#include "misc/khtmllayout.h"
#include "misc/loader_client.h"
#include "misc/helper.h"
#include "rendering/render_style.h"
#include "khtml_events.h"
#include "xml/dom_nodeimpl.h"
// Uncomment to turn on incremental repainting.
#define INCREMENTAL_REPAINTING 1
class QPainter;
class QTextStream;
class CSSStyle;
class KHTMLView;
class RenderArena;
#ifndef NDEBUG
#define KHTMLAssert( x ) if( !(x) ) { \
const RenderObject *o = this; while( o->parent() ) o = o->parent(); \
o->printTree(); \
qDebug(" this object = %p", this ); \
assert( false ); \
}
#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;
namespace DOM {
class HTMLAreaElementImpl;
class DOMString;
class DocumentImpl;
class ElementImpl;
class EventImpl;
};
namespace khtml {
class RenderFlow;
class RenderBlock;
class RenderStyle;
class RenderTable;
class CachedObject;
class RenderCanvas;
class RenderText;
class RenderFrameSet;
class RenderLayer;
class InlineBox;
class InlineFlowBox;
class CollapsedBorderValue;
/**
* Base Class for all rendering tree objects.
*/
class RenderObject : public CachedObjectClient
{
public:
// Anonymous objects should pass the document as their node, and they will then automatically be
// marked as anonymous in the constructor.
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 0; }
virtual RenderObject *lastChild() const { return 0; }
virtual RenderLayer* layer() const { return 0; }
RenderLayer* enclosingLayer();
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();
virtual QRect getOverflowClipRect(int tx, int ty) { return QRect(0,0,0,0); }
virtual QRect getClipRect(int tx, int ty) { return QRect(0,0,0,0); }
bool hasClip() { return isPositioned() && style()->hasClip(); }
bool hasOverflowClip() { return style()->hidesOverflow(); }
virtual int getBaselineOfFirstLineBox() { return -1; } // Tables and blocks implement this.
virtual InlineFlowBox* getFirstLineBox() { return 0; } // Tables and blocks implement this.
// Obtains the nearest enclosing block (including this block) that contributes a first-line style to our inline
// children.
virtual RenderBlock* firstLineBlock() const;
virtual void updateFirstLetter();
// Called when an object that was floating or positioned becomes a normal flow object
// again. We have to make sure the render tree updates as needed to accommodate the new
// normal flow object.
void handleDynamicFloatPositionChange();
// This function is a convenience helper for creating an anonymous block that inherits its
// style from this RenderObject.
RenderBlock* createAnonymousBlock();
// Whether or not a positioned element requires normal flow x/y to be computed
// to determine its position.
bool hasStaticX() const;
bool hasStaticY() const;
virtual void setStaticX(short staticX) {};
virtual void setStaticY(int staticY) {};
// RenderObject tree manipulation
//////////////////////////////////////////
virtual bool canHaveChildren() const;
virtual void addChild(RenderObject *newChild, RenderObject *beforeChild = 0);
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);
//////////////////////////////////////////
private:
//////////////////////////////////////////
// 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"; }
#ifndef NDEBUG
QString information() const;
virtual void printTree(int indent=0) const;
virtual void dump(QTextStream *stream, QString ind = "") 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) throw();
public:
RenderArena* renderArena() 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 void setChildrenInline(bool b) { };
virtual RenderFlow* continuation() const;
virtual bool isInlineContinuation() const;
virtual bool isListItem() const { return false; }
virtual bool isListMarker() const { return false; }
virtual bool isCanvas() const { return false; }
bool isRoot() const;
bool isBody() const;
bool isHR() const;
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 isFormElement() const { return false; }
virtual bool isImage() const { return false; }
virtual bool isTextArea() const { return false; }
virtual bool isFrameSet() const { return false; }
virtual bool isApplet() const { return false; }
bool isHTMLMarquee() const;
bool isAnonymous() const { return m_isAnonymous; }
void setIsAnonymous(bool b) { m_isAnonymous = b; }
bool isAnonymousBlock() const { return m_isAnonymous &&
style()->display() == BLOCK &&
style()->styleType() == RenderStyle::NOPSEUDO &&
!isListMarker(); }
bool isFloating() const { return m_floating; }
bool isPositioned() const { return m_positioned; } // absolute or fixed positioning
bool isRelPositioned() const { return m_relPositioned; } // relative positioning
bool isText() const { return m_isText; }
bool isInline() const { return m_inline; } // inline object
bool isCompact() const { return style()->display() == COMPACT; } // compact object
bool isRunIn() const { return style()->display() == RUN_IN; } // run-in object
bool mouseInside() const;
bool isReplaced() const { return m_replaced; } // a "replaced" element (see CSS)
bool shouldPaintBackgroundOrBorder() const { return m_paintBackground; }
bool needsLayout() const { return m_needsLayout || m_normalChildNeedsLayout || m_posChildNeedsLayout; }
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 overhangingContents() const { return m_overhangingContents; }
bool isSelectionBorder() const { return m_isSelectionBorder; }
bool recalcMinMax() const { return m_recalcMinMax; }
RenderStyle* getPseudoStyle(RenderStyle::PseudoId pseudo, RenderStyle* parentStyle = 0) const;
RenderCanvas* canvas() const;
// don't even think about making this method virtual!
DOM::NodeImpl* element() const { return m_isAnonymous ? 0 : m_node; }
DOM::DocumentImpl* document() const { return m_node->getDocument(); }
void setNode(DOM::NodeImpl* node) { m_node = node; }
DOM::NodeImpl* node() const { return m_node; }
/**
* returns the object containing this one. can be different from parent for
* positioned elements
*/
RenderObject *container() const;
void setOverhangingContents(bool p=true);
virtual void markAllDescendantsWithFloatsForLayout(RenderObject* floatToRemove = 0);
void markContainingBlocksForLayout();
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;
RenderObject *root = this;
while( o ) { // ### && !o->m_recalcMinMax ) {
o->m_recalcMinMax = true;
root = o;
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 setIsSelectionBorder(bool b=true) { m_isSelectionBorder = b; }
#ifdef INCREMENTAL_REPAINTING
void scheduleRelayout();
#else
void scheduleRelayout(RenderObject* clippedObj);
#endif
virtual InlineBox* createInlineBox(bool makePlaceHolderBox, bool isRootLineBox);
// for discussion of lineHeight see CSS2 spec
virtual short lineHeight( bool firstLine, bool isRootLineBox=false ) const;
// for the vertical-align property of inline elements
// the difference between this objects baseline position and the lines baseline position.
virtual short verticalPositionHint( bool firstLine ) const;
// the offset of baseline from the top of the object.
virtual short baselinePosition( bool firstLine, bool isRootLineBox=false ) const;
/*
* Paint the object and its children, clipped by (x|y|w|h).
* (tx|ty) is the calculated position of the parent
*/
virtual void paint(QPainter *p, int x, int y, int w, int h, int tx, int ty,
PaintAction paintAction);
virtual void paintObject( QPainter */*p*/, int /*x*/, int /*y*/,
int /*w*/, int /*h*/, int /*tx*/, int /*ty*/,
PaintAction paintAction /*paintAction*/) {}
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);
// RenderBox implements this.
virtual void paintBoxDecorations(QPainter *p,int _x, int _y,
int _w, int _h, int _tx, int _ty) {};
virtual void paintBackgroundExtended(QPainter *p, const QColor &c, CachedImage *bg, int clipy, int cliph,
int _tx, int _ty, int w, int height,
int bleft, int bright) {};
/*
* 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() {}
/*
* 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() {};
// 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;
#if APPLE_CHANGES
// Called recursively to update the absolute positions of all widgets.
virtual void updateWidgetPositions();
#endif
// 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 RenderLayer;
friend class RenderImage;
friend class RenderText;
friend class RenderInline;
friend class RenderObject;
friend class RenderFrameSet;
friend class DOM::HTMLAreaElementImpl;
public:
NodeInfo(bool readonly, bool active)
: m_innerNode(0), m_innerNonSharedNode(0), m_innerURLElement(0), 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;
};
FindSelectionResult checkSelectionPoint(int x, int y, int tx, int ty, DOM::NodeImpl*&, int& offset);
virtual FindSelectionResult checkSelectionPointIgnoringContinuations(int x, int y, int tx, int ty, DOM::NodeImpl*&, int& offset);
virtual bool nodeAtPoint(NodeInfo& info, int x, int y, int tx, int ty,
HitTestAction hitTestAction = HitTestAll, bool inside=false);
// 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() const;
// return just the height of the containing block
virtual int containingBlockHeight() 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; }
// calculate client position of box
virtual bool absolutePosition(int &/*xPos*/, int &/*yPos*/, bool fixed = false);
// 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 normal flow overflow spillage out of the bottom
// of the block (e.g., a that has a 100px tall image inside
// it would have an overflow height of borderTop() + paddingTop() + 100px.
virtual int overflowHeight(bool includeInterior=true) const { return height(); }
virtual int overflowWidth(bool includeInterior=true) const { return width(); }
virtual void setOverflowHeight(int) {}
virtual void setOverflowWidth(int) {}
// IE extensions. Used to calculate offsetWidth/Height. Overridden by inlines (render_flow)
// to return the remaining width on a given line (and the height of a single line). -dwh
virtual short offsetWidth() const { return width(); }
virtual int offsetHeight() const { return height(); }
// IE exxtensions. Also supported by Gecko. We override in render flow to get the
// left and top correct. -dwh
virtual int offsetLeft() const;
virtual int offsetTop() const;
virtual RenderObject* offsetParent() const;
// More IE extensions. clientWidth and clientHeight represent the interior of an object
// excluding border and scrollbar.
short clientWidth() const;
int clientHeight() const;
// scrollWidth/scrollHeight will be the same as clientWidth/clientHeight unless the
// object has overflow:hidden/scroll/auto specified and also has overflow.
short scrollWidth() const;
int scrollHeight() const;
// The following seven functions are used to implement collapsing margins.
// All objects know their maximal positive and negative margins. The
// formula for computing a collapsed margin is |maxPosMargin|-|maxNegmargin|.
// For a non-collapsing, e.g., a leaf element, this formula will simply return
// the margin of the element. Blocks override the maxTopMargin and maxBottomMargin
// methods.
virtual bool isSelfCollapsingBlock() const { return false; }
virtual short collapsedMarginTop() const
{ return maxTopMargin(true)-maxTopMargin(false); }
virtual 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 {
if (positive)
if (marginTop() > 0)
return marginTop();
else
return 0;
else
if (marginTop() < 0)
return 0 - marginTop();
else
return 0;
}
virtual short maxBottomMargin(bool positive) const {
if (positive)
if (marginBottom() > 0)
return marginBottom();
else
return 0;
else
if (marginBottom() < 0)
return 0 - marginBottom();
else
return 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 since table cells override
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 void absoluteRects(QValueList& rects, int _tx, int _ty);
#if APPLE_CHANGES
virtual void addFocusRingRects(QPainter *painter, int _tx, int _ty);
#endif
virtual short minWidth() const { return 0; }
virtual short maxWidth() const { return 0; }
RenderStyle* style() const { return m_style; }
RenderStyle* style( bool firstLine ) const;
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);
virtual void setTable(RenderTable*) {};
// Used by collapsed border tables.
virtual void collectBorders(QValueList& borderStyles);
// Repaint the entire object. Called when, e.g., the color of a border changes, or when a border
// style changes.
void repaint(bool immediate = false);
// Repaint a specific subrectangle within a given object. The rect |r| is in the object's coordinate space.
void repaintRectangle(const QRect& r, bool immediate = false);
#ifdef INCREMENTAL_REPAINTING
// Repaint only if our old bounds and new bounds are different.
virtual void repaintAfterLayoutIfNeeded(const QRect& oldBounds, const QRect& oldFullBounds);
// Repaint only if the object moved.
virtual void repaintDuringLayoutIfMoved(int oldX, int oldY);
// Called to repaint a block's floats.
virtual void repaintFloatingDescendants();
// Called before layout to repaint all dirty children (with selfNeedsLayout() set).
virtual void repaintObjectsBeforeLayout();
bool checkForRepaintDuringLayout() const;
#endif
// Returns the rect that should be repainted whenever this object changes. The rect is in the view's
// coordinate space. This method deals with outlines and overflow.
virtual QRect getAbsoluteRepaintRect();
QRect getAbsoluteRepaintRectWithOutline(int ow);
#ifdef INCREMENTAL_REPAINTING
virtual void getAbsoluteRepaintRectIncludingFloats(QRect& bounds, QRect& boundsWithChildren);
#endif
// Given a rect in the object's coordinate space, this method converts the rectangle to the view's
// coordinate space.
virtual void computeAbsoluteRepaintRect(QRect& r, bool f=false);
virtual unsigned int length() const { return 1; }
bool isFloatingOrPositioned() const { return (isFloating() || isPositioned()); };
virtual bool containsFloats() { return false; }
virtual bool containsFloat(RenderObject* o) { return false; }
virtual bool hasOverhangingFloats() { return false; }
bool avoidsFloats() const;
bool usesLineWidth() const;
// positioning of inline children (bidi)
virtual void position(InlineBox*, int, int, bool) {}
// 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) {}
virtual void cursorPos(int /*offset*/, int &/*_x*/, int &/*_y*/, int &/*height*/);
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 void calcVerticalMargins() {}
void removeFromObjectLists();
virtual void detach();
const QFont &font(bool firstLine) const {
return style( firstLine )->font();
}
const QFontMetrics &fontMetrics(bool firstLine) const {
return style( firstLine )->fontMetrics();
}
// Virtual function helpers for CSS3 Flexible Box Layout
virtual bool isFlexibleBox() const { return false; }
virtual bool isFlexingChildren() const { return false; }
virtual bool isStretchingChildren() const { return false; }
// Convenience, to avoid repeating the code to dig down to get this.
QChar backslashAsCurrencySymbol() const;
virtual void setPixmap(const QPixmap&, const QRect&, CachedImage *);
protected:
virtual void selectionStartEnd(int& spos, int& epos);
virtual void printBoxDecorations(QPainter* /*p*/, int /*_x*/, int /*_y*/,
int /*_w*/, int /*_h*/, int /*_tx*/, int /*_ty*/) {}
virtual QRect viewRect() const;
void remove();
void invalidateVerticalPositions();
short getVerticalPosition( bool firstLine ) const;
virtual void removeLeftoverAnonymousBoxes();
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_posChildNeedsLayout : 1;
bool m_minMaxKnown : 1;
bool m_floating : 1;
bool m_positioned : 1;
bool m_overhangingContents : 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_replaced : 1;
bool m_mouseInside : 1;
bool m_isSelectionBorder : 1;
void arenaDelete(RenderArena *arena, void *objectBase);
// note: do not add unnecessary bitflags, we have 32 bit already!
friend class RenderListItem;
friend class RenderContainer;
friend class RenderCanvas;
};
enum VerticalPositionHint {
PositionTop = -0x4000,
PositionBottom = 0x4000,
PositionUndefined = 0x3fff
};
}; //namespace
#endif