m_scrollY);
    }
    void scrollToYOffset(int y)
    {
        scrollToOffset(m_scrollX + m_scrollXOrigin, y);
    }
    void resetXOffset()
    {
        scrollToOffset(0, m_scrollY, false, false, false);
    }
    void resetYOffset()
    {
        scrollToOffset(m_scrollX + m_scrollXOrigin, 0, false, false, false);
    }
    void showScrollbar(Qt::Orientation, bool);
    ScrollBarWidget *horizontalScrollbar()
    {
        return m_hBar;
    }
    ScrollBarWidget *verticalScrollbar()
    {
        return m_vBar;
    }
    bool hasReversedScrollbar() const;
    int verticalScrollbarWidth();
    int horizontalScrollbarHeight();
    void positionScrollbars(const QRect &damageRect);
    void paintScrollbars(RenderObject::PaintInfo &pI);
    void checkScrollbarsAfterLayout();
    void slotValueChanged(int);
    void repaint(Priority p = NormalPriority, bool markForRepaint = false);
    void updateScrollPositionFromScrollbars();

    void updateLayerPosition();
    void updateLayerPositions(RenderLayer *rootLayer, bool doFullRepaint = false, bool checkForRepaint = false);

    // 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()->isCanvas();
    }

    void dirtyZOrderLists();
    void updateZOrderLists();
    QVector<RenderLayer *> *posZOrderList() const
    {
        return m_posZOrderList;
    }
    QVector<RenderLayer *> *negZOrderList() const
    {
        return m_negZOrderList;
    }

    void dirtyOverflowList();
    void updateOverflowList();
    QVector<RenderLayer *> *overflowList() const
    {
        return m_overflowList;
    }

    bool hasVisibleContent() const
    {
        return m_hasVisibleContent;
    }
    void setHasVisibleContent(bool b);
    void dirtyVisibleContentStatus();

    void setHasOverlaidWidgets(bool b = true)
    {
        m_hasOverlaidWidgets = b;
    }
    bool hasOverlaidWidgets() const
    {
        return m_hasOverlaidWidgets;
    }
    QRegion getMask() const
    {
        return m_region;
    }
    QRegion paintedRegion(RenderLayer *rootLayer);
    void updateWidgetMasks(RenderLayer *rootLayer);

    // Gets the nearest enclosing positioned ancestor layer (also includes
    // the <html> layer and the root layer).
    RenderLayer *enclosingPositionedAncestor() const;

    void convertToLayerCoords(const RenderLayer *ancestorLayer, int &x, int &y) const;

    bool hasAutoZIndex() const
    {
        return renderer()->style()->hasAutoZIndex();
    }
    int zIndex() const
    {
        return renderer()->style()->zIndex();
    }

    // The two main functions that use the layer system.  The paint method
    // paints the layers that intersect the damage rect from back to
    // front.  The nodeAtPoint method looks for mouse events by walking
    // layers that intersect the point from front to back.
    KHTML_EXPORT void paint(QPainter *p, const QRect &damageRect, bool selectionOnly = false);
    bool nodeAtPoint(RenderObject::NodeInfo &info, int x, int y);

    // This method figures out our layerBounds in coordinates relative to
    // |rootLayer}.  It also computes our background and foreground clip rects
    // for painting/event handling.
    void calculateRects(const RenderLayer *rootLayer, const QRect &paintDirtyRect, QRect &layerBounds,
                        QRect &backgroundRect, QRect &foregroundRect);
    void calculateClipRects(const RenderLayer *rootLayer, QRect &overflowClipRect,
                            QRect &posClipRect, QRect &fixedClipRect);

    bool intersectsDamageRect(const QRect &layerBounds, const QRect &damageRect) const;
    bool containsPoint(int x, int y, const QRect &damageRect) const;

    void updateHoverActiveState(RenderObject::NodeInfo &info);

    void detach(RenderArena *renderArena);

#ifdef ENABLE_DUMP
    KHTML_EXPORT void dump(QTextStream &stream, const QString &ind = QString());
#endif

    // Overloaded new operator.  Derived classes must override operator new
    // in order to allocate out of the RenderArena.
    void *operator new(size_t sz, RenderArena *renderArena) throw();

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

private:
    // The normal operator new is disallowed on all render objects.
    void *operator new(size_t sz) throw();

private:
    void setNextSibling(RenderLayer *next)
    {
        m_next = next;
    }
    void setPreviousSibling(RenderLayer *prev)
    {
        m_previous = prev;
    }
    void setParent(RenderLayer *parent)
    {
        m_parent = parent;
    }
    void setFirstChild(RenderLayer *first)
    {
        m_first = first;
    }
    void setLastChild(RenderLayer *last)
    {
        m_last = last;
    }

    void collectLayers(QVector<RenderLayer *> *&, QVector<RenderLayer *> *&);

    KHTML_EXPORT void paintLayer(RenderLayer *rootLayer, QPainter *p, const QRect &paintDirtyRect, bool selectionOnly = false);
    RenderLayer *nodeAtPointForLayer(RenderLayer *rootLayer, RenderObject::NodeInfo &info,
                                     int x, int y, const QRect &hitTestRect);
    bool shouldBeOverflowOnly() const;

    void childVisibilityChanged(bool newVisibility);
    void dirtyVisibleDescendantStatus();
    void updateVisibilityStatus();

protected:
    void setClip(QPainter *p, const QRect &paintDirtyRect, const QRect &clipRect, bool setup = false);
    void restoreClip(QPainter *p, const QRect &paintDirtyRect, const QRect &clipRect, bool cleanup = false);

    RenderObject *m_object;

    RenderLayer *m_parent;
    RenderLayer *m_previous;
    RenderLayer *m_next;

    RenderLayer *m_first;
    RenderLayer *m_last;

    // Our (x,y) coordinates are in our parent layer's coordinate space.
    int m_x;
    int m_y;

    // Our scroll offsets if the view is scrolled.
    int m_scrollX;
    int m_scrollY;

    // the reference for our x offset (will vary depending on layout direction)
    int m_scrollXOrigin;

    // The width/height of our scrolled area.
    int m_scrollWidth;
    int m_scrollHeight;

    // For layers with overflow, we have a pair of scrollbars.
    ScrollBarWidget *m_hBar;
    ScrollBarWidget *m_vBar;
    QPixmap *m_buffer[2];

    RenderScrollMediator *m_scrollMediator;

    // For layers that establish stacking contexts, m_posZOrderList holds a sorted list of all the
    // descendant layers within the stacking context that have z-indices of 0 or greater
    // (auto will count as 0).  m_negZOrderList holds descendants within our stacking context with negative
    // z-indices.
    QVector<RenderLayer *> *m_posZOrderList;
    QVector<RenderLayer *> *m_negZOrderList;

    // This list contains our overflow child layers.
    QVector<RenderLayer *> *m_overflowList;

    bool m_zOrderListsDirty: 1;
    bool m_overflowListDirty: 1;
    bool m_isOverflowOnly: 1;
    bool m_markedForRepaint: 1;
    bool m_hasOverlaidWidgets: 1;
    bool m_visibleContentStatusDirty : 1;
    bool m_hasVisibleContent : 1;
    bool m_visibleDescendantStatusDirty : 1;
    bool m_hasVisibleDescendant : 1;
    bool m_inScrollbarRelayout : 1;
    bool m_wasStackingContext : 1; // set to 1 when last style application
    // establised us as a stacking context

    QRect m_visibleRect;

    QRegion m_region; // used by overlaid (non z-order aware) widgets

    Marquee *m_marquee; // Used by layers with overflow:marquee
};

} // namespace
#endif