michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef MOZILLA_GFX_BASESIZE_H_
michael@0: #define MOZILLA_GFX_BASESIZE_H_
michael@0: 
michael@0: #include "mozilla/Attributes.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace gfx {
michael@0: 
michael@0: /**
michael@0:  * Do not use this class directly. Subclass it, pass that subclass as the
michael@0:  * Sub parameter, and only use that subclass. This allows methods to safely
michael@0:  * cast 'this' to 'Sub*'.
michael@0:  */
michael@0: template <class T, class Sub>
michael@0: struct BaseSize {
michael@0:   T width, height;
michael@0: 
michael@0:   // Constructors
michael@0:   MOZ_CONSTEXPR BaseSize() : width(0), height(0) {}
michael@0:   MOZ_CONSTEXPR BaseSize(T aWidth, T aHeight) : width(aWidth), height(aHeight) {}
michael@0: 
michael@0:   void SizeTo(T aWidth, T aHeight) { width = aWidth; height = aHeight; }
michael@0: 
michael@0:   bool IsEmpty() const {
michael@0:     return width == 0 || height == 0;
michael@0:   }
michael@0: 
michael@0:   // Note that '=' isn't defined so we'll get the
michael@0:   // compiler generated default assignment operator
michael@0: 
michael@0:   bool operator==(const Sub& aSize) const {
michael@0:     return width == aSize.width && height == aSize.height;
michael@0:   }
michael@0:   bool operator!=(const Sub& aSize) const {
michael@0:     return width != aSize.width || height != aSize.height;
michael@0:   }
michael@0:   bool operator<=(const Sub& aSize) const {
michael@0:     return width <= aSize.width && height <= aSize.height;
michael@0:   }
michael@0:   bool operator<(const Sub& aSize) const {
michael@0:     return *this <= aSize && *this != aSize;
michael@0:   }
michael@0: 
michael@0:   Sub operator+(const Sub& aSize) const {
michael@0:     return Sub(width + aSize.width, height + aSize.height);
michael@0:   }
michael@0:   Sub operator-(const Sub& aSize) const {
michael@0:     return Sub(width - aSize.width, height - aSize.height);
michael@0:   }
michael@0:   Sub& operator+=(const Sub& aSize) {
michael@0:     width += aSize.width;
michael@0:     height += aSize.height;
michael@0:     return *static_cast<Sub*>(this);
michael@0:   }
michael@0:   Sub& operator-=(const Sub& aSize) {
michael@0:     width -= aSize.width;
michael@0:     height -= aSize.height;
michael@0:     return *static_cast<Sub*>(this);
michael@0:   }
michael@0: 
michael@0:   Sub operator*(T aScale) const {
michael@0:     return Sub(width * aScale, height * aScale);
michael@0:   }
michael@0:   Sub operator/(T aScale) const {
michael@0:     return Sub(width / aScale, height / aScale);
michael@0:   }
michael@0:   void Scale(T aXScale, T aYScale) {
michael@0:     width *= aXScale;
michael@0:     height *= aYScale;
michael@0:   }
michael@0: 
michael@0:   Sub operator*(const Sub& aSize) const {
michael@0:     return Sub(width * aSize.width, height * aSize.height);
michael@0:   }
michael@0:   Sub operator/(const Sub& aSize) const {
michael@0:     return Sub(width / aSize.width, height / aSize.height);
michael@0:   }
michael@0: };
michael@0: 
michael@0: }
michael@0: }
michael@0: 
michael@0: #endif /* MOZILLA_GFX_BASESIZE_H_ */