| // 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. |
| |
| #ifndef UI_GFX_GEOMETRY_INSETS_H_ |
| #define UI_GFX_GEOMETRY_INSETS_H_ |
| |
| #include <memory> |
| #include <string> |
| |
| #include "gfx/gfx_export.h" |
| #include "insets_f.h" |
| #include "size.h" |
| |
| namespace gfx { |
| |
| class Vector2d; |
| |
| // Represents the widths of the four borders or margins of an unspecified |
| // rectangle. An Insets stores the thickness of the top, left, bottom and right |
| // edges, without storing the actual size and position of the rectangle itself. |
| // |
| // This can be used to represent a space within a rectangle, by "shrinking" the |
| // rectangle by the inset amount on all four sides. Alternatively, it can |
| // represent a border that has a different thickness on each side. |
| class GFX_EXPORT Insets { |
| public: |
| constexpr Insets() : top_(0), left_(0), bottom_(0), right_(0) {} |
| constexpr explicit Insets(int all) |
| : top_(all), |
| left_(all), |
| bottom_(GetClampedValue(all, all)), |
| right_(GetClampedValue(all, all)) {} |
| constexpr explicit Insets(int vertical, int horizontal) |
| : top_(vertical), |
| left_(horizontal), |
| bottom_(GetClampedValue(vertical, vertical)), |
| right_(GetClampedValue(horizontal, horizontal)) {} |
| constexpr Insets(int top, int left, int bottom, int right) |
| : top_(top), |
| left_(left), |
| bottom_(GetClampedValue(top, bottom)), |
| right_(GetClampedValue(left, right)) {} |
| |
| constexpr int top() const { return top_; } |
| constexpr int left() const { return left_; } |
| constexpr int bottom() const { return bottom_; } |
| constexpr int right() const { return right_; } |
| |
| // Returns the total width taken up by the insets, which is the sum of the |
| // left and right insets. |
| constexpr int width() const { return left_ + right_; } |
| |
| // Returns the total height taken up by the insets, which is the sum of the |
| // top and bottom insets. |
| constexpr int height() const { return top_ + bottom_; } |
| |
| // Returns the sum of the left and right insets as the width, the sum of the |
| // top and bottom insets as the height. |
| constexpr Size size() const { return Size(width(), height()); } |
| |
| // Returns true if the insets are empty. |
| bool IsEmpty() const { return width() == 0 && height() == 0; } |
| |
| void set_top(int top) { |
| top_ = top; |
| bottom_ = GetClampedValue(top_, bottom_); |
| } |
| void set_left(int left) { |
| left_ = left; |
| right_ = GetClampedValue(left_, right_); |
| } |
| void set_bottom(int bottom) { bottom_ = GetClampedValue(top_, bottom); } |
| void set_right(int right) { right_ = GetClampedValue(left_, right); } |
| |
| void Set(int top, int left, int bottom, int right) { |
| top_ = top; |
| left_ = left; |
| bottom_ = GetClampedValue(top_, bottom); |
| right_ = GetClampedValue(left_, right); |
| } |
| |
| bool operator==(const Insets& insets) const { |
| return top_ == insets.top_ && left_ == insets.left_ && |
| bottom_ == insets.bottom_ && right_ == insets.right_; |
| } |
| |
| bool operator!=(const Insets& insets) const { return !(*this == insets); } |
| |
| void operator+=(const Insets& insets) { |
| top_ = base::ClampAdd(top_, insets.top_); |
| left_ = base::ClampAdd(left_, insets.left_); |
| bottom_ = GetClampedValue(top_, base::ClampAdd(bottom_, insets.bottom_)); |
| right_ = GetClampedValue(left_, base::ClampAdd(right_, insets.right_)); |
| } |
| |
| void operator-=(const Insets& insets) { |
| top_ = base::ClampSub(top_, insets.top_); |
| left_ = base::ClampSub(left_, insets.left_); |
| bottom_ = GetClampedValue(top_, base::ClampSub(bottom_, insets.bottom_)); |
| right_ = GetClampedValue(left_, base::ClampSub(right_, insets.right_)); |
| } |
| |
| Insets operator-() const { |
| return Insets(-base::MakeClampedNum(top_), -base::MakeClampedNum(left_), |
| -base::MakeClampedNum(bottom_), |
| -base::MakeClampedNum(right_)); |
| } |
| |
| Insets Scale(float scale) const { return Scale(scale, scale); } |
| |
| Insets Scale(float x_scale, float y_scale) const { |
| return Insets(static_cast<int>(base::ClampMul(top(), y_scale)), |
| static_cast<int>(base::ClampMul(left(), x_scale)), |
| static_cast<int>(base::ClampMul(bottom(), y_scale)), |
| static_cast<int>(base::ClampMul(right(), x_scale))); |
| } |
| |
| // Adjusts the vertical and horizontal dimensions by the values described in |
| // |vector|. Offsetting insets before applying to a rectangle would be |
| // equivalent to offseting the rectangle then applying the insets. |
| Insets Offset(const gfx::Vector2d& vector) const; |
| |
| operator InsetsF() const { |
| return InsetsF(static_cast<float>(top()), static_cast<float>(left()), |
| static_cast<float>(bottom()), static_cast<float>(right())); |
| } |
| |
| // Returns a string representation of the insets. |
| std::string ToString() const; |
| |
| private: |
| int top_; |
| int left_; |
| int bottom_; |
| int right_; |
| |
| // See rect.h |
| // 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); |
| } |
| |
| // Returns true iff a+b would underflow min int. |
| static constexpr bool AddWouldUnderflow(int a, int b) { |
| return a < 0 && b < 0 && std::numeric_limits<int>::min() - a > b; |
| } |
| |
| // Clamp the right/bottom to avoid integer over/underflow in width() and |
| // height(). This returns the right/bottom given a top_or_left and a |
| // bottom_or_right. |
| // TODO(enne): this should probably use base::ClampAdd, but that |
| // function is not a constexpr. |
| static constexpr int GetClampedValue(int top_or_left, int bottom_or_right) { |
| if (AddWouldOverflow(top_or_left, bottom_or_right)) { |
| return std::numeric_limits<int>::max() - top_or_left; |
| } else if (AddWouldUnderflow(top_or_left, bottom_or_right)) { |
| // If |top_or_left| and |bottom_or_right| are both negative, |
| // adds |top_or_left| to prevent underflow by subtracting it. |
| return std::numeric_limits<int>::min() - top_or_left; |
| } else { |
| return bottom_or_right; |
| } |
| } |
| }; |
| |
| inline Insets operator+(Insets lhs, const Insets& rhs) { |
| lhs += rhs; |
| return lhs; |
| } |
| |
| inline Insets operator-(Insets lhs, const Insets& rhs) { |
| lhs -= rhs; |
| return lhs; |
| } |
| |
| } // namespace gfx |
| |
| #endif // UI_GFX_GEOMETRY_INSETS_H_ |