dom/animation/ViewTimeline.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 file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_ViewTimeline_h
   8 #define mozilla_dom_ViewTimeline_h
   9
  10 #include "mozilla/dom/ScrollTimeline.h"
  11
  12 namespace mozilla {
  13 class ScrollContainerFrame;
  14 }  // namespace mozilla
  15
  16 namespace mozilla::dom {
  17
  18 /*
  19  * A view progress timeline is a segment of a scroll progress timeline that are
  20  * scoped to the scroll positions in which any part of the associated element’s
  21  * principal box intersects its nearest ancestor scrollport. So ViewTimeline
  22  * is a special case of ScrollTimeline.
  23  */
  24 class ViewTimeline final : public ScrollTimeline {
  25   template <typename T, typename... Args>
  26   friend already_AddRefed<T> mozilla::MakeAndAddRef(Args&&... aArgs);
  27
  28  public:
  29   NS_DECL_ISUPPORTS_INHERITED
  30   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ViewTimeline, ScrollTimeline)
  31
  32   ViewTimeline() = delete;
  33
  34   // Note: |aSubject| is used as the subject which specifies view-timeline-name
  35   // property, and we use this subject to look up its nearest scroll container.
  36   static already_AddRefed<ViewTimeline> MakeNamed(
  37       Document* aDocument, Element* aSubject, PseudoStyleType aPseudoType,
  38       const StyleViewTimeline& aStyleTimeline);
  39
  40   static already_AddRefed<ViewTimeline> MakeAnonymous(
  41       Document* aDocument, const NonOwningAnimationTarget& aTarget,
  42       StyleScrollAxis aAxis, const StyleViewTimelineInset& aInset);
  43
  44   JSObject* WrapObject(JSContext* aCx,
  45                        JS::Handle<JSObject*> aGivenProto) override {
  46     return nullptr;
  47   }
  48
  49   bool IsViewTimeline() const override { return true; }
  50
  51   void ReplacePropertiesWith(Element* aSubjectElement,
  52                              PseudoStyleType aPseudoType,
  53                              const StyleViewTimeline& aNew);
  54
  55  private:
  56   ~ViewTimeline() = default;
  57   ViewTimeline(Document* aDocument, const Scroller& aScroller,
  58                StyleScrollAxis aAxis, Element* aSubject,
  59                PseudoStyleType aSubjectPseudoType,
  60                const StyleViewTimelineInset& aInset)
  61       : ScrollTimeline(aDocument, aScroller, aAxis),
  62         mSubject(aSubject),
  63         mSubjectPseudoType(aSubjectPseudoType),
  64         mInset(aInset) {}
  65
  66   Maybe<ScrollOffsets> ComputeOffsets(
  67       const ScrollContainerFrame* aScrollContainerFrame,
  68       layers::ScrollDirection aOrientation) const override;
  69
  70   ScrollOffsets ComputeInsets(const ScrollContainerFrame* aScrollContainerFrame,
  71                               layers::ScrollDirection aOrientation) const;
  72
  73   // The subject element.
  74   // 1. For view(), the subject element is the animation target.
  75   // 2. For view-timeline property, the subject element is the element who
  76   //    defines this property.
  77   RefPtr<Element> mSubject;
  78   PseudoStyleType mSubjectPseudoType;
  79
  80   // FIXME: Bug 1817073. view-timeline-inset is an animatable property. However,
  81   // the inset from view() is not animatable, so for named view timeline, this
  82   // value depends on the animation style. Therefore, we have to check its style
  83   // value when using it. For now, in order to simplify the implementation, we
  84   // make |mInset| be fixed.
  85   StyleViewTimelineInset mInset;
  86 };
  87
  88 }  // namespace mozilla::dom
  89
  90 #endif  // mozilla_dom_ViewTimeline_h