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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Defines a simple integer rectangle class. The containment semantics
// are array-like; that is, the coordinate (x, y) is considered to be
// contained by the rectangle, but the coordinate (x + width, y) is not.
// The class will happily let you create malformed rectangles (that is,
// rectangles with negative width and/or height), but there will be assertions
// in the operations (such as Contains()) to complain in this case.
#ifndef UI_GFX_GEOMETRY_RECT_H_
#define UI_GFX_GEOMETRY_RECT_H_
#include <cmath>
#include <iosfwd>
#include <string>
#include "base/logging.h"
#include "build/build_config.h"
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/geometry/safe_integer_conversions.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/geometry/vector2d.h"
#if defined(OS_WIN)
typedef struct tagRECT RECT;
#elif defined(OS_MACOSX)
typedef struct CGRect CGRect;
#endif
namespace gfx {
class Insets;
class GFX_EXPORT Rect {
public:
constexpr Rect() = default;
constexpr Rect(int width, int height) : size_(width, height) {}
constexpr Rect(int x, int y, int width, int height)
: origin_(x, y),
size_(GetClampedValue(x, width), GetClampedValue(y, height)) {}
constexpr explicit Rect(const Size& size) : size_(size) {}
constexpr Rect(const Point& origin, const Size& size)
: origin_(origin),
size_(GetClampedValue(origin.x(), size.width()),
GetClampedValue(origin.y(), size.height())) {}
#if defined(OS_WIN)
explicit Rect(const RECT& r);
#elif defined(OS_MACOSX)
explicit Rect(const CGRect& r);
#endif
#if defined(OS_WIN)
// Construct an equivalent Win32 RECT object.
RECT ToRECT() const;
#elif defined(OS_MACOSX)
// Construct an equivalent CoreGraphics object.
CGRect ToCGRect() const;
#endif
constexpr int x() const { return origin_.x(); }
// Sets the X position while preserving the width.
void set_x(int x) {
origin_.set_x(x);
size_.set_width(GetClampedValue(x, width()));
}
constexpr int y() const { return origin_.y(); }
// Sets the Y position while preserving the height.
void set_y(int y) {
origin_.set_y(y);
size_.set_height(GetClampedValue(y, height()));
}
constexpr int width() const { return size_.width(); }
void set_width(int width) { size_.set_width(GetClampedValue(x(), width)); }
constexpr int height() const { return size_.height(); }
void set_height(int height) {
size_.set_height(GetClampedValue(y(), height));
}
constexpr const Point& origin() const { return origin_; }
void set_origin(const Point& origin) {
origin_ = origin;
// Ensure that width and height remain valid.
set_width(width());
set_height(height());
}
constexpr const Size& size() const { return size_; }
void set_size(const Size& size) {
set_width(size.width());
set_height(size.height());
}
constexpr int right() const { return x() + width(); }
constexpr int bottom() const { return y() + height(); }
constexpr Point top_right() const { return Point(right(), y()); }
constexpr Point bottom_left() const { return Point(x(), bottom()); }
constexpr Point bottom_right() const { return Point(right(), bottom()); }
Vector2d OffsetFromOrigin() const { return Vector2d(x(), y()); }
void SetRect(int x, int y, int width, int height) {
origin_.SetPoint(x, y);
// Ensure that width and height remain valid.
set_width(width);
set_height(height);
}
// Use in place of SetRect() when you know the edges of the rectangle instead
// of the dimensions, rather than trying to determine the width/height
// yourself. This safely handles cases where the width/height would overflow.
void SetByBounds(int left, int top, int right, int bottom);
// Shrink the rectangle by a horizontal and vertical distance on all sides.
void Inset(int horizontal, int vertical) {
Inset(horizontal, vertical, horizontal, vertical);
}
// Shrink the rectangle by the given insets.
void Inset(const Insets& insets);
// Shrink the rectangle by the specified amount on each side.
void Inset(int left, int top, int right, int bottom);
// Move the rectangle by a horizontal and vertical distance.
void Offset(int horizontal, int vertical);
void Offset(const Vector2d& distance) { Offset(distance.x(), distance.y()); }
void operator+=(const Vector2d& offset);
void operator-=(const Vector2d& offset);
Insets InsetsFrom(const Rect& inner) const;
// Returns true if the area of the rectangle is zero.
bool IsEmpty() const { return size_.IsEmpty(); }
// A rect is less than another rect if its origin is less than
// the other rect's origin. If the origins are equal, then the
// shortest rect is less than the other. If the origin and the
// height are equal, then the narrowest rect is less than.
// This comparison is required to use Rects in sets, or sorted
// vectors.
bool operator<(const Rect& other) const;
// Returns true if the point identified by point_x and point_y falls inside
// this rectangle. The point (x, y) is inside the rectangle, but the
// point (x + width, y + height) is not.
bool Contains(int point_x, int point_y) const;
// Returns true if the specified point is contained by this rectangle.
bool Contains(const Point& point) const {
return Contains(point.x(), point.y());
}
// Returns true if this rectangle contains the specified rectangle.
bool Contains(const Rect& rect) const;
// Returns true if this rectangle intersects the specified rectangle.
// An empty rectangle doesn't intersect any rectangle.
bool Intersects(const Rect& rect) const;
// Computes the intersection of this rectangle with the given rectangle.
void Intersect(const Rect& rect);
// Computes the union of this rectangle with the given rectangle. The union
// is the smallest rectangle containing both rectangles.
void Union(const Rect& rect);
// Computes the rectangle resulting from subtracting |rect| from |*this|,
// i.e. the bounding rect of |Region(*this) - Region(rect)|.
void Subtract(const Rect& rect);
// Fits as much of the receiving rectangle into the supplied rectangle as
// possible, becoming the result. For example, if the receiver had
// a x-location of 2 and a width of 4, and the supplied rectangle had
// an x-location of 0 with a width of 5, the returned rectangle would have
// an x-location of 1 with a width of 4.
void AdjustToFit(const Rect& rect);
// Returns the center of this rectangle.
Point CenterPoint() const;
// Becomes a rectangle that has the same center point but with a size capped
// at given |size|.
void ClampToCenteredSize(const Size& size);
// Splits |this| in two halves, |left_half| and |right_half|.
void SplitVertically(Rect* left_half, Rect* right_half) const;
// Returns true if this rectangle shares an entire edge (i.e., same width or
// same height) with the given rectangle, and the rectangles do not overlap.
bool SharesEdgeWith(const Rect& rect) const;
// Returns the manhattan distance from the rect to the point. If the point is
// inside the rect, returns 0.
int ManhattanDistanceToPoint(const Point& point) const;
// Returns the manhattan distance between the contents of this rect and the
// contents of the given rect. That is, if the intersection of the two rects
// is non-empty then the function returns 0. If the rects share a side, it
// returns the smallest non-zero value appropriate for int.
int ManhattanInternalDistance(const Rect& rect) const;
std::string ToString() const;
bool ApproximatelyEqual(const Rect& rect, int tolerance) const;
private:
gfx::Point origin_;
gfx::Size size_;
// Returns true iff a+b would overflow max int.
static constexpr bool AddWouldOverflow(int a, int b) {
// In this function, GCC tries to make optimizations that would only work if
// max - a wouldn't overflow but it isn't smart enough to notice that a > 0.
// So cast everything to unsigned to avoid this. As it is guaranteed that
// max - a and b are both already positive, the cast is a noop.
//
// This is intended to be: a > 0 && max - a < b
return a > 0 && b > 0 &&
static_cast<unsigned>(std::numeric_limits<int>::max() - a) <
static_cast<unsigned>(b);
}
// Clamp the size to avoid integer overflow in bottom() and right().
// This returns the width given an origin and a width.
// TODO(enne): this should probably use base::ClampAdd, but that
// function is not a constexpr.
static constexpr int GetClampedValue(int origin, int size) {
return AddWouldOverflow(origin, size)
? std::numeric_limits<int>::max() - origin
: size;
}
};
inline bool operator==(const Rect& lhs, const Rect& rhs) {
return lhs.origin() == rhs.origin() && lhs.size() == rhs.size();
}
inline bool operator!=(const Rect& lhs, const Rect& rhs) {
return !(lhs == rhs);
}
GFX_EXPORT Rect operator+(const Rect& lhs, const Vector2d& rhs);
GFX_EXPORT Rect operator-(const Rect& lhs, const Vector2d& rhs);
inline Rect operator+(const Vector2d& lhs, const Rect& rhs) {
return rhs + lhs;
}
GFX_EXPORT Rect IntersectRects(const Rect& a, const Rect& b);
GFX_EXPORT Rect UnionRects(const Rect& a, const Rect& b);
GFX_EXPORT Rect SubtractRects(const Rect& a, const Rect& b);
// Constructs a rectangle with |p1| and |p2| as opposite corners.
//
// This could also be thought of as "the smallest rect that contains both
// points", except that we consider points on the right/bottom edges of the
// rect to be outside the rect. So technically one or both points will not be
// contained within the rect, because they will appear on one of these edges.
GFX_EXPORT Rect BoundingRect(const Point& p1, const Point& p2);
// Scales the rect and returns the enclosing rect. Use this only the inputs are
// known to not overflow. Use ScaleToEnclosingRectSafe if the inputs are
// unknown and need to use saturated math.
inline Rect ScaleToEnclosingRect(const Rect& rect,
float x_scale,
float y_scale) {
if (x_scale == 1.f && y_scale == 1.f)
return rect;
// These next functions cast instead of using e.g. ToFlooredInt() because we
// haven't checked to ensure that the clamping behavior of the helper
// functions doesn't degrade performance, and callers shouldn't be passing
// values that cause overflow anyway.
DCHECK(base::IsValueInRangeForNumericType<int>(
std::floor(rect.x() * x_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::floor(rect.y() * y_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::ceil(rect.right() * x_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::ceil(rect.bottom() * y_scale)));
int x = static_cast<int>(std::floor(rect.x() * x_scale));
int y = static_cast<int>(std::floor(rect.y() * y_scale));
int r = rect.width() == 0 ?
x : static_cast<int>(std::ceil(rect.right() * x_scale));
int b = rect.height() == 0 ?
y : static_cast<int>(std::ceil(rect.bottom() * y_scale));
return Rect(x, y, r - x, b - y);
}
inline Rect ScaleToEnclosingRect(const Rect& rect, float scale) {
return ScaleToEnclosingRect(rect, scale, scale);
}
// ScaleToEnclosingRect but clamping instead of asserting if the resulting rect
// would overflow.
inline Rect ScaleToEnclosingRectSafe(const Rect& rect,
float x_scale,
float y_scale) {
if (x_scale == 1.f && y_scale == 1.f)
return rect;
int x = base::saturated_cast<int>(std::floor(rect.x() * x_scale));
int y = base::saturated_cast<int>(std::floor(rect.y() * y_scale));
int w = base::saturated_cast<int>(std::ceil(rect.width() * x_scale));
int h = base::saturated_cast<int>(std::ceil(rect.height() * y_scale));
return Rect(x, y, w, h);
}
inline Rect ScaleToEnclosingRectSafe(const Rect& rect, float scale) {
return ScaleToEnclosingRectSafe(rect, scale, scale);
}
inline Rect ScaleToEnclosedRect(const Rect& rect,
float x_scale,
float y_scale) {
if (x_scale == 1.f && y_scale == 1.f)
return rect;
DCHECK(base::IsValueInRangeForNumericType<int>(
std::ceil(rect.x() * x_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::ceil(rect.y() * y_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::floor(rect.right() * x_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::floor(rect.bottom() * y_scale)));
int x = static_cast<int>(std::ceil(rect.x() * x_scale));
int y = static_cast<int>(std::ceil(rect.y() * y_scale));
int r = rect.width() == 0 ?
x : static_cast<int>(std::floor(rect.right() * x_scale));
int b = rect.height() == 0 ?
y : static_cast<int>(std::floor(rect.bottom() * y_scale));
return Rect(x, y, r - x, b - y);
}
inline Rect ScaleToEnclosedRect(const Rect& rect, float scale) {
return ScaleToEnclosedRect(rect, scale, scale);
}
// Scales |rect| by scaling its four corner points. If the corner points lie on
// non-integral coordinate after scaling, their values are rounded to the
// nearest integer.
// This is helpful during layout when relative positions of multiple gfx::Rect
// in a given coordinate space needs to be same after scaling as it was before
// scaling. ie. this gives a lossless relative positioning of rects.
inline Rect ScaleToRoundedRect(const Rect& rect, float x_scale, float y_scale) {
if (x_scale == 1.f && y_scale == 1.f)
return rect;
DCHECK(
base::IsValueInRangeForNumericType<int>(std::round(rect.x() * x_scale)));
DCHECK(
base::IsValueInRangeForNumericType<int>(std::round(rect.y() * y_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::round(rect.right() * x_scale)));
DCHECK(base::IsValueInRangeForNumericType<int>(
std::round(rect.bottom() * y_scale)));
int x = static_cast<int>(std::round(rect.x() * x_scale));
int y = static_cast<int>(std::round(rect.y() * y_scale));
int r = rect.width() == 0
? x
: static_cast<int>(std::round(rect.right() * x_scale));
int b = rect.height() == 0
? y
: static_cast<int>(std::round(rect.bottom() * y_scale));
return Rect(x, y, r - x, b - y);
}
inline Rect ScaleToRoundedRect(const Rect& rect, float scale) {
return ScaleToRoundedRect(rect, scale, scale);
}
// This is declared here for use in gtest-based unit tests but is defined in
// the //ui/gfx:test_support target. Depend on that to use this in your unit
// test. This should not be used in production code - call ToString() instead.
void PrintTo(const Rect& rect, ::std::ostream* os);
} // namespace gfx
#endif // UI_GFX_GEOMETRY_RECT_H_