Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Avoid NullReferenceException in Gestures.PointerReleased #15117

Merged
merged 5 commits into from
Apr 5, 2024
Merged

Avoid NullReferenceException in Gestures.PointerReleased #15117

Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
0c965be
refs #14249 Avoid NullReferenceException in Gestures.PointerReleased
zabolotnev Mar 25, 2024
adc04de
refs #14249 Track current gesture state with single readonly struct
zabolotnev Mar 26, 2024
399235e
Update from review
zabolotnev Mar 26, 2024
ebc9c23
Merge branch 'master' into fix/NRE_in_Gestures_PointerReleased
zabolotnev Mar 26, 2024
b44b66d
Moved the last click location from the GestureState record to a separ…
zabolotnev Mar 29, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
58 changes: 29 additions & 29 deletions src/Avalonia.Base/Input/Gestures.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,8 +10,17 @@ namespace Avalonia.Input
{
public static class Gestures
{
private static bool s_isDoubleTapped = false;
private static bool s_isHolding;
private record struct GestureState(GestureStateType Type, IPointer Pointer);
private enum GestureStateType
{
Pending,
Holding,
DoubleTapped
}

private static GestureState? s_gestureState = null;
private static readonly WeakReference<object?> s_lastPress = new WeakReference<object?>(null);
private static Point s_lastPressPoint;
private static CancellationTokenSource? s_holdCancellationToken;

/// <summary>
Expand Down Expand Up @@ -65,10 +74,6 @@ public static class Gestures
RoutedEvent.Register<PointerDeltaEventArgs>(
"PointerSwipeGesture", RoutingStrategies.Bubble, typeof(Gestures));

private static readonly WeakReference<object?> s_lastPress = new WeakReference<object?>(null);
private static Point s_lastPressPoint;
private static IPointer? s_lastHeldPointer;

public static readonly RoutedEvent<PinchEventArgs> PinchEvent =
RoutedEvent.Register<PinchEventArgs>(
"PinchEvent", RoutingStrategies.Bubble, typeof(Gestures));
Expand Down Expand Up @@ -225,26 +230,23 @@ private static void PointerPressed(RoutedEventArgs ev)
var e = (PointerPressedEventArgs)ev;
var visual = (Visual)ev.Source;

if(s_lastHeldPointer != null)
if(s_gestureState != null)
{
if(s_isHolding && ev.Source is Interactive i)
if(s_gestureState.Value.Type == GestureStateType.Holding && ev.Source is Interactive i)
{
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Cancelled, s_lastPressPoint, s_lastHeldPointer.Type, e));
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Cancelled, s_lastPressPoint, s_gestureState.Value.Pointer.Type, e));
}
s_holdCancellationToken?.Cancel();
s_holdCancellationToken?.Dispose();
s_holdCancellationToken = null;

s_lastHeldPointer = null;
s_gestureState = null;
}

s_isHolding = false;

if (e.ClickCount % 2 == 1)
{
s_isDoubleTapped = false;
s_gestureState = new GestureState(GestureStateType.Pending, e.Pointer);
s_lastPress.SetTarget(ev.Source);
s_lastHeldPointer = e.Pointer;
s_lastPressPoint = e.GetPosition((Visual)ev.Source);
s_holdCancellationToken = new CancellationTokenSource();
var token = s_holdCancellationToken.Token;
Expand All @@ -254,10 +256,10 @@ private static void PointerPressed(RoutedEventArgs ev)
{
DispatcherTimer.RunOnce(() =>
{
if (!token.IsCancellationRequested && e.Source is InputElement i && GetIsHoldingEnabled(i) && (e.Pointer.Type != PointerType.Mouse || GetIsHoldWithMouseEnabled(i)))
if (s_gestureState != null && !token.IsCancellationRequested && e.Source is InputElement i && GetIsHoldingEnabled(i) && (e.Pointer.Type != PointerType.Mouse || GetIsHoldWithMouseEnabled(i)))
{
s_isHolding = true;
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Started, s_lastPressPoint, s_lastHeldPointer.Type, e));
s_gestureState = new GestureState(GestureStateType.Holding, s_gestureState.Value.Pointer);
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Started, s_lastPressPoint, s_gestureState.Value.Pointer.Type, e));
}
}, settings.HoldWaitDuration);
}
Expand All @@ -268,7 +270,7 @@ private static void PointerPressed(RoutedEventArgs ev)
target == e.Source &&
e.Source is Interactive i)
{
s_isDoubleTapped = true;
s_gestureState = new GestureState(GestureStateType.DoubleTapped, e.Pointer);
i.RaiseEvent(new TappedEventArgs(DoubleTappedEvent, e));
}
}
Expand All @@ -294,23 +296,22 @@ e.InitialPressMouseButton is MouseButton.Left or MouseButton.Right &&

if (tapRect.ContainsExclusive(point.Position))
{
if (s_isHolding)
if (s_gestureState?.Type == GestureStateType.Holding)
{
s_isHolding = false;
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Completed, s_lastPressPoint, s_lastHeldPointer!.Type, e));
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Completed, s_lastPressPoint, s_gestureState.Value.Pointer.Type, e));
}
else if (e.InitialPressMouseButton == MouseButton.Right)
{
i.RaiseEvent(new TappedEventArgs(RightTappedEvent, e));
}
//s_isDoubleTapped needed here to prevent invoking Tapped event when DoubleTapped is called.
//GestureStateType.DoubleTapped needed here to prevent invoking Tapped event when DoubleTapped is called.
//This behaviour matches UWP behaviour.
else if (s_isDoubleTapped == false)
else if (s_gestureState?.Type != GestureStateType.DoubleTapped)
{
i.RaiseEvent(new TappedEventArgs(TappedEvent, e));
}
}
s_lastHeldPointer = null;
s_gestureState = null;
}

s_holdCancellationToken?.Cancel();
Expand All @@ -326,7 +327,7 @@ private static void PointerMoved(RoutedEventArgs ev)
var e = (PointerEventArgs)ev;
if (s_lastPress.TryGetTarget(out var target))
{
if (e.Pointer == s_lastHeldPointer && ev.Source is Interactive i)
if (e.Pointer == s_gestureState?.Pointer && ev.Source is Interactive i)
{
var point = e.GetCurrentPoint((Visual)target);
var settings = ((IInputRoot?)i.GetVisualRoot())?.PlatformSettings;
Expand All @@ -339,18 +340,17 @@ private static void PointerMoved(RoutedEventArgs ev)
return;
}

if (s_isHolding)
if (s_gestureState.Value.Type == GestureStateType.Holding)
{
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Cancelled, s_lastPressPoint, s_lastHeldPointer!.Type, e));
maxkatz6 marked this conversation as resolved.
Show resolved Hide resolved
s_lastHeldPointer = null;
i.RaiseEvent(new HoldingRoutedEventArgs(HoldingState.Cancelled, s_lastPressPoint, s_gestureState.Value.Pointer.Type, e));
}
}
}

s_holdCancellationToken?.Cancel();
s_holdCancellationToken?.Dispose();
s_holdCancellationToken = null;
s_isHolding = false;
s_gestureState = null;
}
}
}
Expand Down
Loading