flutter_flutter/engine/platform/geometry/LayoutRect.h

/*
 * Copyright (c) 2012, Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 *
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#ifndef LayoutRect_h
#define LayoutRect_h

#include "sky/engine/platform/geometry/IntRect.h"
#include "sky/engine/platform/geometry/LayoutBoxExtent.h"
#include "sky/engine/platform/geometry/LayoutPoint.h"
#include "sky/engine/wtf/Vector.h"

namespace blink {

class FloatRect;

class PLATFORM_EXPORT LayoutRect {
public:
    LayoutRect() { }
    LayoutRect(const LayoutPoint& location, const LayoutSize& size)
        : m_location(location), m_size(size) { }
    LayoutRect(LayoutUnit x, LayoutUnit y, LayoutUnit width, LayoutUnit height)
        : m_location(LayoutPoint(x, y)), m_size(LayoutSize(width, height)) { }
    LayoutRect(const FloatPoint& location, const FloatSize& size)
        : m_location(location), m_size(size) { }
    LayoutRect(const IntRect& rect) : m_location(rect.location()), m_size(rect.size()) { }

    explicit LayoutRect(const FloatRect&); // don't do this implicitly since it's lossy

    LayoutPoint location() const { return m_location; }
    LayoutSize size() const { return m_size; }

    IntPoint pixelSnappedLocation() const { return roundedIntPoint(m_location); }
    IntSize pixelSnappedSize() const { return IntSize(snapSizeToPixel(m_size.width(), m_location.x()), snapSizeToPixel(m_size.height(), m_location.y())); }

    void setLocation(const LayoutPoint& location) { m_location = location; }
    void setSize(const LayoutSize& size) { m_size = size; }

    ALWAYS_INLINE LayoutUnit x() const { return m_location.x(); }
    ALWAYS_INLINE LayoutUnit y() const { return m_location.y(); }
    ALWAYS_INLINE LayoutUnit maxX() const { return x() + width(); }
    ALWAYS_INLINE LayoutUnit maxY() const { return y() + height(); }
    LayoutUnit width() const { return m_size.width(); }
    LayoutUnit height() const { return m_size.height(); }

    int pixelSnappedX() const { return x().round(); }
    int pixelSnappedY() const { return y().round(); }
    int pixelSnappedWidth() const { return snapSizeToPixel(width(), x()); }
    int pixelSnappedHeight() const { return snapSizeToPixel(height(), y()); }
    int pixelSnappedMaxX() const { return (m_location.x() + m_size.width()).round(); }
    int pixelSnappedMaxY() const { return (m_location.y() + m_size.height()).round(); }

    void setX(LayoutUnit x) { m_location.setX(x); }
    void setY(LayoutUnit y) { m_location.setY(y); }
    void setWidth(LayoutUnit width) { m_size.setWidth(width); }
    void setHeight(LayoutUnit height) { m_size.setHeight(height); }

    ALWAYS_INLINE bool isEmpty() const { return m_size.isEmpty(); }

    // NOTE: The result is rounded to integer values, and thus may be not the exact
    // center point.
    LayoutPoint center() const { return LayoutPoint(x() + width() / 2, y() + height() / 2); }

    void move(const LayoutSize& size) { m_location += size; }
    void moveBy(const LayoutPoint& offset) { m_location.move(offset.x(), offset.y()); }
    void move(LayoutUnit dx, LayoutUnit dy) { m_location.move(dx, dy); }

    void expand(const LayoutSize& size) { m_size += size; }
    void expand(const LayoutBoxExtent& box)
    {
        m_location.move(-box.left(), -box.top());
        m_size.expand(box.left() + box.right(), box.top() + box.bottom());
    }
    void expand(LayoutUnit dw, LayoutUnit dh) { m_size.expand(dw, dh); }
    void contract(const LayoutSize& size) { m_size -= size; }
    void contract(const LayoutBoxExtent& box)
    {
        m_location.move(box.left(), box.top());
        m_size.shrink(box.left() + box.right(), box.top() + box.bottom());
    }
    void contract(LayoutUnit dw, LayoutUnit dh) { m_size.expand(-dw, -dh); }

    void shiftXEdgeTo(LayoutUnit edge)
    {
        LayoutUnit delta = edge - x();
        setX(edge);
        setWidth(std::max<LayoutUnit>(0, width() - delta));
    }
    void shiftMaxXEdgeTo(LayoutUnit edge)
    {
        LayoutUnit delta = edge - maxX();
        setWidth(std::max<LayoutUnit>(0, width() + delta));
    }
    void shiftYEdgeTo(LayoutUnit edge)
    {
        LayoutUnit delta = edge - y();
        setY(edge);
        setHeight(std::max<LayoutUnit>(0, height() - delta));
    }
    void shiftMaxYEdgeTo(LayoutUnit edge)
    {
        LayoutUnit delta = edge - maxY();
        setHeight(std::max<LayoutUnit>(0, height() + delta));
    }

    LayoutPoint minXMinYCorner() const { return m_location; } // typically topLeft
    LayoutPoint maxXMinYCorner() const { return LayoutPoint(m_location.x() + m_size.width(), m_location.y()); } // typically topRight
    LayoutPoint minXMaxYCorner() const { return LayoutPoint(m_location.x(), m_location.y() + m_size.height()); } // typically bottomLeft
    LayoutPoint maxXMaxYCorner() const { return LayoutPoint(m_location.x() + m_size.width(), m_location.y() + m_size.height()); } // typically bottomRight

    bool intersects(const LayoutRect&) const;
    bool contains(const LayoutRect&) const;

    // This checks to see if the rect contains x,y in the traditional sense.
    // Equivalent to checking if the rect contains a 1x1 rect below and to the right of (px,py).
    bool contains(LayoutUnit px, LayoutUnit py) const
        { return px >= x() && px < maxX() && py >= y() && py < maxY(); }
    bool contains(const LayoutPoint& point) const { return contains(point.x(), point.y()); }

    void intersect(const LayoutRect&);
    void unite(const LayoutRect&);
    void uniteIfNonZero(const LayoutRect&);

    void inflateX(LayoutUnit dx)
    {
        m_location.setX(m_location.x() - dx);
        m_size.setWidth(m_size.width() + dx + dx);
    }
    void inflateY(LayoutUnit dy)
    {
        m_location.setY(m_location.y() - dy);
        m_size.setHeight(m_size.height() + dy + dy);
    }
    void inflate(LayoutUnit d) { inflateX(d); inflateY(d); }
    void scale(float s);
    void scale(float xAxisScale, float yAxisScale);

    LayoutRect transposedRect() const { return LayoutRect(m_location.transposedPoint(), m_size.transposedSize()); }

    static LayoutRect infiniteRect()
    {
        // Return a rect that is slightly smaller than the true max rect to allow pixelSnapping to round up to the nearest IntRect without overflowing.
        return LayoutRect(LayoutUnit::nearlyMin() / 2, LayoutUnit::nearlyMin() / 2, LayoutUnit::nearlyMax(), LayoutUnit::nearlyMax());
    }

#ifndef NDEBUG
    // Prints the rect to the screen.
    void show(bool showRawValue = false) const;
#endif

private:
    LayoutPoint m_location;
    LayoutSize m_size;
};

inline LayoutRect intersection(const LayoutRect& a, const LayoutRect& b)
{
    LayoutRect c = a;
    c.intersect(b);
    return c;
}

inline LayoutRect unionRect(const LayoutRect& a, const LayoutRect& b)
{
    LayoutRect c = a;
    c.unite(b);
    return c;
}

PLATFORM_EXPORT LayoutRect unionRect(const Vector<LayoutRect>&);

ALWAYS_INLINE bool operator==(const LayoutRect& a, const LayoutRect& b)
{
    return a.location() == b.location() && a.size() == b.size();
}

inline bool operator!=(const LayoutRect& a, const LayoutRect& b)
{
    return a.location() != b.location() || a.size() != b.size();
}

inline IntRect pixelSnappedIntRect(const LayoutRect& rect)
{
    return IntRect(roundedIntPoint(rect.location()), IntSize(
        snapSizeToPixel(rect.width(), rect.x()),
        snapSizeToPixel(rect.height(), rect.y())));
}

PLATFORM_EXPORT IntRect enclosingIntRect(const LayoutRect&);
PLATFORM_EXPORT LayoutRect enclosingLayoutRect(const FloatRect&);

inline IntRect pixelSnappedIntRect(LayoutUnit left, LayoutUnit top, LayoutUnit width, LayoutUnit height)
{
    return IntRect(left.round(), top.round(), snapSizeToPixel(width, left), snapSizeToPixel(height, top));
}

inline IntRect pixelSnappedIntRectFromEdges(LayoutUnit left, LayoutUnit top, LayoutUnit right, LayoutUnit bottom)
{
    return IntRect(left.round(), top.round(), snapSizeToPixel(right - left, left), snapSizeToPixel(bottom - top, top));
}

inline IntRect pixelSnappedIntRect(LayoutPoint location, LayoutSize size)
{
    return IntRect(roundedIntPoint(location), pixelSnappedIntSize(size, location));
}

} // namespace blink

#endif // LayoutRect_h