| // Copyright 2014 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_SCROLL_OFFSET_H_ |
| #define UI_GFX_GEOMETRY_SCROLL_OFFSET_H_ |
| |
| #include <iosfwd> |
| #include <string> |
| |
| #include "ui/gfx/geometry/geometry_export.h" |
| #include "ui/gfx/geometry/safe_integer_conversions.h" |
| #include "ui/gfx/geometry/vector2d.h" |
| |
| namespace gfx { |
| |
| // TODO(szager): Reconcile terminology with blink. An 'offset' here corresponds |
| // to a 'position' in blink. In blink, 'offset' means something else. See |
| // third_party/WebKit/Source/core/layout/README.md for more information. |
| |
| class GEOMETRY_EXPORT ScrollOffset { |
| public: |
| ScrollOffset() : x_(0), y_(0) {} |
| ScrollOffset(float x, float y) : x_(x), y_(y) {} |
| explicit ScrollOffset(const Vector2dF& v) : x_(v.x()), y_(v.y()) {} |
| explicit ScrollOffset(const Vector2d& v) : x_(v.x()), y_(v.y()) {} |
| |
| float x() const { return x_; } |
| void set_x(float x) { x_ = x; } |
| |
| float y() const { return y_; } |
| void set_y(float y) { y_ = y; } |
| |
| // True if both components are 0. |
| bool IsZero() const { |
| return x_ == 0 && y_ == 0; |
| } |
| |
| // Add the components of the |other| ScrollOffset to the current ScrollOffset. |
| void Add(const ScrollOffset& other) { |
| x_ += other.x_; |
| y_ += other.y_; |
| } |
| |
| // Subtract the components of the |other| ScrollOffset from the current |
| // ScrollOffset. |
| void Subtract(const ScrollOffset& other) { |
| x_ -= other.x_; |
| y_ -= other.y_; |
| } |
| |
| Vector2dF DeltaFrom(const ScrollOffset& v) const { |
| return Vector2dF(x_ - v.x(), y_ - v.y()); |
| } |
| |
| void operator+=(const ScrollOffset& other) { Add(other); } |
| void operator-=(const ScrollOffset& other) { Subtract(other); } |
| |
| void SetToMin(const ScrollOffset& other) { |
| x_ = x_ <= other.x_ ? x_ : other.x_; |
| y_ = y_ <= other.y_ ? y_ : other.y_; |
| } |
| |
| void SetToMax(const ScrollOffset& other) { |
| x_ = x_ >= other.x_ ? x_ : other.x_; |
| y_ = y_ >= other.y_ ? y_ : other.y_; |
| } |
| |
| void Scale(float scale) { Scale(scale, scale); } |
| void Scale(float x_scale, float y_scale) { |
| x_ *= x_scale; |
| y_ *= y_scale; |
| } |
| |
| std::string ToString() const; |
| |
| private: |
| float x_; |
| float y_; |
| }; |
| |
| inline bool operator==(const ScrollOffset& lhs, const ScrollOffset& rhs) { |
| return lhs.x() == rhs.x() && lhs.y() == rhs.y(); |
| } |
| |
| inline bool operator!=(const ScrollOffset& lhs, const ScrollOffset& rhs) { |
| return lhs.x() != rhs.x() || lhs.y() != rhs.y(); |
| } |
| |
| inline ScrollOffset operator-(const ScrollOffset& v) { |
| return ScrollOffset(-v.x(), -v.y()); |
| } |
| |
| inline ScrollOffset operator+(const ScrollOffset& lhs, |
| const ScrollOffset& rhs) { |
| ScrollOffset result = lhs; |
| result.Add(rhs); |
| return result; |
| } |
| |
| inline ScrollOffset operator-(const ScrollOffset& lhs, |
| const ScrollOffset& rhs) { |
| ScrollOffset result = lhs; |
| result.Add(-rhs); |
| return result; |
| } |
| |
| inline Vector2d ScrollOffsetToFlooredVector2d(const ScrollOffset& v) { |
| return Vector2d(ToFlooredInt(v.x()), ToFlooredInt(v.y())); |
| } |
| |
| inline Vector2dF ScrollOffsetToVector2dF(const ScrollOffset& v) { |
| return Vector2dF(v.x(), v.y()); |
| } |
| |
| inline ScrollOffset ScrollOffsetWithDelta(const ScrollOffset& offset, |
| const Vector2dF& delta) { |
| return ScrollOffset(offset.x() + delta.x(), |
| offset.y() + delta.y()); |
| } |
| |
| // 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 ScrollOffset& scroll_offset, ::std::ostream* os); |
| |
| } // namespace gfx |
| |
| #endif // UI_GFX_GEOMETRY_SCROLL_OFFSET_H_ |