gecko-dev/gfx/2d/BaseMargin.h

145 lines
3.7 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 {
/**
* Sides represents a set of physical sides.
*/
struct Sides final {
Sides() : mBits(0) {}
explicit Sides(SideBits aSideBits)
{
MOZ_ASSERT((aSideBits & ~eSideBitsAll) == 0, "illegal side bits");
mBits = aSideBits;
}
bool IsEmpty() const { return mBits == 0; }
bool Top() const { return mBits & eSideBitsTop; }
bool Right() const { return mBits & eSideBitsRight; }
bool Bottom() const { return mBits & eSideBitsBottom; }
bool Left() const { return mBits & eSideBitsLeft; }
bool Contains(SideBits aSideBits) const
{
MOZ_ASSERT((aSideBits & ~eSideBitsAll) == 0, "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:
uint8_t 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>
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.
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 + int(aSide));
}
T Side(SideT aSide) const {
// This is ugly!
return *(&top + int(aSide));
}
void ApplySkipSides(Sides aSkipSides)
{
if (aSkipSides.Top()) {
top = 0;
}
if (aSkipSides.Right()) {
right = 0;
}
if (aSkipSides.Bottom()) {
bottom = 0;
}
if (aSkipSides.Left()) {
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_ */