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Merge pull request PCL-Community#123 from MinecraftYJQ/main
feat: 添加页面平滑滚动
2 parents b88eb08 + fe4c607 commit eaa0d7f

16 files changed

+3252
-2
lines changed

‎PCL.CompositionScroll/CompositionScrollContentPresenter.cs‎

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‎PCL.CompositionScroll/Interactions/Factory.cs‎

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using Avalonia.Rendering.Composition;
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namespace CompositionScroll.Interactions
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{
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public static class Factory
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{
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public static InteractionTracker CreateInteractionTracker(this Compositor compositor)
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{
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return compositor.CreateInteractionTracker(null);
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}
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public static InteractionTracker CreateInteractionTracker(this Compositor compositor, IInteractionTrackerOwner owner)
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{
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var tracker = new InteractionTracker(compositor, owner);
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tracker.Init();
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return tracker;
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}
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public static InteractionTrackerInertiaRestingValue CreateInteractionTrackerInertiaRestingValue(this Compositor compositor)
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=> InteractionTrackerInertiaRestingValue.Create(compositor);
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}
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}

‎PCL.CompositionScroll/Interactions/IInteractionTrackerOwner.cs‎

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using Avalonia;
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namespace CompositionScroll.Interactions
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{
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public interface IInteractionTrackerOwner
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{
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void ValuesChanged(InteractionTracker sender, InteractionTrackerValuesChangedArgs args);
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void IdleStateEntered(InteractionTracker sender, InteractionTrackerIdleStateEnteredArgs args);
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void InertiaStateEntered(InteractionTracker sender, InteractionTrackerInertiaStateEnteredArgs args);
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void InteractingStateEntered(InteractionTracker sender, InteractionTrackerInteractingStateEnteredArgs args);
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}
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public sealed class InteractionTrackerValuesChangedArgs
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{
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internal InteractionTrackerValuesChangedArgs(Vector3D position, long requestId)
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{
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Position = position;
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RequestId = requestId;
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}
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public Vector3D Position { get; }
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public long RequestId { get; }
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}
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public sealed class InteractionTrackerIdleStateEnteredArgs
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{
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internal InteractionTrackerIdleStateEnteredArgs(long requestId)
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{
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RequestId = requestId;
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}
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public long RequestId { get; }
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}
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public sealed class InteractionTrackerInertiaStateEnteredArgs
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{
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internal InteractionTrackerInertiaStateEnteredArgs(bool fromImpulse, Vector3D? modifiedRestingPosition, Vector3D naturalRestingPosition, Vector3D positionVelocity, long requestId)
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{
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IsInertiaFromImpulse = fromImpulse;
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ModifiedRestingPosition = modifiedRestingPosition;
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NaturalRestingPosition = naturalRestingPosition;
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PositionVelocityInPixelsPerSecond = positionVelocity;
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RequestId = requestId;
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}
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public bool IsInertiaFromImpulse { get; }
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public Vector3D? ModifiedRestingPosition { get; }
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public Vector3D NaturalRestingPosition { get; }
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public Vector3D PositionVelocityInPixelsPerSecond { get; }
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public long RequestId { get; }
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}
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public class InteractionTrackerInteractingStateEnteredArgs
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{
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internal InteractionTrackerInteractingStateEnteredArgs(long requestId)
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{
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RequestId = requestId;
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}
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public long RequestId { get; }
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}
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}

‎PCL.CompositionScroll/Interactions/InteractionSource.cs‎

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using Avalonia;
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using Avalonia.Input;
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using Avalonia.Input.GestureRecognizers;
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using System;
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namespace CompositionScroll.Interactions
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{
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public sealed class InteractionSource : GestureRecognizer
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{
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private static int Id = 1;
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private static int GetId() => Id++;
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private int _interactionId;
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private IPointer _tracking;
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private Visual _rootTarget;
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private Point _pointerPressedPoint;
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private VelocityTracker _velocityTracker;
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private bool _scrolling;
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public InteractionSource(IInputElement target)
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{
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target.PointerWheelChanged += Target_PointerWheelChanged;
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}
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private InteractionTracker Tracker { get; set; }
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public bool CanHorizontallyScroll { get; set; } = false;
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public bool CanVerticallyScroll { get; set; } = true;
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public bool IsScrollInertiaEnabled { get; set; } = true;
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public ScrollFeaturesEnum ScrollFeatures { get; set; } = ScrollFeaturesEnum.None;
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public double ScrollStartDistance { get; set; } = 10;
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private bool CanAny(ScrollFeaturesEnum feature) => (feature & ScrollFeatures) != ScrollFeaturesEnum.None;
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private void Target_PointerWheelChanged(object sender, PointerWheelEventArgs e)
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{
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if (Tracker == null)
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return;
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var delta = e.Delta;
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if (CanAny(ScrollFeaturesEnum.WheelSwapDirections))
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{
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delta = new Vector(delta.Y, delta.X);
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}
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if (e.KeyModifiers == KeyModifiers.Shift)
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{
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delta = new Vector(delta.Y, delta.X);
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}
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delta = FitVector(delta, CanHorizontallyScroll, CanVerticallyScroll);
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delta = delta.Negate();
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delta = delta * 50;
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Tracker.AnimatePositionBy(new Vector3D(delta.X, delta.Y, 0));
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e.Handled = true;
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}
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protected override void PointerPressed(PointerPressedEventArgs e)
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{
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if (e.Pointer.Type == PointerType.Mouse && !CanAny(ScrollFeaturesEnum.MousePressedScroll))
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return;
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EndGesture();
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_tracking = e.Pointer;
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_interactionId = GetId();
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_rootTarget = (Visual)((Target as Visual)?.VisualRoot);
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_pointerPressedPoint = e.GetPosition(_rootTarget);
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_velocityTracker = new VelocityTracker();
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_velocityTracker.AddPosition(TimeSpan.FromMilliseconds(e.Timestamp), default);
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BeginUserInteraction();
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}
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protected override void PointerMoved(PointerEventArgs e)
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{
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if (e.Pointer != _tracking)
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return;
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var rootPoint = e.GetPosition(_rootTarget);
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if (!_scrolling)
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{
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if (CanHorizontallyScroll && Math.Abs(_pointerPressedPoint.X - rootPoint.X) > ScrollStartDistance)
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_scrolling = true;
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if (CanVerticallyScroll && Math.Abs(_pointerPressedPoint.Y - rootPoint.Y) > ScrollStartDistance)
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_scrolling = true;
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if (_scrolling)
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{
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Capture(_tracking);
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}
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}
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if (_scrolling)
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{
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Vector delta = _pointerPressedPoint - rootPoint;
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delta = FitVector(delta, CanHorizontallyScroll, CanVerticallyScroll);
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_velocityTracker?.AddPosition(TimeSpan.FromMilliseconds(e.Timestamp), delta);
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UserInteraction(delta);
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e.Handled = true;
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}
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}
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protected override void PointerReleased(PointerReleasedEventArgs e)
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{
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if (e.Pointer != _tracking)
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return;
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var inertia = _velocityTracker?.GetFlingVelocity().PixelsPerSecond ?? Vector.Zero;
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inertia = FitVector(inertia, CanHorizontallyScroll, CanVerticallyScroll);
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if (_scrolling &&
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IsScrollInertiaEnabled &&
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(e.Pointer.Type != PointerType.Mouse || CanAny(ScrollFeaturesEnum.MousePressedScrollEnertia)))
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{
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EndGesture(inertia);
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}
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else
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{
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EndGesture();
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}
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}
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protected override void PointerCaptureLost(IPointer pointer)
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{
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if (pointer != _tracking)
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return;
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EndGesture();
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}
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private void EndGesture(Vector? inertia = null)
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{
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EndUserInteraction(inertia);
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_tracking = null;
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if (_scrolling)
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{
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_scrolling = false;
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_interactionId = 0;
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_rootTarget = null;
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}
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}
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private static Vector FitVector(Vector vector, bool canHoriz, bool canVer)
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{
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if (!canHoriz)
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vector = new Point(0, vector.Y);
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if (!canVer)
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vector = new Point(vector.X, 0);
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return vector;
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}
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private void BeginUserInteraction()
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{
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Tracker.InteractionStart(_interactionId);
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}
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private void UserInteraction(Vector delta)
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{
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var delta3D = new Vector3D(delta.X, delta.Y, 0);
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Tracker.InteractionMove(_interactionId, delta3D);
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}
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private void EndUserInteraction(Vector? inertia = null)
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{
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if (inertia == null)
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Tracker.InteractionEnd(_interactionId);
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else
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{
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var inertia3D = new Vector3D(inertia.Value.X, inertia.Value.Y, 0);
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Tracker.InteractionEndWithInertia(_interactionId, inertia3D);
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}
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}
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internal void SetInteractionTracker(InteractionTracker tracker)
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{
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Tracker = tracker;
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}
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}
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}

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