gfx/2d/Helpers.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef MOZILLA_GFX_2D_HELPERS_H_
   8 #define MOZILLA_GFX_2D_HELPERS_H_
   9
  10 #include "2D.h"
  11
  12 namespace mozilla {
  13 namespace gfx {
  14
  15 class AutoRestoreTransform final {
  16  public:
  17   AutoRestoreTransform() = default;
  18
  19   explicit AutoRestoreTransform(DrawTarget* aTarget)
  20       : mDrawTarget(aTarget), mOldTransform(aTarget->GetTransform()) {}
  21
  22   void Init(DrawTarget* aTarget) {
  23     MOZ_ASSERT(!mDrawTarget || aTarget == mDrawTarget);
  24     if (!mDrawTarget) {
  25       mDrawTarget = aTarget;
  26       mOldTransform = aTarget->GetTransform();
  27     }
  28   }
  29
  30   ~AutoRestoreTransform() {
  31     if (mDrawTarget) {
  32       mDrawTarget->SetTransform(mOldTransform);
  33     }
  34   }
  35
  36  private:
  37   RefPtr<DrawTarget> mDrawTarget;
  38   Matrix mOldTransform;
  39 };
  40
  41 class AutoPopClips final {
  42  public:
  43   explicit AutoPopClips(DrawTarget* aTarget)
  44       : mDrawTarget(aTarget), mPushCount(0) {
  45     MOZ_ASSERT(mDrawTarget);
  46   }
  47
  48   ~AutoPopClips() { PopAll(); }
  49
  50   void PushClip(const Path* aPath) {
  51     mDrawTarget->PushClip(aPath);
  52     ++mPushCount;
  53   }
  54
  55   void PushClipRect(const Rect& aRect) {
  56     mDrawTarget->PushClipRect(aRect);
  57     ++mPushCount;
  58   }
  59
  60   void PopClip() {
  61     MOZ_ASSERT(mPushCount > 0);
  62     mDrawTarget->PopClip();
  63     --mPushCount;
  64   }
  65
  66   void PopAll() {
  67     while (mPushCount-- > 0) {
  68       mDrawTarget->PopClip();
  69     }
  70   }
  71
  72  private:
  73   RefPtr<DrawTarget> mDrawTarget;
  74   int32_t mPushCount;
  75 };
  76
  77 }  // namespace gfx
  78 }  // namespace mozilla
  79
  80 #endif  // MOZILLA_GFX_2D_HELPERS_H_