gecko/gfx/2d/Helpers.h

48 lines
1.0 KiB
C++

/* -*- Mode: C++; tab-width: 20; 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_2D_HELPERS_H_
#define MOZILLA_GFX_2D_HELPERS_H_
#include "2D.h"
namespace mozilla {
namespace gfx {
class AutoRestoreTransform
{
public:
explicit AutoRestoreTransform(DrawTarget *aTarget)
: mDrawTarget(aTarget),
mOldTransform(aTarget->GetTransform())
{
}
void Init(DrawTarget *aTarget)
{
MOZ_ASSERT(!mDrawTarget || aTarget == mDrawTarget);
if (!mDrawTarget) {
mDrawTarget = aTarget;
mOldTransform = aTarget->GetTransform();
}
}
~AutoRestoreTransform()
{
if (mDrawTarget) {
mDrawTarget->SetTransform(mOldTransform);
}
}
private:
RefPtr<DrawTarget> mDrawTarget;
Matrix mOldTransform;
};
} // namespace gfx
} // namespace mozilla
#endif // MOZILLA_GFX_2D_HELPERS_H_