gecko/gfx/2d/BaseMargin.h

94 lines
2.6 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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 "Types.h"
namespace mozilla {
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>
struct BaseMargin {
typedef mozilla::css::Side SideT;
// Do not change the layout of these members; the Side() methods below
// depend on this order.
T top, right, bottom, left;
// Constructors
BaseMargin() : top(0), right(0), bottom(0), left(0) {}
BaseMargin(T aTop, T aRight, T aBottom, T aLeft) :
top(aTop), right(aRight), bottom(aBottom), left(aLeft) {}
void SizeTo(T aTop, T aRight, T aBottom, T aLeft)
{
top = aTop; right = aRight; bottom = aBottom; left = aLeft;
}
T LeftRight() const { return left + right; }
T TopBottom() const { return top + bottom; }
T& Side(SideT aSide) {
// This is ugly!
return *(&top + T(aSide));
}
T Side(SideT aSide) const {
// This is ugly!
return *(&top + T(aSide));
}
void ApplySkipSides(int aSkipSides)
{
if (aSkipSides & (1 << mozilla::css::eSideTop)) {
top = 0;
}
if (aSkipSides & (1 << mozilla::css::eSideRight)) {
right = 0;
}
if (aSkipSides & (1 << mozilla::css::eSideBottom)) {
bottom = 0;
}
if (aSkipSides & (1 << mozilla::css::eSideLeft)) {
left = 0;
}
}
// 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 Sub& aMargin) {
top += aMargin.top;
right += aMargin.right;
bottom += aMargin.bottom;
left += aMargin.left;
return *static_cast<Sub*>(this);
}
};
}
}
#endif /* MOZILLA_GFX_BASEMARGIN_H_ */