dom/ipc/EffectsInfo.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_dom_EffectsInfo_h
   8 #define mozilla_dom_EffectsInfo_h
   9
  10 #include "nsRect.h"
  11
  12 namespace mozilla::dom {
  13
  14 /**
  15  * An EffectsInfo contains information for a remote browser about the graphical
  16  * effects that are being applied to it by ancestor browsers in different
  17  * processes.
  18  */
  19 class EffectsInfo {
  20  public:
  21   EffectsInfo() { *this = EffectsInfo::FullyHidden(); }
  22
  23   static EffectsInfo VisibleWithinRect(
  24       const nsRect& aVisibleRect, const Scale2D& aRasterScale,
  25       const ParentLayerToScreenScale2D& aTransformToAncestorScale) {
  26     return EffectsInfo{aVisibleRect, aRasterScale, aTransformToAncestorScale};
  27   }
  28   static EffectsInfo FullyHidden() {
  29     return EffectsInfo{nsRect(), Scale2D(), ParentLayerToScreenScale2D()};
  30   }
  31
  32   bool operator==(const EffectsInfo& aOther) {
  33     return mVisibleRect == aOther.mVisibleRect &&
  34            mRasterScale == aOther.mRasterScale &&
  35            mTransformToAncestorScale == aOther.mTransformToAncestorScale;
  36   }
  37   bool operator!=(const EffectsInfo& aOther) { return !(*this == aOther); }
  38
  39   bool IsVisible() const { return !mVisibleRect.IsEmpty(); }
  40
  41   // The visible rect of this browser relative to the root frame. If this is
  42   // empty then the browser can be considered invisible.
  43   nsRect mVisibleRect;
  44   // The desired scale factors to apply to rasterized content to match
  45   // transforms applied in ancestor browsers. This gets propagated into the
  46   // scale in StackingContextHelper.
  47   Scale2D mRasterScale;
  48   // TransformToAncestorScale to be set on FrameMetrics. It includes CSS
  49   // transform scales and cumulative presshell resolution.
  50   ParentLayerToScreenScale2D mTransformToAncestorScale;
  51   // The difference between mScaleX/Y and mTransformToAncestorScale is the way
  52   // that CSS transforms contribute to the scale. mTransformToAncestorScale
  53   // includes the exact scale factors of the combined CSS transform whereas
  54   // mScaleX/Y tries to take into account animating transform scales by picking
  55   // a larger scale so that we don't have to re-rasterize every frame but rather
  56   // we can just scale down  content rasterized on a previous frame.
  57
  58   // If you add new fields here, you must also update operator== and
  59   // TabMessageUtils.
  60
  61  private:
  62   EffectsInfo(const nsRect& aVisibleRect, const Scale2D& aRasterScale,
  63               const ParentLayerToScreenScale2D& aTransformToAncestorScale)
  64       : mVisibleRect(aVisibleRect),
  65         mRasterScale(aRasterScale),
  66         mTransformToAncestorScale(aTransformToAncestorScale) {}
  67 };
  68
  69 }  // namespace mozilla::dom
  70
  71 #endif  // mozilla_dom_EffectsInfo_h