layout/style/LayerAnimationInfo.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_LayerAnimationInfo_h
   8 #define mozilla_LayerAnimationInfo_h
   9
  10 #include "nsChangeHint.h"
  11 #include "nsCSSPropertyID.h"
  12 #include "nsCSSPropertyIDSet.h"
  13 #include "nsDisplayItemTypes.h"  // For nsDisplayItem::Type
  14 #include "mozilla/Array.h"
  15
  16 namespace mozilla {
  17
  18 struct LayerAnimationInfo {
  19   // Returns the corresponding display item type for |aProperty| when it is
  20   // animated on the compositor.
  21   // Returns DisplayItemType::TYPE_ZERO if |aProperty| cannot be animated on the
  22   // compositor.
  23   static DisplayItemType GetDisplayItemTypeForProperty(
  24       nsCSSPropertyID aProperty);
  25
  26   // Returns the corresponding CSS properties for |aDisplayItemType|.
  27   //
  28   // This function works only for display items tied to CSS properties that can
  29   // be animated on the compositor.
  30   static inline const nsCSSPropertyIDSet& GetCSSPropertiesFor(
  31       DisplayItemType aDisplayItemType) {
  32     static const nsCSSPropertyIDSet transformProperties =
  33         nsCSSPropertyIDSet::TransformLikeProperties();
  34     static const nsCSSPropertyIDSet opacityProperties =
  35         nsCSSPropertyIDSet{eCSSProperty_opacity};
  36     static const nsCSSPropertyIDSet backgroundColorProperties =
  37         nsCSSPropertyIDSet{eCSSProperty_background_color};
  38     static const nsCSSPropertyIDSet empty = nsCSSPropertyIDSet();
  39
  40     switch (aDisplayItemType) {
  41       case DisplayItemType::TYPE_BACKGROUND_COLOR:
  42         return backgroundColorProperties;
  43       case DisplayItemType::TYPE_OPACITY:
  44         return opacityProperties;
  45       case DisplayItemType::TYPE_TRANSFORM:
  46         return transformProperties;
  47       default:
  48         MOZ_ASSERT_UNREACHABLE(
  49             "Should not be called for display item types "
  50             "that are not able to have animations on the "
  51             "compositor");
  52         return empty;
  53     }
  54   }
  55
  56   // Returns the appropriate change hint for updating the display item for
  57   // |aDisplayItemType|.
  58   //
  59   // This function works only for display items tied to CSS properties that can
  60   // be animated on the compositor.
  61   static inline nsChangeHint GetChangeHintFor(
  62       DisplayItemType aDisplayItemType) {
  63     switch (aDisplayItemType) {
  64       case DisplayItemType::TYPE_BACKGROUND_COLOR:
  65         return nsChangeHint_RepaintFrame;
  66       case DisplayItemType::TYPE_OPACITY:
  67         return nsChangeHint_UpdateOpacityLayer;
  68       case DisplayItemType::TYPE_TRANSFORM:
  69         return nsChangeHint_UpdateTransformLayer;
  70       default:
  71         MOZ_ASSERT_UNREACHABLE(
  72             "Should not be called for display item types "
  73             "that are not able to have animations on the "
  74             "compositor");
  75         return nsChangeHint(0);
  76     }
  77   }
  78
  79   // An array of DisplayItemType corresponding to the display item that we can
  80   // animate on the compositor.
  81   //
  82   // This is used to look up the appropriate change hint in cases when
  83   // animations need updating but no other change hint is generated.
  84   static const Array<DisplayItemType,
  85                      nsCSSPropertyIDSet::CompositorAnimatableDisplayItemCount()>
  86       sDisplayItemTypes;
  87 };
  88
  89 }  // namespace mozilla
  90
  91 #endif /* !defined(mozilla_LayerAnimationInfo_h) */