/*

 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)

 *           (C) 1999 Antti Koivisto (koivisto@kde.org)

 *           (C) 2007 David Smith (catfish.man@gmail.com)

 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.

 *

 * 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 RenderBlock_h

#define RenderBlock_h

#include "DeprecatedPtrList.h"

#include "GapRects.h"

#include "RenderBox.h"

#include "RenderLineBoxList.h"

#include "RootInlineBox.h"

#include <wtf/ListHashSet.h>

namespace WebCore {

class InlineIterator;

class RenderInline;

class RootInlineBox;

struct BidiRun;

template <class Iterator, class Run> class BidiResolver;

template <class Iterator> class MidpointState;

typedef BidiResolver<InlineIterator, BidiRun> InlineBidiResolver;

typedef MidpointState<InlineIterator> LineMidpointState;

enum CaretType { CursorCaret, DragCaret };

class RenderBlock : public RenderBox {

public:

    RenderBlock(Node*);

    virtual ~RenderBlock();

    const RenderObjectChildList* children() const { return &m_children; }

    RenderObjectChildList* children() { return &m_children; }

    virtual void destroy();

    // These two functions are overridden for inline-block.

    virtual int lineHeight(bool firstLine, bool isRootLineBox = false) const;

    virtual int baselinePosition(bool firstLine, bool isRootLineBox = false) const;

    RenderLineBoxList* lineBoxes() { return &m_lineBoxes; }

    const RenderLineBoxList* lineBoxes() const { return &m_lineBoxes; }

    InlineFlowBox* firstLineBox() const { return m_lineBoxes.firstLineBox(); }

    InlineFlowBox* lastLineBox() const { return m_lineBoxes.lastLineBox(); }

    void deleteLineBoxTree();

    virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0);

    virtual void removeChild(RenderObject*);

    virtual void layoutBlock(bool relayoutChildren);

    void insertPositionedObject(RenderBox*);

    void removePositionedObject(RenderBox*);

    void removePositionedObjects(RenderBlock*);

    void addPercentHeightDescendant(RenderBox*);

    static void removePercentHeightDescendant(RenderBox*);

    HashSet<RenderBox*>* percentHeightDescendants() const;

    RootInlineBox* createAndAppendRootInlineBox();

    bool generatesLineBoxesForInlineChild(RenderObject*, bool isLineEmpty = true, bool previousLineBrokeCleanly = true);

    void markAllDescendantsWithFloatsForLayout(RenderBox* floatToRemove = 0, bool inLayout = true);

    void markPositionedObjectsForLayout();

    bool containsFloats() { return m_floatingObjects && !m_floatingObjects->isEmpty(); }

    bool containsFloat(RenderObject*);

    IntRect floatRect() const;

    int lineWidth(int y, bool firstLine) const;

    virtual int lowestPosition(bool includeOverflowInterior = true, bool includeSelf = true) const;

    virtual int rightmostPosition(bool includeOverflowInterior = true, bool includeSelf = true) const;

    virtual int leftmostPosition(bool includeOverflowInterior = true, bool includeSelf = true) const;

    int rightOffset(int y, bool firstLine) const { return rightRelOffset(y, rightOffset(), firstLine); }

    int leftOffset(int y, bool firstLine) const { return leftRelOffset(y, leftOffset(), firstLine); }

    virtual VisiblePosition positionForPoint(const IntPoint&);

    // Block flows subclass availableWidth to handle multi column layout (shrinking the width available to children when laying out.)

    virtual int availableWidth() const;

    RootInlineBox* firstRootBox() const { return static_cast<RootInlineBox*>(firstLineBox()); }

    RootInlineBox* lastRootBox() const { return static_cast<RootInlineBox*>(lastLineBox()); }

    bool containsNonZeroBidiLevel() const;

    virtual void setSelectionState(SelectionState s);

    GapRects selectionGapRectsForRepaint(RenderBoxModelObject* repaintContainer);

    IntRect fillLeftSelectionGap(RenderObject* selObj, int xPos, int yPos, int height, RenderBlock* rootBlock, 

                                 int blockX, int blockY, int tx, int ty, const PaintInfo*);

    IntRect fillRightSelectionGap(RenderObject* selObj, int xPos, int yPos, int height, RenderBlock* rootBlock,

                                  int blockX, int blockY, int tx, int ty, const PaintInfo*);

    IntRect fillHorizontalSelectionGap(RenderObject* selObj, int xPos, int yPos, int width, int height, const PaintInfo*);

    void getHorizontalSelectionGapInfo(SelectionState, bool& leftGap, bool& rightGap);

    // Helper methods for computing line counts and heights for line counts.

    RootInlineBox* lineAtIndex(int);

    int lineCount();

    int heightForLineCount(int);

    void clearTruncation();

    void adjustRectForColumns(IntRect&) const;

    void addContinuationWithOutline(RenderInline*);

    RenderInline* inlineContinuation() const { return m_inlineContinuation; }

    void setInlineContinuation(RenderInline* c) { m_inlineContinuation = c; }

    // This function is a convenience helper for creating an anonymous block that inherits its

    // style from this RenderBlock.

    RenderBlock* createAnonymousBlock(bool isFlexibleBox = false) const;

protected:

    int maxTopPosMargin() const { return m_maxMargin ? m_maxMargin->m_topPos : MaxMargin::topPosDefault(this); }

    int maxTopNegMargin() const { return m_maxMargin ? m_maxMargin->m_topNeg : MaxMargin::topNegDefault(this); }

    int maxBottomPosMargin() const { return m_maxMargin ? m_maxMargin->m_bottomPos : MaxMargin::bottomPosDefault(this); }

    int maxBottomNegMargin() const { return m_maxMargin ? m_maxMargin->m_bottomNeg : MaxMargin::bottomNegDefault(this); }

    void setMaxTopMargins(int pos, int neg);

    void setMaxBottomMargins(int pos, int neg);

    void initMaxMarginValues()

    {

        if (m_maxMargin) {

            m_maxMargin->m_topPos = MaxMargin::topPosDefault(this);

            m_maxMargin->m_topNeg = MaxMargin::topNegDefault(this);

            m_maxMargin->m_bottomPos = MaxMargin::bottomPosDefault(this);

            m_maxMargin->m_bottomNeg = MaxMargin::bottomNegDefault(this);

        }

    }

    virtual void layout();

    void layoutPositionedObjects(bool relayoutChildren);

    virtual void paint(PaintInfo&, int tx, int ty);

    virtual void paintObject(PaintInfo&, int tx, int ty);

    int rightRelOffset(int y, int fixedOffset, bool applyTextIndent = true, int* heightRemaining = 0) const;

    int leftRelOffset(int y, int fixedOffset, bool applyTextIndent = true, int* heightRemaining = 0) const;

    virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);

    virtual void calcPrefWidths();

    virtual int firstLineBoxBaseline() const;

    virtual int lastLineBoxBaseline() const;

    virtual void updateFirstLetter();

    virtual void updateHitTestResult(HitTestResult&, const IntPoint&);

    // Delay update scrollbar until finishDelayRepaint() will be

    // called. This function is used when a flexbox is laying out its

    // descendant. If multiple calls are made to startDelayRepaint(),

    // finishDelayRepaint() will do nothing until finishDelayRepaint()

    // is called the same number of times.

    static void startDelayUpdateScrollInfo();

    static void finishDelayUpdateScrollInfo();

    virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle);

    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);

    virtual bool hasLineIfEmpty() const;

    bool layoutOnlyPositionedObjects();

private:

    virtual RenderObjectChildList* virtualChildren() { return children(); }

    virtual const RenderObjectChildList* virtualChildren() const { return children(); }

    virtual const char* renderName() const;

    virtual bool isRenderBlock() const { return true; }

    virtual bool isBlockFlow() const { return (!isInline() || isReplaced()) && !isTable(); }

    virtual bool isInlineBlockOrInlineTable() const { return isInline() && isReplaced(); }

    void makeChildrenNonInline(RenderObject* insertionPoint = 0);

    virtual void removeLeftoverAnonymousBlock(RenderBlock* child);

    virtual void dirtyLinesFromChangedChild(RenderObject* child) { m_lineBoxes.dirtyLinesFromChangedChild(this, child); }

    virtual bool isSelfCollapsingBlock() const;

    virtual int maxTopMargin(bool positive) const { return positive ? maxTopPosMargin() : maxTopNegMargin(); }

    virtual int maxBottomMargin(bool positive) const { return positive ? maxBottomPosMargin() : maxBottomNegMargin(); }

    virtual void repaintOverhangingFloats(bool paintAllDescendants);

    void layoutBlockChildren(bool relayoutChildren, int& maxFloatBottom);

    void layoutInlineChildren(bool relayoutChildren, int& repaintTop, int& repaintBottom);

    virtual void positionListMarker() { }

    virtual void borderFitAdjust(int& x, int& w) const; // Shrink the box in which the border paints if border-fit is set.

    virtual void updateBeforeAfterContent(PseudoId);

    virtual RootInlineBox* createRootInlineBox(); // Subclassed by SVG and Ruby.

    // Called to lay out the legend for a fieldset.

    virtual RenderObject* layoutLegend(bool /*relayoutChildren*/) { return 0; }

    struct FloatWithRect {

        FloatWithRect(RenderBox* f)

            : object(f)

            , rect(IntRect(f->x() - f->marginLeft(), f->y() - f->marginTop(), f->width() + f->marginLeft() + f->marginRight(), f->height() + f->marginTop() + f->marginBottom()))

            , everHadLayout(f->m_everHadLayout)

        {

        }

        RenderBox* object;

        IntRect rect;

        bool everHadLayout;

    };

    // The following functions' implementations are in RenderBlockLineLayout.cpp.

    void bidiReorderLine(InlineBidiResolver&, const InlineIterator& end, bool previousLineBrokeCleanly);

    RootInlineBox* determineStartPosition(bool& firstLine, bool& fullLayout, bool& previousLineBrokeCleanly,

                                          InlineBidiResolver&, Vector<FloatWithRect>& floats, unsigned& numCleanFloats);

    RootInlineBox* determineEndPosition(RootInlineBox* startBox, InlineIterator& cleanLineStart,

                                        BidiStatus& cleanLineBidiStatus,

                                        int& yPos);

    bool matchedEndLine(const InlineBidiResolver&, const InlineIterator& endLineStart, const BidiStatus& endLineStatus,

                        RootInlineBox*& endLine, int& endYPos, int& repaintBottom, int& repaintTop);

    void skipTrailingWhitespace(InlineIterator&, bool isLineEmpty, bool previousLineBrokeCleanly);

    int skipLeadingWhitespace(InlineBidiResolver&, bool firstLine, bool isLineEmpty, bool previousLineBrokeCleanly);

    void fitBelowFloats(int widthToFit, bool firstLine, int& availableWidth);

    InlineIterator findNextLineBreak(InlineBidiResolver&, bool firstLine, bool& isLineEmpty, bool& previousLineBrokeCleanly, EClear* clear = 0);

    RootInlineBox* constructLine(unsigned runCount, BidiRun* firstRun, BidiRun* lastRun, bool firstLine, bool lastLine, RenderObject* endObject);

    InlineFlowBox* createLineBoxes(RenderObject*, bool firstLine);

    void computeHorizontalPositionsForLine(RootInlineBox*, bool firstLine, BidiRun* firstRun, BidiRun* trailingSpaceRun, bool reachedEnd);

    void computeVerticalPositionsForLine(RootInlineBox*, BidiRun*);

    void deleteEllipsisLineBoxes();

    void checkLinesForTextOverflow();

    void addOverflowFromInlineChildren();

    // End of functions defined in RenderBlockLineLayout.cpp.

    void addOverflowFromBlockChildren();

    void addOverflowFromFloats();

    void paintFloats(PaintInfo&, int tx, int ty, bool preservePhase = false);

    void paintContents(PaintInfo&, int tx, int ty);

    void paintColumnContents(PaintInfo&, int tx, int ty, bool paintFloats = false);

    void paintColumnRules(PaintInfo&, int tx, int ty);

    void paintChildren(PaintInfo&, int tx, int ty);

    void paintEllipsisBoxes(PaintInfo&, int tx, int ty);

    void paintSelection(PaintInfo&, int tx, int ty);

    void paintCaret(PaintInfo&, int tx, int ty, CaretType);

    void insertFloatingObject(RenderBox*);

    void removeFloatingObject(RenderBox*);

    // Called from lineWidth, to position the floats added in the last line.

    // Returns ture if and only if it has positioned any floats.

    bool positionNewFloats();

    void clearFloats();

    int getClearDelta(RenderBox* child, int yPos);

    virtual bool avoidsFloats() const;

    bool hasOverhangingFloats() { return parent() && !hasColumns() && floatBottom() > height(); }

    void addIntrudingFloats(RenderBlock* prev, int xoffset, int yoffset);

    int addOverhangingFloats(RenderBlock* child, int xoffset, int yoffset, bool makeChildPaintOtherFloats);

    int nextFloatBottomBelow(int) const;

    int floatBottom() const;

    inline int leftBottom();

    inline int rightBottom();

    int rightOffset() const;

    int leftOffset() const;

    virtual bool hitTestColumns(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);

    virtual bool hitTestContents(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);

    virtual bool isPointInOverflowControl(HitTestResult&, int x, int y, int tx, int ty);

    void calcInlinePrefWidths();

    void calcBlockPrefWidths();

    // Obtains the nearest enclosing block (including this block) that contributes a first-line style to our inline

    // children.

    virtual RenderBlock* firstLineBlock() const;

    bool inRootBlockContext() const;

    virtual IntRect rectWithOutlineForRepaint(RenderBoxModelObject* repaintContainer, int outlineWidth);

    virtual RenderStyle* outlineStyleForRepaint() const;

    virtual RenderObject* hoverAncestor() const;

    virtual void updateDragState(bool dragOn);

    virtual void childBecameNonInline(RenderObject* child);

    virtual IntRect selectionRectForRepaint(RenderBoxModelObject* repaintContainer, bool /*clipToVisibleContent*/)

    {

        return selectionGapRectsForRepaint(repaintContainer);

    }

    virtual bool shouldPaintSelectionGaps() const;

    bool isSelectionRoot() const;

    GapRects fillSelectionGaps(RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty,

                               int& lastTop, int& lastLeft, int& lastRight, const PaintInfo* = 0);

    GapRects fillInlineSelectionGaps(RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty,

                                     int& lastTop, int& lastLeft, int& lastRight, const PaintInfo*);

    GapRects fillBlockSelectionGaps(RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty,

                                    int& lastTop, int& lastLeft, int& lastRight, const PaintInfo*);

    IntRect fillVerticalSelectionGap(int lastTop, int lastLeft, int lastRight, int bottomY, RenderBlock* rootBlock,

                                     int blockX, int blockY, const PaintInfo*);

    int leftSelectionOffset(RenderBlock* rootBlock, int y);

    int rightSelectionOffset(RenderBlock* rootBlock, int y);

    virtual void absoluteRects(Vector<IntRect>&, int tx, int ty);

    virtual void absoluteQuads(Vector<FloatQuad>&);

    int desiredColumnWidth() const;

    unsigned desiredColumnCount() const;

    Vector<IntRect>* columnRects() const;

    void setDesiredColumnCountAndWidth(int count, int width);

    int columnGap() const;

    void paintContinuationOutlines(PaintInfo&, int tx, int ty);

    virtual IntRect localCaretRect(InlineBox*, int caretOffset, int* extraWidthToEndOfLine = 0);

    virtual void addFocusRingRects(GraphicsContext*, int tx, int ty);

    void adjustPointToColumnContents(IntPoint&) const;

    void adjustForBorderFit(int x, int& left, int& right) const; // Helper function for borderFitAdjust

    void markLinesDirtyInVerticalRange(int top, int bottom);

    void newLine(EClear);

    Position positionForBox(InlineBox*, bool start = true) const;

    Position positionForRenderer(RenderObject*, bool start = true) const;

    VisiblePosition positionForPointWithInlineChildren(const IntPoint&);

    // Adjust tx and ty from painting offsets to the local coords of this renderer

    void offsetForContents(int& tx, int& ty) const;

    void calcColumnWidth();

    int layoutColumns(int endOfContent = -1);

    bool expandsToEncloseOverhangingFloats() const;

    void updateScrollInfoAfterLayout();

    struct FloatingObject {

        enum Type {

            FloatLeft,

            FloatRight

        };

        FloatingObject(Type type)

            : m_renderer(0)

            , m_top(0)

            , m_bottom(0)

            , m_left(0)

            , m_width(0)

            , m_type(type)

            , m_shouldPaint(true)

            , m_isDescendant(false)

        {

        }

        Type type() { return static_cast<Type>(m_type); }

        RenderBox* m_renderer;

        int m_top;

        int m_bottom;

        int m_left;

        int m_width;

        unsigned m_type : 1; // Type (left or right aligned)

        bool m_shouldPaint : 1;

        bool m_isDescendant : 1;

    };

    class MarginInfo {

        // Collapsing flags for whether we can collapse our margins with our children's margins.

        bool m_canCollapseWithChildren : 1;

        bool m_canCollapseTopWithChildren : 1;

        bool m_canCollapseBottomWithChildren : 1;

        // Whether or not we are a quirky container, i.e., do we collapse away top and bottom

        // margins in our container.  Table cells and the body are the common examples. We

        // also have a custom style property for Safari RSS to deal with TypePad blog articles.

        bool m_quirkContainer : 1;

        // This flag tracks whether we are still looking at child margins that can all collapse together at the beginning of a block.  

        // They may or may not collapse with the top margin of the block (|m_canCollapseTopWithChildren| tells us that), but they will

        // always be collapsing with one another.  This variable can remain set to true through multiple iterations 

        // as long as we keep encountering self-collapsing blocks.

        bool m_atTopOfBlock : 1;

        // This flag is set when we know we're examining bottom margins and we know we're at the bottom of the block.

        bool m_atBottomOfBlock : 1;

        // These variables are used to detect quirky margins that we need to collapse away (in table cells

        // and in the body element).

        bool m_topQuirk : 1;

        bool m_bottomQuirk : 1;

        bool m_determinedTopQuirk : 1;

        // These flags track the previous maximal positive and negative margins.

        int m_posMargin;

        int m_negMargin;

    public:

        MarginInfo(RenderBlock* b, int top, int bottom);

        void setAtTopOfBlock(bool b) { m_atTopOfBlock = b; }

        void setAtBottomOfBlock(bool b) { m_atBottomOfBlock = b; }

        void clearMargin() { m_posMargin = m_negMargin = 0; }

        void setTopQuirk(bool b) { m_topQuirk = b; }

        void setBottomQuirk(bool b) { m_bottomQuirk = b; }

        void setDeterminedTopQuirk(bool b) { m_determinedTopQuirk = b; }

        void setPosMargin(int p) { m_posMargin = p; }

        void setNegMargin(int n) { m_negMargin = n; }

        void setPosMarginIfLarger(int p) { if (p > m_posMargin) m_posMargin = p; }

        void setNegMarginIfLarger(int n) { if (n > m_negMargin) m_negMargin = n; }

        void setMargin(int p, int n) { m_posMargin = p; m_negMargin = n; }

        bool atTopOfBlock() const { return m_atTopOfBlock; }

        bool canCollapseWithTop() const { return m_atTopOfBlock && m_canCollapseTopWithChildren; }

        bool canCollapseWithBottom() const { return m_atBottomOfBlock && m_canCollapseBottomWithChildren; }

        bool canCollapseTopWithChildren() const { return m_canCollapseTopWithChildren; }

        bool canCollapseBottomWithChildren() const { return m_canCollapseBottomWithChildren; }

        bool quirkContainer() const { return m_quirkContainer; }

        bool determinedTopQuirk() const { return m_determinedTopQuirk; }

        bool topQuirk() const { return m_topQuirk; }

        bool bottomQuirk() const { return m_bottomQuirk; }

        int posMargin() const { return m_posMargin; }

        int negMargin() const { return m_negMargin; }

        int margin() const { return m_posMargin - m_negMargin; }

    };

    void layoutBlockChild(RenderBox* child, MarginInfo&, int& previousFloatBottom, int& maxFloatBottom);

    void adjustPositionedBlock(RenderBox* child, const MarginInfo&);

    void adjustFloatingBlock(const MarginInfo&);

    bool handleSpecialChild(RenderBox* child, const MarginInfo&);

    bool handleFloatingChild(RenderBox* child, const MarginInfo&);

    bool handlePositionedChild(RenderBox* child, const MarginInfo&);

    bool handleRunInChild(RenderBox* child);

    int collapseMargins(RenderBox* child, MarginInfo&);

    int clearFloatsIfNeeded(RenderBox* child, MarginInfo&, int oldTopPosMargin, int oldTopNegMargin, int yPos);

    int estimateVerticalPosition(RenderBox* child, const MarginInfo&);

    void determineHorizontalPosition(RenderBox* child);

    void handleBottomOfBlock(int top, int bottom, MarginInfo&);

    void setCollapsedBottomMargin(const MarginInfo&);

    // End helper functions and structs used by layoutBlockChildren.

    typedef ListHashSet<RenderBox*>::const_iterator Iterator;

    DeprecatedPtrList<FloatingObject>* m_floatingObjects;

    ListHashSet<RenderBox*>* m_positionedObjects;

    // An inline can be split with blocks occurring in between the inline content.

    // When this occurs we need a pointer to our next object.  We can basically be

    // split into a sequence of inlines and blocks.  The continuation will either be

    // an anonymous block (that houses other blocks) or it will be an inline flow.

    RenderInline* m_inlineContinuation;

    // Allocated only when some of these fields have non-default values

    struct MaxMargin {

        MaxMargin(const RenderBlock* o) 

            : m_topPos(topPosDefault(o))

            , m_topNeg(topNegDefault(o))

            , m_bottomPos(bottomPosDefault(o))

            , m_bottomNeg(bottomNegDefault(o))

        { 

        }

        static int topPosDefault(const RenderBlock* o) { return o->marginTop() > 0 ? o->marginTop() : 0; }

        static int topNegDefault(const RenderBlock* o) { return o->marginTop() < 0 ? -o->marginTop() : 0; }

        static int bottomPosDefault(const RenderBlock* o) { return o->marginBottom() > 0 ? o->marginBottom() : 0; }

        static int bottomNegDefault(const RenderBlock* o) { return o->marginBottom() < 0 ? -o->marginBottom() : 0; }

        int m_topPos;

        int m_topNeg;

        int m_bottomPos;

        int m_bottomNeg;

     };

    MaxMargin* m_maxMargin;

    RenderObjectChildList m_children;

    RenderLineBoxList m_lineBoxes;   // All of the root line boxes created for this block flow.  For example, <div>Hello<br>world.</div> will have two total lines for the <div>.

    mutable int m_lineHeight;

};

inline RenderBlock* toRenderBlock(RenderObject* object)

{ 

    ASSERT(!object || object->isRenderBlock());

    return static_cast<RenderBlock*>(object);

}

inline const RenderBlock* toRenderBlock(const RenderObject* object)

{ 

    ASSERT(!object || object->isRenderBlock());

    return static_cast<const RenderBlock*>(object);