1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // A template for a simple rectangle class. The containment semantics 6 // are array-like; that is, the coordinate (x, y) is considered to be 7 // contained by the rectangle, but the coordinate (x + width, y) is not. 8 // The class will happily let you create malformed rectangles (that is, 9 // rectangles with negative width and/or height), but there will be assertions 10 // in the operations (such as Contains()) to complain in this case. 11 12 #ifndef UI_GFX_RECT_BASE_H_ 13 #define UI_GFX_RECT_BASE_H_ 14 15 #include <string> 16 17 #include "base/compiler_specific.h" 18 19 namespace gfx { 20 21 template<typename Class, 22 typename PointClass, 23 typename SizeClass, 24 typename InsetsClass, 25 typename VectorClass, 26 typename Type> 27 class UI_EXPORT RectBase { 28 public: 29 Type x() const { return origin_.x(); } 30 void set_x(Type x) { origin_.set_x(x); } 31 32 Type y() const { return origin_.y(); } 33 void set_y(Type y) { origin_.set_y(y); } 34 35 Type width() const { return size_.width(); } 36 void set_width(Type width) { size_.set_width(width); } 37 38 Type height() const { return size_.height(); } 39 void set_height(Type height) { size_.set_height(height); } 40 41 const PointClass& origin() const { return origin_; } 42 void set_origin(const PointClass& origin) { origin_ = origin; } 43 44 const SizeClass& size() const { return size_; } 45 void set_size(const SizeClass& size) { size_ = size; } 46 47 Type right() const { return x() + width(); } 48 Type bottom() const { return y() + height(); } 49 50 PointClass top_right() const { return PointClass(right(), y()); } 51 PointClass bottom_left() const { return PointClass(x(), bottom()); } 52 PointClass bottom_right() const { return PointClass(right(), bottom()); } 53 54 VectorClass OffsetFromOrigin() const { 55 return VectorClass(x(), y()); 56 } 57 58 void SetRect(Type x, Type y, Type width, Type height); 59 60 // Shrink the rectangle by a horizontal and vertical distance on all sides. 61 void Inset(Type horizontal, Type vertical) { 62 Inset(horizontal, vertical, horizontal, vertical); 63 } 64 65 // Shrink the rectangle by the given insets. 66 void Inset(const InsetsClass& insets); 67 68 // Shrink the rectangle by the specified amount on each side. 69 void Inset(Type left, Type top, Type right, Type bottom); 70 71 // Move the rectangle by a horizontal and vertical distance. 72 void Offset(Type horizontal, Type vertical); 73 void Offset(const VectorClass& distance) { 74 Offset(distance.x(), distance.y()); 75 } 76 void operator+=(const VectorClass& offset); 77 void operator-=(const VectorClass& offset); 78 79 InsetsClass InsetsFrom(const Class& inner) const { 80 return InsetsClass(inner.y() - y(), 81 inner.x() - x(), 82 bottom() - inner.bottom(), 83 right() - inner.right()); 84 } 85 86 // Returns true if the area of the rectangle is zero. 87 bool IsEmpty() const { return size_.IsEmpty(); } 88 89 // A rect is less than another rect if its origin is less than 90 // the other rect's origin. If the origins are equal, then the 91 // shortest rect is less than the other. If the origin and the 92 // height are equal, then the narrowest rect is less than. 93 // This comparison is required to use Rects in sets, or sorted 94 // vectors. 95 bool operator<(const Class& other) const; 96 97 // Returns true if the point identified by point_x and point_y falls inside 98 // this rectangle. The point (x, y) is inside the rectangle, but the 99 // point (x + width, y + height) is not. 100 bool Contains(Type point_x, Type point_y) const; 101 102 // Returns true if the specified point is contained by this rectangle. 103 bool Contains(const PointClass& point) const { 104 return Contains(point.x(), point.y()); 105 } 106 107 // Returns true if this rectangle contains the specified rectangle. 108 bool Contains(const Class& rect) const; 109 110 // Returns true if this rectangle intersects the specified rectangle. 111 // An empty rectangle doesn't intersect any rectangle. 112 bool Intersects(const Class& rect) const; 113 114 // Computes the intersection of this rectangle with the given rectangle. 115 void Intersect(const Class& rect); 116 117 // Computes the union of this rectangle with the given rectangle. The union 118 // is the smallest rectangle containing both rectangles. 119 void Union(const Class& rect); 120 121 // Computes the rectangle resulting from subtracting |rect| from |*this|, 122 // i.e. the bounding rect of |Region(*this) - Region(rect)|. 123 void Subtract(const Class& rect); 124 125 // Fits as much of the receiving rectangle into the supplied rectangle as 126 // possible, becoming the result. For example, if the receiver had 127 // a x-location of 2 and a width of 4, and the supplied rectangle had 128 // an x-location of 0 with a width of 5, the returned rectangle would have 129 // an x-location of 1 with a width of 4. 130 void AdjustToFit(const Class& rect); 131 132 // Returns the center of this rectangle. 133 PointClass CenterPoint() const; 134 135 // Becomes a rectangle that has the same center point but with a size capped 136 // at given |size|. 137 void ClampToCenteredSize(const SizeClass& size); 138 139 // Splits |this| in two halves, |left_half| and |right_half|. 140 void SplitVertically(Class* left_half, Class* right_half) const; 141 142 // Returns true if this rectangle shares an entire edge (i.e., same width or 143 // same height) with the given rectangle, and the rectangles do not overlap. 144 bool SharesEdgeWith(const Class& rect) const; 145 146 protected: 147 RectBase(const PointClass& origin, const SizeClass& size) 148 : origin_(origin), size_(size) {} 149 explicit RectBase(const SizeClass& size) 150 : size_(size) {} 151 explicit RectBase(const PointClass& origin) 152 : origin_(origin) {} 153 // Destructor is intentionally made non virtual and protected. 154 // Do not make this public. 155 ~RectBase() {} 156 157 private: 158 PointClass origin_; 159 SizeClass size_; 160 }; 161 162 } // namespace gfx 163 164 #endif // UI_GFX_RECT_BASE_H_ 165