src/rendering/render_object.h

/*
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000-2003 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000-2003 Dirk Mueller (mueller@kde.org)
 *           (C) 2002-2003 Apple Computer, Inc.
 *           (C) 2004 Allan Sandfeld Jensen
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */
#ifndef render_object_h
#define render_object_h

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

#include <QDebug>

#include "xml/dom_docimpl.h"
#include "misc/khtmllayout.h"
#include "misc/loader_client.h"
#include "misc/helper.h"
#include "rendering/render_style.h"
#include "rendering/render_position.h"
#include <QTextStream>

// svg
#include "FloatRect.h"
#include "AffineTransform.h"

using WebCore::FloatRect;
using WebCore::AffineTransform;

class QPainter;
class QTextStream;
template<class Key, class T> class QCache;

#ifndef NDEBUG
#define KHTMLAssert( x ) if( !(x) ) { \
        const RenderObject *o = this; while( o->parent() ) o = o->parent(); \
        o->printTree(); \
        qDebug(" this object = %p", (void*) this); \
        assert( x ); \
    }
#else
#define KHTMLAssert( x )
#endif

/*
 *  The painting of a layer occurs in three distinct phases.  Each phase involves
 *  a recursive descent into the layer's render objects. The first phase is the background phase.
 *  The backgrounds and borders of all blocks are painted.  Inlines are not painted at all.
 *  Floats must paint above block backgrounds but entirely below inline content that can overlap them.
 *  In the foreground phase, all inlines are fully painted.  Inline replaced elements will get all
 *  three phases invoked on them during this phase.
 */

typedef enum {
    PaintActionElementBackground = 0,
    PaintActionChildBackground,
    PaintActionChildBackgrounds,
    PaintActionFloat,
    PaintActionForeground,
    PaintActionOutline,
    PaintActionSelection,
    PaintActionCollapsedTableBorders
} PaintAction;

typedef enum {
    HitTestAll = 0,
    HitTestSelfOnly = 1,
    HitTestChildrenOnly = 2
} HitTestAction;

typedef enum {
    PageBreakNormal = 0, // all rules apply
    PageBreakHarder = 1, // page-break-inside: avoid is ignored
    PageBreakForced = 2  // page-break-after/before: avoid, orphans and widows ignored
} PageBreakLevel;

typedef enum {
    LowPriority = 0,
    NormalPriority = 1,
    HighPriority = 2,
    RealtimePriority = 3
} Priority;

inline PageBreakLevel operator| (PageBreakLevel a, PageBreakLevel b)
{
    if (a == PageBreakForced || b == PageBreakForced) {
        return PageBreakForced;
    }
    if (a == PageBreakHarder || b == PageBreakHarder) {
        return PageBreakHarder;
    }
    return PageBreakNormal;
}

namespace DOM
{
class HTMLAreaElementImpl;
class NodeImpl;
class DocumentImpl;
class ElementImpl;
class EventImpl;
class Selection;
}

namespace khtml
{
class RenderFlow;
class RenderStyle;
class CachedObject;
class RenderObject;
class RenderCanvas;
class RenderText;
class RenderFrameSet;
class RenderArena;
class RenderLayer;
class RenderBlock;
class InlineBox;
class InlineFlowBox;
class CounterNode;
class RenderPosition;

/**
 * Base Class for all rendering tree objects.
 */
class RenderObject : public CachedObjectClient
{
    RenderObject(const RenderObject &);
    RenderObject &operator=(const RenderObject &);
public:
    KHTML_EXPORT static void cleanup();

    RenderObject(DOM::NodeImpl *node);
    virtual ~RenderObject();

    RenderObject *parent() const
    {
        return m_parent;
    }

    RenderObject *previousSibling() const
    {
        return m_previous;
    }
    RenderObject *nextSibling() const
    {
        return m_next;
    }

    virtual RenderObject *firstChild() const
    {
        return nullptr;
    }
    virtual RenderObject *lastChild() const
    {
        return nullptr;
    }

    RenderObject *nextRenderer() const;
    RenderObject *previousRenderer() const;

    RenderObject *nextEditable() const;
    RenderObject *previousEditable() const;

    RenderObject *firstLeafChild() const;
    RenderObject *lastLeafChild() const;

    virtual bool childAllowed() const
    {
        return false;
    }
    virtual int borderTopExtra() const
    {
        return 0;
    }
    virtual int borderBottomExtra() const
    {
        return 0;
    }

    virtual RenderLayer *layer() const
    {
        return nullptr;
    }
    RenderLayer *enclosingLayer() const;
    RenderLayer *enclosingStackingContext() const;
    void addLayers(RenderLayer *parentLayer, RenderObject *newObject);
    void removeLayers(RenderLayer *parentLayer);
    void moveLayers(RenderLayer *oldParent, RenderLayer *newParent);
    RenderLayer *findNextLayer(RenderLayer *parentLayer, RenderObject *startPoint,
                               bool checkParent = true);
    virtual void positionChildLayers() { }
    virtual bool requiresLayer() const
    {
        return isRoot()/* ### */ || isPositioned() || isRelPositioned() || hasOverflowClip() || style()->opacity() < 1.0f;
    }

    virtual QRect overflowClipRect(int /*tx*/, int /*ty*/)
    {
        return QRect(0, 0, 0, 0);
    }
    virtual QRect clipRect(int /*tx*/, int /*ty*/)
    {
        return QRect(0, 0, 0, 0);
    }
    bool hasClip() const
    {
        return isPositioned() &&  style()->hasClip();
    }
    bool hasOverflowClip() const
    {
        return m_hasOverflowClip;
    }

    bool scrollsOverflow() const
    {
        return scrollsOverflowX() || scrollsOverflowY();
    }
    bool scrollsOverflowX() const
    {
        return  hasOverflowClip() && (style()->overflowX() == OSCROLL || style()->overflowX() == OAUTO);
    }
    bool scrollsOverflowY() const
    {
        return  hasOverflowClip() && (style()->overflowY() == OSCROLL || style()->overflowY() == OAUTO);
    }

    virtual int getBaselineOfFirstLineBox()
    {
        return -1;    // Tables and blocks implement this.
    }
    virtual InlineFlowBox *getFirstLineBox()
    {
        return nullptr;    // Tables and blocks implement this.
    }

    // Whether or not a positioned element requires normal flow x/y to be computed
    // to determine its position.
    bool hasStaticX() const
    {
        return style()->left().isAuto() && style()->right().isAuto();
    }
    bool hasStaticY() const
    {
        return style()->top().isAuto() && style()->bottom().isAuto();
    }
    bool isPosWithStaticDim()   const
    {
        return isPositioned() && (hasStaticX() || hasStaticY());
    }

    // Linear tree traversal
    RenderObject *objectBelow() const;
    RenderObject *objectAbove() const;

    // Returns if an object has counter-increment or counter-reset
    bool hasCounter(const DOMString &counter) const;
    // Calculates the value of the counter
    CounterNode *getCounter(const DOMString &counter, bool view = false, bool counters = false);
    // Detaches all counterNodes
    void detachCounters();

protected:
    // Helper functions for counter-cache
    void insertCounter(const DOMString &counter, CounterNode *value);
    CounterNode *lookupCounter(const DOMString &counter) const;

public:
    //////////////////////////////////////////
    // RenderObject tree manipulation
    virtual void addChild(RenderObject *newChild, RenderObject *beforeChild = nullptr);
    virtual void removeChild(RenderObject *oldChild);

    // raw tree manipulation
    virtual RenderObject *removeChildNode(RenderObject *child);
    virtual void appendChildNode(RenderObject *child);
    virtual void insertChildNode(RenderObject *child, RenderObject *before);
    //////////////////////////////////////////

    //////////////////////////////////////////
    // Helper functions. Dangerous to use!
    void setPreviousSibling(RenderObject *previous)
    {
        m_previous = previous;
    }
    void setNextSibling(RenderObject *next)
    {
        m_next = next;
    }
    void setParent(RenderObject *parent)
    {
        m_parent = parent;
    }
    //////////////////////////////////////////

public:
    virtual const char *renderName() const
    {
        return "RenderObject";
    }
#ifdef ENABLE_DUMP
    QString information() const;
    virtual void printTree(int indent = 0) const;
    virtual void dump(QTextStream &stream, const QString &ind = QString()) const;
    void printLineBoxTree() const;
#endif

    static RenderObject *createObject(DOM::NodeImpl *node, RenderStyle *style);

    // 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);

public:
    RenderArena *renderArena() const;
    virtual RenderFlow *continuation() const
    {
        return nullptr;
    }
    virtual bool isInlineContinuation() const
    {
        return false;
    }

    bool isRoot() const
    {
        return m_isRoot && !m_isAnonymous;
    }
    void setIsRoot(bool b)
    {
        m_isRoot = b;
    }
    bool isHR() const;
    // some helper functions...
    virtual bool isRenderBlock() const
    {
        return false;
    }
    virtual bool isRenderInline() const
    {
        return false;
    }
    virtual bool isInlineFlow() const
    {
        return false;
    }
    virtual bool isBlockFlow() const
    {
        return false;
    }
    virtual bool isInlineBlockOrInlineTable() const
    {
        return false;
    }
    virtual bool childrenInline() const
    {
        return false;
    }
    virtual bool isBox() const
    {
        return false;
    }
    virtual bool isRenderReplaced() const
    {
        return false;
    }

    virtual bool isGlyph() const
    {
        return false;
    }
    virtual bool isCounter() const
    {
        return false;
    }
    virtual bool isQuote() const
    {
        return false;
    }
    virtual bool isListItem() const
    {
        return false;
    }
    virtual bool isListMarker() const
    {
        return false;
    }
    virtual bool isCanvas() const
    {
        return false;
    }
    virtual bool isBR() const
    {
        return false;
    }
    virtual bool isTableCell() const
    {
        return false;
    }
    virtual bool isTableRow() const
    {
        return false;
    }
    virtual bool isTableSection() const
    {
        return false;
    }
    virtual bool isTableCol() const
    {
        return false;
    }
    virtual bool isTable() const
    {
        return false;
    }
    virtual bool isWidget() const
    {
        return false;
    }
    virtual bool isBody() const
    {
        return false;
    }
    virtual bool isFormElement() const
    {
        return false;
    }
    virtual bool isFrameSet() const
    {
        return false;
    }
    virtual bool isApplet() const
    {
        return false;
    }
    virtual bool isMedia() const
    {
        return false;
    }

    virtual bool isEditable() const;

    // svg
    virtual bool isSVGRoot() const
    {
        return false;
    }
    virtual bool isRenderPath() const
    {
        return false;
    }
    virtual bool isSVGContainer() const
    {
        return false;
    }
    virtual bool isSVGText() const
    {
        return false;
    }
    virtual bool isSVGHiddenContainer() const
    {
        return false;
    }

    virtual FloatRect relativeBBox(bool includeStroke = false) const;

    virtual AffineTransform localTransform() const;
    virtual AffineTransform absoluteTransform() const;
    // end svg

    bool isHTMLMarquee() const;
    bool isWordBreak() const;

    bool isAnonymous() const
    {
        return m_isAnonymous;
    }
    void setIsAnonymous(bool b)
    {
        m_isAnonymous = b;
    }
    bool isAnonymousBlock() const
    {
        return isAnonymous() && style()->display() == BLOCK && node()->isDocumentNode();
    }
    bool isPseudoAnonymous() const
    {
        return isAnonymous() && !node()->isDocumentNode();
    }

    bool isFloating() const
    {
        return m_floating;
    }
    bool isPositioned() const
    {
        return m_positioned;
    }
    bool isRelPositioned() const
    {
        return m_relPositioned;
    }
    bool isText() const
    {
        return m_isText;
    }
    bool isInline() const
    {
        return m_inline;
    }
    bool isCompact() const
    {
        return style()->display() == COMPACT;    // compact
    }
    bool isRunIn() const
    {
        return style()->display() == RUN_IN;    // run-in object
    }
    bool mouseInside() const;
    bool isDragging() const;
    bool isReplaced() const
    {
        return m_replaced;
    }
    bool isReplacedBlock() const
    {
        return isInline() && isReplaced() && isRenderBlock();
    }
    bool shouldPaintBackgroundOrBorder() const
    {
        return m_paintBackground;
    }
    bool needsLayout() const
    {
        return m_needsLayout || m_normalChildNeedsLayout || m_posChildNeedsLayout;
    }
    bool markedForRepaint() const
    {
        return m_markedForRepaint;
    }
    void setMarkedForRepaint(bool m)
    {
        m_markedForRepaint = m;
    }
    bool selfNeedsLayout() const
    {
        return m_needsLayout;
    }
    bool posChildNeedsLayout() const
    {
        return m_posChildNeedsLayout;
    }
    bool normalChildNeedsLayout() const
    {
        return m_normalChildNeedsLayout;
    }
    bool minMaxKnown() const
    {
        return m_minMaxKnown;
    }
    bool hasFirstLine() const
    {
        return m_hasFirstLine;
    }
    bool isSelectionBorder() const
    {
        return m_isSelectionBorder;
    }
    bool recalcMinMax() const
    {
        return m_recalcMinMax;
    }

    RenderCanvas *canvas() const;
    // don't even think about making this method virtual!
    DOM::DocumentImpl *document() const;
    DOM::NodeImpl *element() const
    {
        return isAnonymous() ? nullptr : m_node;
    }
    DOM::NodeImpl *node() const
    {
        return m_node;
    }

    virtual bool handleEvent(const DOM::EventImpl &)
    {
        return false;
    }

    /**
      * returns the object containing this one. can be different from parent for
      * positioned elements
      */
    RenderObject *container() const;

    void markContainingBlocksForLayout();
    void dirtyFormattingContext(bool checkContainer);
    void repaintDuringLayout();
    void setNeedsLayout(bool b, bool markParents = true);
    void setChildNeedsLayout(bool b, bool markParents = true);
    void setMinMaxKnown(bool b = true)
    {
        m_minMaxKnown = b;
        if (!b) {
            RenderObject *o = this;
            while (o) {  // ### && !o->m_recalcMinMax ) {
                o->m_recalcMinMax = true;
                o = o->m_parent;
            }
        }
    }
    void setNeedsLayoutAndMinMaxRecalc()
    {
        setMinMaxKnown(false);
        setNeedsLayout(true);
    }
    void setPositioned(bool b = true)
    {
        m_positioned = b;
    }
    void setRelPositioned(bool b = true)
    {
        m_relPositioned = b;
    }
    void setFloating(bool b = true)
    {
        m_floating = b;
    }
    void setInline(bool b = true)
    {
        m_inline = b;
    }
    void setMouseInside(bool b = true)
    {
        m_mouseInside = b;
    }
    void setShouldPaintBackgroundOrBorder(bool b = true)
    {
        m_paintBackground = b;
    }
    void setRenderText()
    {
        m_isText = true;
    }
    void setReplaced(bool b = true)
    {
        m_replaced = b;
    }
    void setHasOverflowClip(bool b = true)
    {
        m_hasOverflowClip = b;
    }
    void setIsSelectionBorder(bool b = true)
    {
        m_isSelectionBorder = b;
    }

    void scheduleRelayout(RenderObject *clippedObj = nullptr);

    void updateBackgroundImages(RenderStyle *oldStyle);

    virtual InlineBox *createInlineBox(bool makePlaceHolderBox, bool isRootLineBox);
    virtual void removeInlineBox(InlineBox * /*box*/) {}

    virtual InlineBox *inlineBox(long offset = 0);
    virtual short lineHeight(bool firstLine) const;
    virtual short verticalPositionHint(bool firstLine) const;
    virtual short baselinePosition(bool firstLine) const;
    short getVerticalPosition(bool firstLine, RenderObject *ref = nullptr) const;

    /*
     * Print the object and its children, clipped by (x|y|w|h).
     * (tx|ty) is the calculated position of the parent
     */
    struct PaintInfo {
        PaintInfo(QPainter *_p, const QRect &_r, PaintAction _phase)
            : p(_p), r(_r), phase(_phase), outlineObjects(nullptr) {}
        ~PaintInfo()
        {
            delete outlineObjects;
        }
        QPainter *p;
        QRect     r;
        PaintAction phase;
        QList<RenderFlow *> *outlineObjects; // used to list which outlines should be painted by a block with inline children
    };
    virtual void paint(PaintInfo &i, int tx, int ty);

    void calcBorderRadii(QPoint &topLeftRadii, QPoint &topRightRadii, QPoint &bottomLeftRadii, QPoint &bottomRightRadii, int w, int h) const;

    void drawBorderArc(QPainter *p, int x, int y, float horThickness, float vertThickness,
                       const QPoint &radius, int angleStart, int angleSpan, const QBrush &brush,
                       const QColor &textColor, EBorderStyle style, qreal *dashOffset = nullptr) const;

    void paintBorder(QPainter *p, int _tx, int _ty, int w, int h, const RenderStyle *style, bool begin = true, bool end = true);
    void paintOutline(QPainter *p, int _tx, int _ty, int w, int h, const RenderStyle *style);

    virtual void paintBoxDecorations(PaintInfo &, int /*_tx*/, int /*_ty*/) {}

    virtual void paintBackgroundExtended(QPainter * /*p*/, const QColor & /*c*/, const BackgroundLayer * /*bgLayer*/,
                                         QRect /*clipr*/, int /*_tx*/, int /*_ty*/,
                                         int /*w*/, int /*height*/, int /*bleft*/, int /*bright*/, int /*pleft*/, int /*pright*/,
                                         int /*btop*/, int /*bbottom*/, int /*ptop*/, int /*pbottom*/) {}

    /*
     * This function calculates the minimum & maximum width that the object
     * can be set to.
     *
     * when the Element calls setMinMaxKnown(true), calcMinMaxWidth() will
     * be no longer called.
     *
     * when a element has a fixed size, m_minWidth and m_maxWidth should be
     * set to the same value. This has the special meaning that m_width,
     * contains the actual value.
     *
     * assumes calcMinMaxWidth has already been called for all children.
     */
    virtual void calcMinMaxWidth() { }

    /*
     * Does the min max width recalculations after changes.
     */
    void recalcMinMaxWidths();

    /*
     * Calculates the actual width of the object (only for non inline
     * objects)
     */
    virtual void calcWidth() {}

    /*
     * Calculates the actual width of the object (only for non inline
     * objects)
     */
    virtual void calcHeight() {}

    /*
     * This function should cause the Element to calculate its
     * width and height and the layout of its content
     *
     * when the Element calls setNeedsLayout(false), layout() is no
     * longer called during relayouts, as long as there is no
     * style sheet change. When that occurs, m_needsLayout will be
     * set to true and the Element receives layout() calls
     * again.
     */
    virtual void layout() = 0;

    /* This function performs a layout only if one is needed. */
    void layoutIfNeeded()
    {
        if (needsLayout()) {
            layout();
        }
    }

    // used for element state updates that can not be fixed with a
    // repaint and do not need a relayout
    virtual void updateFromElement() {}

    // Called immediately after render-object is inserted
    virtual void attach()
    {
        m_attached = true;
    }
    bool attached()
    {
        return m_attached;
    }
    // The corresponding closing element has been parsed. ### remove me
    virtual void close() { }

    virtual int availableHeight() const
    {
        return 0;
    }

    // Whether or not the element shrinks to its max width (rather than filling the width
    // of a containing block).  HTML4 buttons, legends, and floating/compact elements do this.
    bool sizesToMaxWidth() const;

    /*
     * NeesPageClear indicates the object crossed a page-break but could not break itself and now
     * needs to be moved clear by its parent.
     */
    void setNeedsPageClear(bool b = true)
    {
        m_needsPageClear = b;
    }
    virtual bool needsPageClear() const
    {
        return m_needsPageClear;
    }

    /*
     * ContainsPageBreak indicates the object contains a clean page-break.
     * ### should be removed and replaced with (crossesPageBreak && !needsPageClear)
     */
    void setContainsPageBreak(bool b = true)
    {
        m_containsPageBreak = b;
    }
    virtual bool containsPageBreak() const
    {
        return m_containsPageBreak;
    }

    virtual int pageTopAfter(int y) const
    {
        if (parent()) {
            return parent()->pageTopAfter(y);
        } else {
            return 0;
        }
    }

    virtual int crossesPageBreak(int top, int bottom) const
    {
        if (parent()) {
            return parent()->crossesPageBreak(top, bottom);
        } else {
            return 0;
        }
    }

    // Checks if a page-break before child is possible at the given page-break level
    // false means the child should attempt the break self.
    virtual bool canClear(RenderObject * /*child*/, PageBreakLevel level)
    {
        if (parent()) {
            return parent()->canClear(this, level);
        } else {
            return false;
        }
    }

    void setAfterPageBreak(bool b = true)
    {
        m_afterPageBreak = b;
    }
    void setBeforePageBreak(bool b = true)
    {
        m_beforePageBreak = b;
    }
    virtual bool afterPageBreak() const
    {
        return m_afterPageBreak;
    }
    virtual bool beforePageBreak() const
    {
        return m_beforePageBreak;
    }

    // does a query on the rendertree and finds the innernode
    // and overURL for the given position
    // if readonly == false, it will recalc hover styles accordingly
    class NodeInfo
    {
        friend class RenderImage;
        friend class RenderFlow;
        friend class RenderInline;
        friend class RenderText;
        friend class RenderWidget;
        friend class RenderObject;
        friend class RenderFrameSet;
        friend class RenderLayer;
        friend class DOM::HTMLAreaElementImpl;
    public:
        NodeInfo(bool readonly, bool active)
            : m_innerNode(nullptr), m_innerNonSharedNode(nullptr), m_innerURLElement(nullptr), m_readonly(readonly), m_active(active)
        { }

        DOM::NodeImpl *innerNode() const
        {
            return m_innerNode;
        }
        DOM::NodeImpl *innerNonSharedNode() const
        {
            return m_innerNonSharedNode;
        }
        DOM::NodeImpl *URLElement() const
        {
            return m_innerURLElement;
        }
        bool readonly() const
        {
            return m_readonly;
        }
        bool active() const
        {
            return m_active;
        }

    private:
        void setInnerNode(DOM::NodeImpl *n)
        {
            m_innerNode = n;
        }
        void setInnerNonSharedNode(DOM::NodeImpl *n)
        {
            m_innerNonSharedNode = n;
        }
        void setURLElement(DOM::NodeImpl *n)
        {
            m_innerURLElement = n;
        }

        DOM::NodeImpl *m_innerNode;
        DOM::NodeImpl *m_innerNonSharedNode;
        DOM::NodeImpl *m_innerURLElement;
        bool m_readonly;
        bool m_active;
    };

    /** contains stateful information for a checkSelectionPoint call
     */
    struct SelPointState {
        /** last node that was before the current position */
        DOM::NodeImpl *m_lastNode;
        /** offset of last node */
        long m_lastOffset;
        /** true when the last node had the result SelectionAfterInLine */
        bool m_afterInLine;

        SelPointState() : m_lastNode(nullptr), m_lastOffset(0), m_afterInLine(false)
        {}
    };

#if 0
    virtual FindSelectionResult checkSelectionPoint(int _x, int _y, int _tx, int _ty,
            DOM::NodeImpl *&, int &offset,
            SelPointState &);
#endif
    virtual bool nodeAtPoint(NodeInfo &info, int x, int y, int tx, int ty, HitTestAction, bool inside = false);
    void setInnerNode(NodeInfo &info);

    // Position/Selection stuff
    virtual RenderPosition positionForCoordinates(int x, int y);

    // set the style of the object.
    virtual void setStyle(RenderStyle *style);

    // returns the containing block level element for this element.
    RenderBlock *containingBlock() const;

    // return just the width of the containing block
    virtual short containingBlockWidth(RenderObject *providedCB = nullptr) const;
    // return just the height of the containing block
    virtual int containingBlockHeight(RenderObject *providedCB = nullptr) const;

    // size of the content area (box size minus padding/border)
    virtual short contentWidth() const
    {
        return 0;
    }
    virtual int contentHeight() const
    {
        return 0;
    }

    // intrinsic extend of replaced elements. undefined otherwise
    virtual short intrinsicWidth() const
    {
        return 0;
    }
    virtual int intrinsicHeight() const
    {
        return 0;
    }

    // relative to parent node
    virtual void setPos(int /*xPos*/, int /*yPos*/) { }
    virtual void setWidth(int /*width*/) { }
    virtual void setHeight(int /*height*/) { }

    virtual int xPos() const
    {
        return 0;
    }
    virtual int yPos() const
    {
        return 0;
    }

    /** the position of the object from where it begins drawing, including
     * its negative overflow
     */
    int effectiveXPos() const
    {
        return xPos() + (hasOverflowClip() ? 0 : overflowLeft());
    }

    /** the position of the object from where it begins drawing, including
     * its negative overflow
     */
    int effectiveYPos() const
    {
        return yPos() + (hasOverflowClip() ? -borderTopExtra() : qMin(overflowTop(), -borderTopExtra()));
    }

    /** Leftmost coordinate of this inline element relative to containing
     * block. Always zero for non-inline elements.
     */
    virtual int inlineXPos() const
    {
        return 0;
    }
    /** Topmost coordinate of this inline element relative to containing
     * block. Always zero for non-inline elements.
     */
    virtual int inlineYPos() const
    {
        return 0;
    }

    // calculate client position of box
    virtual bool absolutePosition(int &/*xPos*/, int &/*yPos*/, bool fixed = false) const;

    // width and height are without margins but include paddings and borders
    virtual short width() const
    {
        return 0;
    }
    virtual int height() const
    {
        return 0;
    }

    // The height of a block when you include overflow spillage out of
    // the bottom of the block (e.g., a <div style="height:25px"> that
    // has a 100px tall image inside it would have an overflow height
    // of borderTop() + paddingTop() + 100px.
    virtual int overflowHeight() const
    {
        return height();
    }
    virtual int overflowWidth() const
    {
        return width();
    }
    // how much goes over the left hand side (0 or a negative number)
    virtual int overflowTop() const
    {
        return 0;
    }
    virtual int overflowLeft() const
    {
        return 0;
    }

    /**
     * Returns the height that is effectively considered when contemplating the
     * object as a whole -- usually the overflow height, or the height if clipped.
     */
    int effectiveHeight() const
    {
        return hasOverflowClip() ? height() + borderTopExtra() + borderBottomExtra() :
               qMax(overflowHeight() - overflowTop(),  height() + borderTopExtra() + borderBottomExtra());
    }
    /**
     * Returns the width that is effectively considered when contemplating the
     * object as a whole -- usually the overflow width, or the width if clipped.
     */
    int effectiveWidth() const
    {
        return hasOverflowClip() ? width() : overflowWidth() - overflowLeft();
    }

    QRectF clientRectToViewport(const QRectF &rect);
    virtual QList< QRectF > getClientRects();

    // IE extensions, heavily used in ECMA
    virtual short offsetWidth() const
    {
        return width();
    }
    virtual int offsetHeight() const
    {
        return height() + borderTopExtra() + borderBottomExtra();
    }
    virtual int offsetLeft() const;
    virtual int offsetTop() const;
    virtual RenderObject *offsetParent() const;
    int clientLeft() const;
    int clientTop() const;
    short clientWidth() const;
    int clientHeight() const;
    virtual short scrollWidth() const;
    virtual int scrollHeight() const;

    virtual bool isSelfCollapsingBlock() const
    {
        return false;
    }
    short collapsedMarginTop() const
    {
        return maxTopMargin(true) - maxTopMargin(false);
    }
    short collapsedMarginBottom() const
    {
        return maxBottomMargin(true) - maxBottomMargin(false);
    }

    virtual bool isTopMarginQuirk() const
    {
        return false;
    }
    virtual bool isBottomMarginQuirk() const
    {
        return false;
    }
    virtual short maxTopMargin(bool positive) const
    {
        return positive ? qMax(int(marginTop()), 0) : - qMin(int(marginTop()), 0);
    }
    virtual short maxBottomMargin(bool positive) const
    {
        return positive ? qMax(int(marginBottom()), 0) : - qMin(int(marginBottom()), 0);
    }

    virtual short marginTop() const
    {
        return 0;
    }
    virtual short marginBottom() const
    {
        return 0;
    }
    virtual short marginLeft() const
    {
        return 0;
    }
    virtual short marginRight() const
    {
        return 0;
    }

    virtual int paddingTop() const;
    virtual int paddingBottom() const;
    virtual int paddingLeft() const;
    virtual int paddingRight() const;

    virtual int borderTop() const
    {
        return style()->borderTopWidth();
    }
    virtual int borderBottom() const
    {
        return style()->borderBottomWidth();
    }
    virtual int borderLeft() const
    {
        return style()->borderLeftWidth();
    }
    virtual int borderRight() const
    {
        return style()->borderRightWidth();
    }

    virtual short minWidth() const
    {
        return 0;
    }
    virtual int maxWidth() const
    {
        return 0;
    }

    RenderStyle *style() const
    {
        return m_style;
    }
    RenderStyle *style(bool firstLine) const
    {
        RenderStyle *s = m_style;
        if (firstLine && hasFirstLine()) {
            RenderStyle *pseudoStyle  = style()->getPseudoStyle(RenderStyle::FIRST_LINE);
            if (pseudoStyle) {
                s = pseudoStyle;
            }
        }
        return s;
    }

    void getTextDecorationColors(int decorations, QColor &underline, QColor &overline,
                                 QColor &linethrough, bool quirksMode = false);

    enum BorderSide {
        BSTop, BSBottom, BSLeft, BSRight
    };
    void drawBorder(QPainter *p, int x1, int y1, int x2, int y2, BorderSide s,
                    QColor c, const QColor &textcolor, EBorderStyle style,
                    int adjbw1, int adjbw2, bool invalidisInvert = false, qreal *dashOffset = nullptr);

    // Used by collapsed border tables.
    virtual void collectBorders(QList<CollapsedBorderValue> &borderStyles);

    // force a complete repaint
    virtual void repaint(Priority p = NormalPriority)
    {
        if (m_parent) {
            m_parent->repaint(p);
        }
    }
    virtual void repaintRectangle(int x, int y, int w, int h, Priority p = NormalPriority, bool f = false);

    virtual unsigned int length() const
    {
        return 1;
    }

    virtual bool isHidden() const
    {
        return isFloating() || isPositioned();
    }

    // Special objects are objects that are neither really inline nor blocklevel
    bool isFloatingOrPositioned() const
    {
        return (isFloating() || isPositioned());
    }
    virtual bool hasOverhangingFloats() const
    {
        return false;
    }
    virtual bool hasFloats() const
    {
        return false;
    }
    virtual bool containsFloat(RenderObject * /*o*/) const
    {
        return false;
    }
    virtual void markAllDescendantsWithFloatsForLayout(RenderObject * /*floatToRemove*/ = nullptr) {}

    bool flowAroundFloats() const;
    bool usesLineWidth() const;

    // positioning of inline children (bidi)
    virtual void position(InlineBox *, int, int, bool) {}
//    virtual void position(int, int, int, int, int, bool, bool, int) {}

    // Applied as a "slop" to dirty rect checks during the outline painting phase's dirty-rect checks.
    int maximalOutlineSize(PaintAction p) const;

    enum SelectionState {
        SelectionNone,
        SelectionStart,
        SelectionInside,
        SelectionEnd,
        SelectionBoth
    };

    virtual SelectionState selectionState() const
    {
        return SelectionNone;
    }
    virtual void setSelectionState(SelectionState) {}
    bool shouldSelect() const;
    virtual bool isPointInsideSelection(int x, int y, const DOM::Selection &) const;

    DOM::NodeImpl *draggableNode(bool dhtmlOK, bool uaOK, bool &dhtmlWillDrag) const;

    /**
     * Flags which influence the appearance and position
     * @param CFOverride input overrides existing character, caret should be
     *      cover the whole character
     * @param CFOutside coordinates are to be interpreted outside of the
     *      render object
     * @param CFOutsideEnd coordinates are to be interpreted at the outside
     *      end of the render object (only valid if CFOutside is also set)
     */
    enum CaretFlags { CFOverride = 0x01, CFOutside = 0x02, CFOutsideEnd = 0x04 };

    /**
     * Returns the content coordinates of the caret within this render object.
     * @param offset zero-based offset determining position within the render object.
     * @param flags combination of enum CaretFlags
     * @param _x returns the left coordinate
     * @param _y returns the top coordinate
     * @param width returns the caret's width
     * @param height returns the caret's height
     */
    virtual void caretPos(int offset, int flags, int &_x, int &_y, int &width, int &height) const;

    // returns the lowest position of the lowest object in that particular object.
    // This 'height' is relative to the topleft of the margin box of the object.
    // Implemented in RenderFlow.
    virtual int lowestPosition(bool /*includeOverflowInterior*/ = true, bool /*includeSelf*/ = true) const
    {
        return 0;
    }
    virtual int rightmostPosition(bool /*includeOverflowInterior*/ = true, bool /*includeSelf*/ = true) const
    {
        return 0;
    }
    virtual int leftmostPosition(bool /*includeOverflowInterior*/ = true, bool /*includeSelf*/ = true) const
    {
        return 0;
    }
    virtual int highestPosition(bool /*includeOverflowInterior*/ = true, bool /*includeSelf*/ = true) const
    {
        return 0;
    }

    // recursively invalidate current layout
    // unused: void invalidateLayout();

    virtual void calcVerticalMargins() {}
    void removeFromObjectLists();
    void setInPosObjectList(bool b = true)
    {
        m_inPosObjectList = b;
    }
    bool inPosObjectList() const
    {
        return m_inPosObjectList;
    }

    virtual void deleteInlineBoxes(RenderArena *arena = nullptr)
    {
        (void)arena;
    }
    virtual void dirtyInlineBoxes(bool /*fullLayout*/, bool /*isRootLineBox*/ = false) {}
    virtual void dirtyLinesFromChangedChild(RenderObject *) {}
    virtual void detach();

    bool documentBeingDestroyed() const
    {
        return !document()->renderer();
    }

    void setDoNotDelete(bool b)
    {
        m_doNotDelete = b;
    }
    bool doNotDelete() const
    {
        return m_doNotDelete;
    }

    const QFont &font(bool firstLine) const
    {
        return style(firstLine)->font();
    }

    const QFontMetrics &fontMetrics(bool firstLine) const
    {
        return style(firstLine)->fontMetrics();
    }

    /** returns the lowest possible value the caret offset may have to
     * still point to a valid position.
     *
     * Returns 0 by default.
     */
    virtual long caretMinOffset() const;
    /** returns the highest possible value the caret offset may have to
     * still point to a valid position.
     *
     * Returns 0 by default, as generic elements are considered to have no
     * width.
     */
    virtual long caretMaxOffset() const;
    virtual unsigned long caretMaxRenderedOffset() const;

    void updatePixmap(const QRect &, CachedImage *) override;

    QRegion visibleFlowRegion(int x, int y) const;

    virtual void removeSuperfluousAnonymousBlockChild(RenderObject *) {}

    // Unregisters from parent but does not destroy
    void remove();
protected:
    virtual void selectionStartEnd(int &spos, int &epos);

    virtual QRect viewRect() const;
    void setDetached()
    {
        m_attached = false;
    }
    void invalidateVerticalPosition();
    bool attemptDirectLayerTranslation();
    void updateWidgetMasks();

    void arenaDelete(RenderArena *arena);

private:
    RenderStyle *m_style;
    DOM::NodeImpl *m_node;
    RenderObject *m_parent;
    RenderObject *m_previous;
    RenderObject *m_next;

    short m_verticalPosition;

    bool m_needsLayout               : 1;
    bool m_normalChildNeedsLayout    : 1;
    bool m_markedForRepaint          : 1;
    bool m_posChildNeedsLayout       : 1;

    bool m_minMaxKnown               : 1;
    bool m_floating                  : 1;

    bool m_positioned                : 1;
    bool m_relPositioned             : 1;
    bool m_paintBackground           : 1; // if the box has something to paint in the
    // background painting phase (background, border, etc)

    bool m_isAnonymous               : 1;
    bool m_recalcMinMax          : 1;
    bool m_isText                    : 1;
    bool m_inline                    : 1;
    bool m_attached                  : 1;

    bool m_replaced                  : 1;
    bool m_mouseInside               : 1;
    bool m_hasFirstLine              : 1;
    bool m_isSelectionBorder         : 1;

    bool m_isRoot                    : 1;

    bool m_beforePageBreak           : 1;
    bool m_afterPageBreak            : 1;

    bool m_needsPageClear            : 1;
    bool m_containsPageBreak         : 1;

    bool m_hasOverflowClip           : 1;
    bool m_inPosObjectList           : 1;

    bool m_doNotDelete               : 1; // This object should not be auto-deleted

    // ### we have 16 + 26 bits.

    static QCache<quint64, QPixmap> *s_dashedLineCache;

    void arenaDelete(RenderArena *arena, void *objectBase);

    friend class RenderLayer;
    friend class RenderListItem;
    friend class RenderContainer;
    friend class RenderCanvas;
};

enum VerticalPositionHint {
    PositionTop = -0x4000,
    PositionBottom = 0x4000,
    PositionUndefined = 0x3fff
};

} //namespace
#endif