diff options
Diffstat (limited to 'gfx/2d/BaseMargin.h')
-rw-r--r-- | gfx/2d/BaseMargin.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/gfx/2d/BaseMargin.h b/gfx/2d/BaseMargin.h new file mode 100644 index 0000000000..469541e617 --- /dev/null +++ b/gfx/2d/BaseMargin.h @@ -0,0 +1,164 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef MOZILLA_GFX_BASEMARGIN_H_ +#define MOZILLA_GFX_BASEMARGIN_H_ + +#include <ostream> + +#include "Types.h" + +namespace mozilla { + +/** + * Sides represents a set of physical sides. + */ +struct Sides final { + Sides() : mBits(SideBits::eNone) {} + explicit Sides(SideBits aSideBits) { + MOZ_ASSERT((aSideBits & ~SideBits::eAll) == SideBits::eNone, + "illegal side bits"); + mBits = aSideBits; + } + bool IsEmpty() const { return mBits == SideBits::eNone; } + bool Top() const { return (mBits & SideBits::eTop) == SideBits::eTop; } + bool Right() const { return (mBits & SideBits::eRight) == SideBits::eRight; } + bool Bottom() const { + return (mBits & SideBits::eBottom) == SideBits::eBottom; + } + bool Left() const { return (mBits & SideBits::eLeft) == SideBits::eLeft; } + bool Contains(SideBits aSideBits) const { + MOZ_ASSERT(!(aSideBits & ~SideBits::eAll), "illegal side bits"); + return (mBits & aSideBits) == aSideBits; + } + Sides operator|(Sides aOther) const { + return Sides(SideBits(mBits | aOther.mBits)); + } + Sides operator|(SideBits aSideBits) const { return *this | Sides(aSideBits); } + Sides& operator|=(Sides aOther) { + mBits |= aOther.mBits; + return *this; + } + Sides& operator|=(SideBits aSideBits) { return *this |= Sides(aSideBits); } + bool operator==(Sides aOther) const { return mBits == aOther.mBits; } + bool operator!=(Sides aOther) const { return !(*this == aOther); } + + private: + SideBits mBits; +}; + +namespace gfx { + +/** + * Do not use this class directly. Subclass it, pass that subclass as the + * Sub parameter, and only use that subclass. + */ +template <class T, class Sub, class Coord = T> +struct BaseMargin { + typedef mozilla::Side SideT; // because we have a method named Side + + // Do not change the layout of these members; the Side() methods below + // depend on this order. + Coord top, right, bottom, left; + + // Constructors + BaseMargin() : top(0), right(0), bottom(0), left(0) {} + BaseMargin(Coord aTop, Coord aRight, Coord aBottom, Coord aLeft) + : top(aTop), right(aRight), bottom(aBottom), left(aLeft) {} + + void SizeTo(Coord aTop, Coord aRight, Coord aBottom, Coord aLeft) { + top = aTop; + right = aRight; + bottom = aBottom; + left = aLeft; + } + + Coord LeftRight() const { return left + right; } + Coord TopBottom() const { return top + bottom; } + + Coord& Side(SideT aSide) { + // This is ugly! + return *(&top + int(aSide)); + } + Coord Side(SideT aSide) const { + // This is ugly! + return *(&top + int(aSide)); + } + + Sub& ApplySkipSides(Sides aSkipSides) { + if (aSkipSides.Top()) { + top = 0; + } + if (aSkipSides.Right()) { + right = 0; + } + if (aSkipSides.Bottom()) { + bottom = 0; + } + if (aSkipSides.Left()) { + left = 0; + } + return *static_cast<Sub*>(this); + } + + // Ensures that all our sides are at least as big as the argument. + void EnsureAtLeast(const BaseMargin& aMargin) { + top = std::max(top, aMargin.top); + right = std::max(right, aMargin.right); + bottom = std::max(bottom, aMargin.bottom); + left = std::max(left, aMargin.left); + } + + // Ensures that all our sides are at most as big as the argument. + void EnsureAtMost(const BaseMargin& aMargin) { + top = std::min(top, aMargin.top); + right = std::min(right, aMargin.right); + bottom = std::min(bottom, aMargin.bottom); + left = std::min(left, aMargin.left); + } + + // Overloaded operators. Note that '=' isn't defined so we'll get the + // compiler generated default assignment operator + bool operator==(const Sub& aMargin) const { + return top == aMargin.top && right == aMargin.right && + bottom == aMargin.bottom && left == aMargin.left; + } + bool operator!=(const Sub& aMargin) const { return !(*this == aMargin); } + Sub operator+(const Sub& aMargin) const { + return Sub(top + aMargin.top, right + aMargin.right, + bottom + aMargin.bottom, left + aMargin.left); + } + Sub operator-(const Sub& aMargin) const { + return Sub(top - aMargin.top, right - aMargin.right, + bottom - aMargin.bottom, left - aMargin.left); + } + Sub operator-() const { return Sub(-top, -right, -bottom, -left); } + Sub& operator+=(const Sub& aMargin) { + top += aMargin.top; + right += aMargin.right; + bottom += aMargin.bottom; + left += aMargin.left; + return *static_cast<Sub*>(this); + } + Sub& operator-=(const Sub& aMargin) { + top -= aMargin.top; + right -= aMargin.right; + bottom -= aMargin.bottom; + left -= aMargin.left; + return *static_cast<Sub*>(this); + } + + friend std::ostream& operator<<(std::ostream& aStream, + const BaseMargin& aMargin) { + return aStream << "(t=" << aMargin.top << ", r=" << aMargin.right + << ", b=" << aMargin.bottom << ", l=" << aMargin.left << ')'; + } +}; + +} // namespace gfx +} // namespace mozilla + +#endif /* MOZILLA_GFX_BASEMARGIN_H_ */ |