Source/WebCore/rendering/ExclusionShapeInsideInfo.h

/*
 * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef ExclusionShapeInsideInfo_h
#define ExclusionShapeInsideInfo_h

#if ENABLE(CSS_EXCLUSIONS)

#include "ExclusionShape.h"
#include "FloatRect.h"
#include "InlineIterator.h"
#include "LayoutUnit.h"
#include <wtf/OwnPtr.h>
#include <wtf/PassOwnPtr.h>
#include <wtf/Vector.h>

namespace WebCore {

class RenderBlock;

struct LineSegmentRange {
    InlineIterator start;
    InlineIterator end;
    LineSegmentRange(InlineIterator start, InlineIterator end)
        : start(start)
        , end(end)
    {
    }
};
typedef Vector<LineSegmentRange> SegmentRangeList;

class ExclusionShapeInsideInfo {
    WTF_MAKE_FAST_ALLOCATED;
public:
    ~ExclusionShapeInsideInfo();

    static PassOwnPtr<ExclusionShapeInsideInfo> create(RenderBlock* block) { return adoptPtr(new ExclusionShapeInsideInfo(block)); }
    static ExclusionShapeInsideInfo* exclusionShapeInsideInfoForRenderBlock(const RenderBlock*);
    static ExclusionShapeInsideInfo* ensureExclusionShapeInsideInfoForRenderBlock(RenderBlock*);
    static void removeExclusionShapeInsideInfoForRenderBlock(const RenderBlock*);
    static bool isExclusionShapeInsideInfoEnabledForRenderBlock(const RenderBlock*);

    LayoutUnit shapeLogicalTop() const { return shapeLogicalBoundsY(); }
    LayoutUnit shapeLogicalBottom() const { return shapeLogicalBoundsMaxY(); }
    bool lineOverlapsShapeBounds() const { return m_lineTop < shapeLogicalBottom() && m_lineTop + m_lineHeight >= shapeLogicalTop(); }

    bool hasSegments() const
    {
        return lineOverlapsShapeBounds() && m_segments.size();
    }
    const SegmentList& segments() const
    {
        ASSERT(hasSegments());
        return m_segments;
    }
    SegmentRangeList& segmentRanges() { return m_segmentRanges; }
    const SegmentRangeList& segmentRanges() const { return m_segmentRanges; }
    const LineSegment* currentSegment() const
    {
        if (!hasSegments())
            return 0;
        ASSERT(m_segmentRanges.size() < m_segments.size());
        return &m_segments[m_segmentRanges.size()];
    }
    bool computeSegmentsForLine(LayoutUnit lineTop, LayoutUnit lineHeight);
    bool adjustLogicalLineTop(float minSegmentWidth);
    void computeShapeSize(LayoutUnit logicalWidth, LayoutUnit logicalHeight);
    void dirtyShapeSize() { m_shapeSizeDirty = true; }

    LayoutUnit logicalLineTop() const { return m_lineTop; }

private:
    ExclusionShapeInsideInfo(RenderBlock*);

    inline LayoutUnit shapeLogicalBoundsY() const
    {
        ASSERT(m_shape);
        // Use fromFloatCeil() to ensure that the returned LayoutUnit value is within the shape's bounds.
        return LayoutUnit::fromFloatCeil(m_shape->shapeLogicalBoundingBox().y());
    }

    inline LayoutUnit shapeLogicalBoundsMaxY() const
    {
        ASSERT(m_shape);
        // Use fromFloatFloor() to ensure that the returned LayoutUnit value is within the shape's bounds.
        return LayoutUnit::fromFloatFloor(m_shape->shapeLogicalBoundingBox().maxY());
    }

    RenderBlock* m_block;
    OwnPtr<ExclusionShape> m_shape;

    LayoutUnit m_lineTop;
    LayoutUnit m_lineHeight;
    LayoutUnit m_logicalWidth;
    LayoutUnit m_logicalHeight;

    SegmentList m_segments;
    SegmentRangeList m_segmentRanges;
    bool m_shapeSizeDirty;
};

}
#endif
#endif