fix: PinchDetected event leak, false DoubleTapDetected, MinScale/MaxScale ordering; convert duration properties to TimeSpan

- Fix PinchDetected firing when IsPinchEnabled=false but IsPanEnabled=true
- Reset _tapCount/_lastTapTicks when entering Pinching state to prevent false double-tap
- Add SetScaleRange() method for atomic min/max scale configuration
- Convert LongPressDuration, ZoomAnimationDuration, FlingFrameInterval, ZoomAnimationInterval from int (ms) to TimeSpan
- Update all usages in implementation, tests, and MAUI sample
- Add tests for all bug fixes and SetScaleRange edge cases (411 total, all passing)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: mattleibow

samples/SkiaSharpDemo/Demos/Gestures/GesturePage.xaml.cs

@@ -508,20 +508,20 @@ private async void OnSettingsClicked(object? sender, EventArgs e)
 		AddSlider(layout, "Touch Slop", "px", 1, 50, _tracker.Options.TouchSlop, v => _tracker.Options.TouchSlop = v);
 		AddSlider(layout, "Double Tap Slop", "px", 10, 200, _tracker.Options.DoubleTapSlop, v => _tracker.Options.DoubleTapSlop = v);
 		AddSlider(layout, "Fling Threshold", "px/s", 50, 1000, _tracker.Options.FlingThreshold, v => _tracker.Options.FlingThreshold = v);
-		AddSliderInt(layout, "Long Press Duration", "ms", 100, 2000, _tracker.Options.LongPressDuration, v => _tracker.Options.LongPressDuration = v);
+		AddSliderInt(layout, "Long Press Duration", "ms", 100, 2000, (int)_tracker.Options.LongPressDuration.TotalMilliseconds, v => _tracker.Options.LongPressDuration = TimeSpan.FromMilliseconds(v));
 
 		// --- Fling Settings ---
 		layout.Children.Add(new Label { Text = "Fling Settings", FontAttributes = FontAttributes.Bold, FontSize = 16, Margin = new Thickness(0, 10, 0, 0) });
 
 		AddSlider(layout, "Friction", "", 0.01f, 0.5f, _tracker.Options.FlingFriction, v => _tracker.Options.FlingFriction = v, "F3");
 		AddSlider(layout, "Min Velocity", "px/s", 1, 50, _tracker.Options.FlingMinVelocity, v => _tracker.Options.FlingMinVelocity = v);
-		AddSliderInt(layout, "Frame Interval", "ms", 8, 50, _tracker.Options.FlingFrameInterval, v => _tracker.Options.FlingFrameInterval = v);
+		AddSliderInt(layout, "Frame Interval", "ms", 8, 50, (int)_tracker.Options.FlingFrameInterval.TotalMilliseconds, v => _tracker.Options.FlingFrameInterval = TimeSpan.FromMilliseconds(v));
 
 		// --- Zoom Settings ---
 		layout.Children.Add(new Label { Text = "Zoom Settings", FontAttributes = FontAttributes.Bold, FontSize = 16, Margin = new Thickness(0, 10, 0, 0) });
 
 		AddSlider(layout, "Double Tap Zoom", "x", 1.5f, 5, _tracker.Options.DoubleTapZoomFactor, v => _tracker.Options.DoubleTapZoomFactor = v, "F1");
-		AddSliderInt(layout, "Zoom Animation", "ms", 50, 1000, _tracker.Options.ZoomAnimationDuration, v => _tracker.Options.ZoomAnimationDuration = v);
+		AddSliderInt(layout, "Zoom Animation", "ms", 50, 1000, (int)_tracker.Options.ZoomAnimationDuration.TotalMilliseconds, v => _tracker.Options.ZoomAnimationDuration = TimeSpan.FromMilliseconds(v));
 		AddSlider(layout, "Scroll Zoom Factor", "", 0.01f, 0.5f, _tracker.Options.ScrollZoomFactor, v => _tracker.Options.ScrollZoomFactor = v, "F3");
 		AddSlider(layout, "Min Scale", "x", 0.1f, 1, _tracker.Options.MinScale, v => _tracker.Options.MinScale = v, "F2");
 		AddSlider(layout, "Max Scale", "x", 2, 20, _tracker.Options.MaxScale, v => _tracker.Options.MaxScale = v, "F1");

source/SkiaSharp.Extended/Gestures/SKGestureDetector.cs

@@ -235,6 +235,8 @@ public bool ProcessTouchDown(long id, SKPoint location, bool isMouse = false)
 			if (touchPoints.Length >= 2)
 			{
 				StopLongPressTimer();
+				_tapCount = 0;
+				_lastTapTicks = 0;
 				_pinchState = PinchState.FromLocations(touchPoints);
 				_gestureState = GestureState.Pinching;
 			}
@@ -367,7 +369,7 @@ public bool ProcessTouchUp(long id, SKPoint location, bool isMouse = false)
 		{
 			var distance = SKPoint.Distance(location, _initialTouch);
 			var duration = ticks - _touchStartTicks;
-			var maxTapDuration = storedIsMouse ? ShortClickTicks : Options.LongPressDuration * TimeSpan.TicksPerMillisecond;
+			var maxTapDuration = storedIsMouse ? ShortClickTicks : Options.LongPressDuration.Ticks;
 
 			if (distance < Options.TouchSlop && duration < maxTapDuration && !_longPressTriggered)
 			{
@@ -523,7 +525,7 @@ private void StartLongPressTimer()
 	{
 		StopLongPressTimer();
 		var token = Interlocked.Increment(ref _longPressToken);
-		var timer = new Timer(OnLongPressTimerTick, token, Options.LongPressDuration, Timeout.Infinite);
+		var timer = new Timer(OnLongPressTimerTick, token, (int)Options.LongPressDuration.TotalMilliseconds, Timeout.Infinite);
 		_longPressTimer = timer;
 	}
 

source/SkiaSharp.Extended/Gestures/SKGestureDetectorOptions.cs

@@ -16,7 +16,7 @@ public class SKGestureDetectorOptions
 	private float _touchSlop = 8f;
 	private float _doubleTapSlop = 40f;
 	private float _flingThreshold = 200f;
-	private int _longPressDuration = 500;
+	private TimeSpan _longPressDuration = TimeSpan.FromMilliseconds(500);
 
 	/// <summary>
 	/// Gets or sets the minimum movement distance, in pixels, before a touch is considered a pan gesture.
@@ -72,17 +72,16 @@ public float FlingThreshold
 	}
 
 	/// <summary>
-	/// Gets or sets the duration, in milliseconds, a touch must be held stationary before
-	/// a long press gesture is recognized.
+	/// Gets or sets the duration a touch must be held stationary before a long press gesture is recognized.
 	/// </summary>
-	/// <value>The long press duration in milliseconds. The default is <c>500</c>. Must be positive.</value>
+	/// <value>The long press duration. The default is <c>500 ms</c>. Must be positive.</value>
 	/// <exception cref="ArgumentOutOfRangeException"><paramref name="value"/> is zero or negative.</exception>
-	public int LongPressDuration
+	public TimeSpan LongPressDuration
 	{
 		get => _longPressDuration;
 		set
 		{
-			if (value <= 0)
+			if (value <= TimeSpan.Zero)
 				throw new ArgumentOutOfRangeException(nameof(value), value, "LongPressDuration must be positive.");
 			_longPressDuration = value;
 		}

source/SkiaSharp.Extended/Gestures/SKGestureTracker.cs

@@ -472,8 +472,8 @@ public void ZoomTo(float factor, SKPoint focalPoint)
 		_zoomTimer = new Timer(
 			OnZoomTimerTick,
 			token,
-			Options.ZoomAnimationInterval,
-			Options.ZoomAnimationInterval);
+			(int)Options.ZoomAnimationInterval.TotalMilliseconds,
+			(int)Options.ZoomAnimationInterval.TotalMilliseconds);
 	}
 
 	/// <summary>Stops any active zoom animation immediately.</summary>
@@ -669,7 +669,7 @@ private void OnEnginePanDetected(object? s, SKPanGestureEventArgs e)
 
 	private void OnEnginePinchDetected(object? s, SKPinchGestureEventArgs e)
 	{
-		if (IsPinchEnabled || IsPanEnabled)
+		if (IsPinchEnabled)
 			PinchDetected?.Invoke(this, e);
 
 		// Apply center movement as pan
@@ -804,8 +804,8 @@ private void StartFlingAnimation(float velocityX, float velocityY)
 		_flingTimer = new Timer(
 			OnFlingTimerTick,
 			token,
-			Options.FlingFrameInterval,
-			Options.FlingFrameInterval);
+			(int)Options.FlingFrameInterval.TotalMilliseconds,
+			(int)Options.FlingFrameInterval.TotalMilliseconds);
 	}
 
 	private void OnFlingTimerTick(object? state)
@@ -853,7 +853,7 @@ private void HandleFlingFrame()
 		TransformChanged?.Invoke(this, EventArgs.Empty);
 
 		// Apply time-scaled friction so deceleration is consistent regardless of frame rate
-		var nominalDtMs = (float)Options.FlingFrameInterval;
+		var nominalDtMs = (float)Options.FlingFrameInterval.TotalMilliseconds;
 		var decay = nominalDtMs > 0
 			? (float)Math.Pow(1.0 - Options.FlingFriction, actualDtMs / nominalDtMs)
 			: 1f - Options.FlingFriction;
@@ -900,7 +900,7 @@ private void HandleZoomFrame()
 			return;
 
 		var elapsed = TimeProvider() - _zoomStartTicks;
-		var duration = Options.ZoomAnimationDuration * TimeSpan.TicksPerMillisecond;
+		var duration = Options.ZoomAnimationDuration.Ticks;
 		var t = duration > 0 ? Math.Min(1.0, (double)elapsed / duration) : 1.0;
 
 		// CubicOut easing: 1 - (1 - t)^3

source/SkiaSharp.Extended/Gestures/SKGestureTrackerOptions.cs

@@ -16,12 +16,12 @@ public class SKGestureTrackerOptions : SKGestureDetectorOptions
 	private float _minScale = 0.1f;
 	private float _maxScale = 10f;
 	private float _doubleTapZoomFactor = 2f;
-	private int _zoomAnimationDuration = 250;
+	private TimeSpan _zoomAnimationDuration = TimeSpan.FromMilliseconds(250);
 	private float _scrollZoomFactor = 0.1f;
 	private float _flingFriction = 0.08f;
 	private float _flingMinVelocity = 5f;
-	private int _flingFrameInterval = 16;
-	private int _zoomAnimationInterval = 16;
+	private TimeSpan _flingFrameInterval = TimeSpan.FromMilliseconds(16);
+	private TimeSpan _zoomAnimationInterval = TimeSpan.FromMilliseconds(16);
 
 	/// <summary>
 	/// Gets or sets the minimum allowed zoom scale.
@@ -59,6 +59,30 @@ public float MaxScale
 		}
 	}
 
+	/// <summary>
+	/// Sets both <see cref="MinScale"/> and <see cref="MaxScale"/> atomically,
+	/// avoiding ordering-dependent validation errors when the desired range lies
+	/// entirely outside the current default range of [0.1, 10].
+	/// </summary>
+	/// <param name="minScale">The minimum scale value. Must be positive and less than <paramref name="maxScale"/>.</param>
+	/// <param name="maxScale">The maximum scale value. Must be positive and greater than <paramref name="minScale"/>.</param>
+	/// <exception cref="ArgumentOutOfRangeException">
+	/// Thrown when <paramref name="minScale"/> is less than or equal to zero, <paramref name="maxScale"/> is less than
+	/// or equal to zero, or <paramref name="minScale"/> is greater than or equal to <paramref name="maxScale"/>.
+	/// </exception>
+	public void SetScaleRange(float minScale, float maxScale)
+	{
+		if (minScale <= 0)
+			throw new ArgumentOutOfRangeException(nameof(minScale), minScale, "MinScale must be positive.");
+		if (maxScale <= 0)
+			throw new ArgumentOutOfRangeException(nameof(maxScale), maxScale, "MaxScale must be positive.");
+		if (minScale >= maxScale)
+			throw new ArgumentOutOfRangeException(nameof(minScale), minScale, "MinScale must be less than MaxScale.");
+
+		_minScale = minScale;
+		_maxScale = maxScale;
+	}
+
 	/// <summary>
 	/// Gets or sets the multiplicative zoom factor applied when a double-tap is detected.
 	/// </summary>
@@ -80,16 +104,16 @@ public float DoubleTapZoomFactor
 	}
 
 	/// <summary>
-	/// Gets or sets the duration of the double-tap zoom animation, in milliseconds.
+	/// Gets or sets the duration of the double-tap zoom animation.
 	/// </summary>
-	/// <value>The animation duration in milliseconds. The default is <c>250</c>. A value of <c>0</c> applies the zoom instantly.</value>
+	/// <value>The animation duration. The default is <c>250 ms</c>. A value of <see cref="TimeSpan.Zero"/> applies the zoom instantly.</value>
 	/// <exception cref="ArgumentOutOfRangeException"><paramref name="value"/> is negative.</exception>
-	public int ZoomAnimationDuration
+	public TimeSpan ZoomAnimationDuration
 	{
 		get => _zoomAnimationDuration;
 		set
 		{
-			if (value < 0)
+			if (value < TimeSpan.Zero)
 				throw new ArgumentOutOfRangeException(nameof(value), value, "ZoomAnimationDuration must not be negative.");
 			_zoomAnimationDuration = value;
 		}
@@ -150,38 +174,38 @@ public float FlingMinVelocity
 	}
 
 	/// <summary>
-	/// Gets or sets the fling animation frame interval, in milliseconds.
+	/// Gets or sets the fling animation frame interval.
 	/// </summary>
 	/// <value>
-	/// The timer interval between fling animation frames in milliseconds.
-	/// The default is <c>16</c> (approximately 60 FPS). Must be positive.
+	/// The timer interval between fling animation frames.
+	/// The default is <c>16 ms</c> (approximately 60 FPS). Must be positive.
 	/// </value>
 	/// <exception cref="ArgumentOutOfRangeException"><paramref name="value"/> is zero or negative.</exception>
-	public int FlingFrameInterval
+	public TimeSpan FlingFrameInterval
 	{
 		get => _flingFrameInterval;
 		set
 		{
-			if (value <= 0)
+			if (value <= TimeSpan.Zero)
 				throw new ArgumentOutOfRangeException(nameof(value), value, "FlingFrameInterval must be positive.");
 			_flingFrameInterval = value;
 		}
 	}
 
 	/// <summary>
-	/// Gets or sets the zoom animation frame interval, in milliseconds.
+	/// Gets or sets the zoom animation frame interval.
 	/// </summary>
 	/// <value>
-	/// The timer interval between zoom animation frames in milliseconds.
-	/// The default is <c>16</c> (approximately 60 FPS). Must be positive.
+	/// The timer interval between zoom animation frames.
+	/// The default is <c>16 ms</c> (approximately 60 FPS). Must be positive.
 	/// </value>
 	/// <exception cref="ArgumentOutOfRangeException"><paramref name="value"/> is zero or negative.</exception>
-	public int ZoomAnimationInterval
+	public TimeSpan ZoomAnimationInterval
 	{
 		get => _zoomAnimationInterval;
 		set
 		{
-			if (value <= 0)
+			if (value <= TimeSpan.Zero)
 				throw new ArgumentOutOfRangeException(nameof(value), value, "ZoomAnimationInterval must be positive.");
 			_zoomAnimationInterval = value;
 		}

tests/SkiaSharp.Extended.Tests/Gestures/SKGestureDetectorTapTests.cs

@@ -118,7 +118,7 @@ public void DoubleTap_TapCountIsTwo()
 	public async Task LongTouch_RaisesLongPressDetected()
 	{
 		var engine = new SKGestureDetector();
-		engine.Options.LongPressDuration = 100; // Short duration for testing
+		engine.Options.LongPressDuration = TimeSpan.FromMilliseconds(100); // Short duration for testing
 		var longPressRaised = false;
 		engine.LongPressDetected += (s, e) => longPressRaised = true;
 
@@ -133,7 +133,7 @@ public async Task LongTouch_RaisesLongPressDetected()
 	public async Task LongPress_DoesNotRaiseTapOnRelease()
 	{
 		var engine = new SKGestureDetector();
-		engine.Options.LongPressDuration = 100;
+		engine.Options.LongPressDuration = TimeSpan.FromMilliseconds(100);
 		var tapRaised = false;
 		var longPressRaised = false;
 		engine.TapDetected += (s, e) => tapRaised = true;
@@ -152,7 +152,7 @@ public async Task LongPress_DoesNotRaiseTapOnRelease()
 	public async Task LongPressDuration_CanBeCustomized()
 	{
 		var engine = new SKGestureDetector();
-		engine.Options.LongPressDuration = 300;
+		engine.Options.LongPressDuration = TimeSpan.FromMilliseconds(300);
 		var longPressRaised = false;
 		engine.LongPressDetected += (s, e) => longPressRaised = true;
 
@@ -200,5 +200,34 @@ public void TouchHeld_WithSmallMoves_BeyondLongPressDuration_DoesNotFireTap()
 		Assert.False(tapRaised, "Touch held too long should not fire tap");
 	}
 
+	[Fact]
+	public void TapThenPinchThenTap_DoesNotFireDoubleTap()
+	{
+		// Bug fix: _tapCount was not cleared when entering Pinching state, causing
+		// a false DoubleTapDetected on the subsequent single tap.
+		var engine = CreateEngine();
+		var doubleTapRaised = false;
+		engine.DoubleTapDetected += (s, e) => doubleTapRaised = true;
+
+		// First tap
+		engine.ProcessTouchDown(1, new SKPoint(100, 100));
+		engine.ProcessTouchUp(1, new SKPoint(100, 100));
+
+		// Immediately start a pinch (within double-tap time window)
+		AdvanceTime(100); // < 300ms double-tap delay
+		engine.ProcessTouchDown(1, new SKPoint(100, 100));
+		engine.ProcessTouchDown(2, new SKPoint(200, 100));
+		engine.ProcessTouchMove(1, new SKPoint(80, 100));
+		engine.ProcessTouchMove(2, new SKPoint(220, 100));
+		engine.ProcessTouchUp(2, new SKPoint(220, 100));
+		engine.ProcessTouchUp(1, new SKPoint(80, 100));
+
+		// Third tap shortly after pinch completes (still within original 300ms window from first tap)
+		AdvanceTime(50);
+		engine.ProcessTouchDown(1, new SKPoint(100, 100));
+		engine.ProcessTouchUp(1, new SKPoint(100, 100));
+
+		Assert.False(doubleTapRaised, "DoubleTapDetected must not fire after tap → pinch → single tap sequence");
+	}
 
 }

tests/SkiaSharp.Extended.Tests/Gestures/SKGestureDetectorTests.cs

@@ -749,7 +749,7 @@ public void Options_FlingThreshold_Negative_Throws()
 	public void Options_LongPressDuration_ZeroOrNegative_Throws(int value)
 	{
 		var options = new SKGestureDetectorOptions();
-		Assert.Throws<ArgumentOutOfRangeException>(() => options.LongPressDuration = value);
+		Assert.Throws<ArgumentOutOfRangeException>(() => options.LongPressDuration = TimeSpan.FromMilliseconds(value));
 	}
 
 	[Fact]
@@ -766,14 +766,14 @@ public void Options_ValidValues_PassThrough()
 			TouchSlop = 16f,
 			DoubleTapSlop = 80f,
 			FlingThreshold = 400f,
-			LongPressDuration = 1000,
+			LongPressDuration = TimeSpan.FromSeconds(1),
 		};
 		var engine = new SKGestureDetector(options);
 
 		Assert.Equal(16f, engine.Options.TouchSlop);
 		Assert.Equal(80f, engine.Options.DoubleTapSlop);
 		Assert.Equal(400f, engine.Options.FlingThreshold);
-		Assert.Equal(1000, engine.Options.LongPressDuration);
+		Assert.Equal(TimeSpan.FromSeconds(1), engine.Options.LongPressDuration);
 	}
 
 
@@ -929,7 +929,7 @@ public void LongPressTimer_NotRestarted_OnSecondFingerDown()
 		// Regression: StartLongPressTimer() was called for every ProcessTouchDown,
 		// including the 2nd finger, resetting the long-press timer during pinch start.
 		var engine = CreateEngine();
-		engine.Options.LongPressDuration = 200; // Short for test
+		engine.Options.LongPressDuration = TimeSpan.FromMilliseconds(200); // Short for test
 
 		var longPressCount = 0;
 		engine.LongPressDetected += (s, e) => longPressCount++;

tests/SkiaSharp.Extended.Tests/Gestures/SKGestureTrackerFlingTests.cs

@@ -54,7 +54,7 @@ public void FastSwipe_FiresFlingDetected()
 	public async Task Fling_FiresFlingUpdatedEvents()
 	{
 		var tracker = CreateTracker();
-		tracker.Options.FlingFrameInterval = 16;
+		tracker.Options.FlingFrameInterval = TimeSpan.FromMilliseconds(16);
 		var flingUpdatedCount = 0;
 		tracker.FlingUpdated += (s, e) => flingUpdatedCount++;
 
@@ -70,7 +70,7 @@ public async Task Fling_FiresFlingUpdatedEvents()
 	public async Task Fling_UpdatesOffset()
 	{
 		var tracker = CreateTracker();
-		tracker.Options.FlingFrameInterval = 16;
+		tracker.Options.FlingFrameInterval = TimeSpan.FromMilliseconds(16);
 		var flingUpdatedFired = false;
 		tracker.FlingUpdated += (s, e) => flingUpdatedFired = true;
 
@@ -118,7 +118,7 @@ public async Task Fling_EventuallyCompletes()
 	{
 		// Use real TimeProvider so fling frame timing advances with wall-clock time
 		var tracker = new SKGestureTracker();
-		tracker.Options.FlingFrameInterval = 16;
+		tracker.Options.FlingFrameInterval = TimeSpan.FromMilliseconds(16);
 		tracker.Options.FlingFriction = 0.5f;
 		tracker.Options.FlingMinVelocity = 100f;
 		var flingCompleted = false;