tor-browser

BaseMargin.h (5501B)

---

/* -*- 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 Intersects(SideBits aSideBits) const { return bool(mBits & aSideBits); }
 bool Top() const { return Intersects(SideBits::eTop); }
 bool Right() const { return Intersects(SideBits::eRight); }
 bool Bottom() const { return Intersects(SideBits::eBottom); }
 bool Left() const { return Intersects(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
 constexpr BaseMargin() : top(0), right(0), bottom(0), left(0) {}
 constexpr 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);
 }

 bool IsAll(Coord aCoord) const {
   return left == aCoord && top == aCoord && right == aCoord &&
          bottom == aCoord;
 }

 bool IsAllZero() const { return IsAll(0); }
 bool IsAllEqual() const { return IsAll(top); }

 // 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_ */