SmoothScrollAnimation.h

Enable keyboard shortcuts

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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_layers_SmoothScrollAnimation_h_

#define mozilla_layers_SmoothScrollAnimation_h_

#include "AsyncPanZoomAnimation.h"

#include "InputData.h"

#include "ScrollPositionUpdate.h"

#include "mozilla/AlreadyAddRefed.h"

#include "mozilla/RelativeTo.h"

#include "mozilla/ScrollOrigin.h"

#include "mozilla/layers/APZPublicUtils.h"

#include "mozilla/layers/KeyboardScrollAction.h"

namespace mozilla {

class ScrollAnimationPhysics;

namespace layers {

class AsyncPanZoomController;

class SmoothScrollAnimation : public AsyncPanZoomAnimation {

 public:

  using ScrollAnimationKind = apz::ScrollAnimationKind;

  // Create a SmoothScrollAnimation of kind Smooth or SmoothMsd.

  // The origin is ignored for SmoothMsd animations.

  static already_AddRefed<SmoothScrollAnimation> Create(

      AsyncPanZoomController& aApzc, ScrollAnimationKind aKind,

      ViewportType aViewportToScroll, ScrollOrigin aOrigin);

  // Create a SmoothScrollAnimation of kind Keyboard.

  static already_AddRefed<SmoothScrollAnimation> CreateForKeyboard(

      AsyncPanZoomController& aApzc, ScrollOrigin aOrigin);

  // Create a SmoothScrollAnimation of kind Wheel.

  static already_AddRefed<SmoothScrollAnimation> CreateForWheel(

      AsyncPanZoomController& aApzc,

      ScrollWheelInput::ScrollDeltaType aDeltaType);

  void UpdateDestinationAndSnapTargets(

      TimeStamp aTime, const nsPoint& aDestination,

      const nsSize& aCurrentVelocity, ScrollSnapTargetIds&& aSnapTargetIds,

      ScrollTriggeredByScript aTriggeredByScript);

  SmoothScrollAnimation* AsSmoothScrollAnimation() override;

  bool WasTriggeredByScript() const override {

    return mTriggeredByScript == ScrollTriggeredByScript::Yes;

  ScrollAnimationKind Kind() const { return mKind; }

  ViewportType ViewportToScroll() const { return mViewportToScroll; }

  ScrollSnapTargetIds TakeSnapTargetIds() { return std::move(mSnapTargetIds); }

  ScrollOrigin GetScrollOrigin() const;

  static ScrollOrigin GetScrollOriginForAction(

      KeyboardScrollAction::KeyboardScrollActionType aAction);

  bool DoSample(FrameMetrics& aFrameMetrics,

                const TimeDuration& aDelta) override;

  bool HandleScrollOffsetUpdate(const Maybe<CSSPoint>& aRelativeDelta) override;

  void UpdateDelta(TimeStamp aTime, const nsPoint& aDelta,

                   const nsSize& aCurrentVelocity);

  void UpdateDestination(TimeStamp aTime, const nsPoint& aDestination,

                         const nsSize& aCurrentVelocity);

  CSSPoint GetDestination() const {

    return CSSPoint::FromAppUnits(mFinalDestination);

  // If we need to perform an animation of the same kind and the specified

  // parameters, can we extend this existing animation?

  bool CanExtend(ViewportType aViewportToScroll, ScrollOrigin aOrigin) const;

 private:

  SmoothScrollAnimation(ScrollAnimationKind aKind,

                        AsyncPanZoomController& aApzc,

                        ViewportType aViewportToScroll, ScrollOrigin aOrigin);

  void Update(TimeStamp aTime, const nsSize& aCurrentVelocity);

  CSSPoint GetViewportOffset(const FrameMetrics& aMetrics) const;

  ScrollAnimationKind mKind;

  // Whether the animation is scroling the visual viewport or the layout

  // viewport.

  ViewportType mViewportToScroll;

  AsyncPanZoomController& mApzc;

  UniquePtr<ScrollAnimationPhysics> mAnimationPhysics;

  nsPoint mFinalDestination;

  // If a direction is forced to overscroll, it means it's axis in that

  // direction is locked, and scroll in that direction is treated as overscroll

  // of an equal amount, which, for example, may then bubble up a scroll action

  // to its parent, or may behave as whatever an overscroll occurence requires

  // to behave

  Maybe<ScrollDirection> mDirectionForcedToOverscroll;

  ScrollOrigin mOrigin;

  // These fields are only used for animations of kind Smooth and SmoothMsd.

  ScrollSnapTargetIds mSnapTargetIds;

  ScrollTriggeredByScript mTriggeredByScript;

};

}  // namespace layers

}  // namespace mozilla

#endif  // mozilla_layers_SmoothScrollAnimation_h_