open-maui/OpenMaui
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Gesture support

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This commit is contained in:
David H. Friedel Jr.
2026-01-17 02:48:59 +00:00
parent 5a915ca06a
commit 5443c7c22a
5 changed files with 333 additions and 9 deletions
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284
Handlers/GestureManager.cs
View File

@@ -9,7 +9,7 @@ namespace Microsoft.Maui.Platform.Linux.Handlers;
/// <summary>
/// Manages gesture recognition and processing for MAUI views on Linux.
/// Handles tap, pan, swipe, and pointer gestures.
/// Handles tap, pan, swipe, pinch, and pointer gestures.
/// </summary>
public static class GestureManager
{
@@ -22,6 +22,8 @@ public static class GestureManager
public DateTime StartTime { get; set; }
public bool IsPanning { get; set; }
public bool IsPressed { get; set; }
public bool IsPinching { get; set; }
public double PinchScale { get; set; } = 1.0;
}
private enum PointerEventType
@@ -34,6 +36,7 @@ public static class GestureManager
}
private static MethodInfo? _sendTappedMethod;
private static MethodInfo? _sendPinchMethod;
private static readonly Dictionary<View, (DateTime lastTap, int tapCount)> _tapTracking = new Dictionary<View, (DateTime, int)>();
private static readonly Dictionary<View, GestureTrackingState> _gestureState = new Dictionary<View, GestureTrackingState>();
@@ -41,6 +44,7 @@ public static class GestureManager
private const double SwipeMaxTime = 500.0;
private const double SwipeDirectionThreshold = 0.5;
private const double PanMinDistance = 10.0;
private const double PinchScrollScale = 0.1; // Scale factor per scroll unit
/// <summary>
/// Processes a tap gesture on the specified view.
@@ -504,6 +508,142 @@ public static class GestureManager
return null!;
}
/// <summary>
/// Processes a scroll event that may be a pinch gesture (Ctrl+Scroll).
/// Returns true if the scroll was consumed as a pinch gesture.
/// </summary>
public static bool ProcessScrollAsPinch(View? view, double x, double y, double deltaY, bool isCtrlPressed)
{
if (view == null || !isCtrlPressed)
{
return false;
}
// Check if view has a pinch gesture recognizer
if (!HasPinchGestureRecognizer(view))
{
return false;
}
// Get or create gesture state
if (!_gestureState.TryGetValue(view, out var state))
{
state = new GestureTrackingState
{
StartX = x,
StartY = y,
CurrentX = x,
CurrentY = y,
StartTime = DateTime.UtcNow,
PinchScale = 1.0
};
_gestureState[view] = state;
}
// Calculate new scale based on scroll delta
double scaleDelta = 1.0 + (deltaY * PinchScrollScale);
state.PinchScale *= scaleDelta;
// Clamp scale to reasonable bounds
state.PinchScale = Math.Clamp(state.PinchScale, 0.1, 10.0);
GestureStatus status;
if (!state.IsPinching)
{
state.IsPinching = true;
status = GestureStatus.Started;
}
else
{
status = GestureStatus.Running;
}
ProcessPinchGesture(view, state.PinchScale, x, y, status);
return true;
}
/// <summary>
/// Ends an ongoing pinch gesture.
/// </summary>
public static void EndPinchGesture(View? view)
{
if (view == null) return;
if (_gestureState.TryGetValue(view, out var state) && state.IsPinching)
{
ProcessPinchGesture(view, state.PinchScale, state.CurrentX, state.CurrentY, GestureStatus.Completed);
state.IsPinching = false;
state.PinchScale = 1.0;
}
}
private static void ProcessPinchGesture(View view, double scale, double originX, double originY, GestureStatus status)
{
var recognizers = view.GestureRecognizers;
if (recognizers == null)
{
return;
}
foreach (var item in recognizers)
{
var pinchRecognizer = item as PinchGestureRecognizer;
if (pinchRecognizer == null)
{
continue;
}
Console.WriteLine($"[GestureManager] Pinch gesture: status={status}, scale={scale:F2}, origin=({originX:F0},{originY:F0})");
try
{
// Cache the method lookup
if (_sendPinchMethod == null)
{
_sendPinchMethod = typeof(PinchGestureRecognizer).GetMethod("SendPinch",
BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
}
if (_sendPinchMethod != null)
{
// SendPinch(IView sender, double scale, Point scaleOrigin, GestureStatus status)
var scaleOrigin = new Point(originX / view.Width, originY / view.Height);
_sendPinchMethod.Invoke(pinchRecognizer, new object[]
{
view,
scale,
scaleOrigin,
status
});
Console.WriteLine("[GestureManager] SendPinch invoked successfully");
}
}
catch (Exception ex)
{
Console.WriteLine($"[GestureManager] SendPinch failed: {ex.Message}");
}
}
}
/// <summary>
/// Checks if the view has a pinch gesture recognizer.
/// </summary>
public static bool HasPinchGestureRecognizer(View? view)
{
if (view?.GestureRecognizers == null)
{
return false;
}
foreach (var recognizer in view.GestureRecognizers)
{
if (recognizer is PinchGestureRecognizer)
{
return true;
}
}
return false;
}
/// <summary>
/// Checks if the view has a swipe gesture recognizer.
/// </summary>
@@ -560,4 +700,146 @@ public static class GestureManager
}
return false;
}
/// <summary>
/// Checks if the view has a drag gesture recognizer.
/// </summary>
public static bool HasDragGestureRecognizer(View? view)
{
if (view?.GestureRecognizers == null)
{
return false;
}
foreach (var recognizer in view.GestureRecognizers)
{
if (recognizer is DragGestureRecognizer)
{
return true;
}
}
return false;
}
/// <summary>
/// Checks if the view has a drop gesture recognizer.
/// </summary>
public static bool HasDropGestureRecognizer(View? view)
{
if (view?.GestureRecognizers == null)
{
return false;
}
foreach (var recognizer in view.GestureRecognizers)
{
if (recognizer is DropGestureRecognizer)
{
return true;
}
}
return false;
}
/// <summary>
/// Initiates a drag operation from the specified view.
/// </summary>
public static void StartDrag(View? view, double x, double y)
{
if (view == null) return;
var recognizers = view.GestureRecognizers;
if (recognizers == null) return;
foreach (var item in recognizers)
{
var dragRecognizer = item as DragGestureRecognizer;
if (dragRecognizer == null) continue;
Console.WriteLine($"[GestureManager] Starting drag from {view.GetType().Name}");
try
{
// Create DragStartingEventArgs and invoke SendDragStarting
var method = typeof(DragGestureRecognizer).GetMethod("SendDragStarting",
BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
if (method != null)
{
method.Invoke(dragRecognizer, new object[] { view });
Console.WriteLine("[GestureManager] SendDragStarting invoked successfully");
}
}
catch (Exception ex)
{
Console.WriteLine($"[GestureManager] SendDragStarting failed: {ex.Message}");
}
}
}
/// <summary>
/// Processes a drag enter event on the specified view.
/// </summary>
public static void ProcessDragEnter(View? view, double x, double y, object? data)
{
if (view == null) return;
var recognizers = view.GestureRecognizers;
if (recognizers == null) return;
foreach (var item in recognizers)
{
var dropRecognizer = item as DropGestureRecognizer;
if (dropRecognizer == null) continue;
Console.WriteLine($"[GestureManager] Drag enter on {view.GetType().Name}");
try
{
var method = typeof(DropGestureRecognizer).GetMethod("SendDragOver",
BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
if (method != null)
{
method.Invoke(dropRecognizer, new object[] { view });
}
}
catch (Exception ex)
{
Console.WriteLine($"[GestureManager] SendDragOver failed: {ex.Message}");
}
}
}
/// <summary>
/// Processes a drop event on the specified view.
/// </summary>
public static void ProcessDrop(View? view, double x, double y, object? data)
{
if (view == null) return;
var recognizers = view.GestureRecognizers;
if (recognizers == null) return;
foreach (var item in recognizers)
{
var dropRecognizer = item as DropGestureRecognizer;
if (dropRecognizer == null) continue;
Console.WriteLine($"[GestureManager] Drop on {view.GetType().Name}");
try
{
var method = typeof(DropGestureRecognizer).GetMethod("SendDrop",
BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
if (method != null)
{
method.Invoke(dropRecognizer, new object[] { view });
}
}
catch (Exception ex)
{
Console.WriteLine($"[GestureManager] SendDrop failed: {ex.Message}");
}
}
}
}

1
Hosting/LinuxMauiAppBuilderExtensions.cs
View File

@@ -72,6 +72,7 @@ public static class LinuxMauiAppBuilderExtensions
builder.Services.TryAddSingleton<NotificationService>();
builder.Services.TryAddSingleton<SystemTrayService>();
builder.Services.TryAddSingleton(_ => MonitorService.Instance);
builder.Services.TryAddSingleton<DragDropService>();
// Register GTK host service
builder.Services.TryAddSingleton(_ => GtkHostService.Instance);

38
LinuxApplication.cs
View File

@@ -929,16 +929,31 @@ public class LinuxApplication : IDisposable
}
}
private void OnGtkScrolled(object? sender, (double X, double Y, double DeltaX, double DeltaY) e)
private void OnGtkScrolled(object? sender, (double X, double Y, double DeltaX, double DeltaY, uint State) e)
{
if (_rootView == null) return;
// Convert GDK state to KeyModifiers
var modifiers = ConvertGdkStateToModifiers(e.State);
bool isCtrlPressed = (modifiers & KeyModifiers.Control) != 0;
var hitView = _rootView.HitTest((float)e.X, (float)e.Y);
// Check for pinch gesture (Ctrl+Scroll) first
if (isCtrlPressed && hitView?.MauiView != null)
{
if (Handlers.GestureManager.ProcessScrollAsPinch(hitView.MauiView, e.X, e.Y, e.DeltaY, true))
{
_gtkWindow?.RequestRedraw();
return;
}
}
while (hitView != null)
{
if (hitView is SkiaScrollView scrollView)
{
var args = new ScrollEventArgs((float)e.X, (float)e.Y, (float)e.DeltaX, (float)e.DeltaY);
var args = new ScrollEventArgs((float)e.X, (float)e.Y, (float)e.DeltaX, (float)e.DeltaY, modifiers);
scrollView.OnScroll(args);
_gtkWindow?.RequestRedraw();
break;
@@ -947,6 +962,25 @@ public class LinuxApplication : IDisposable
}
}
private static KeyModifiers ConvertGdkStateToModifiers(uint state)
{
var modifiers = KeyModifiers.None;
// GDK modifier masks
const uint GDK_SHIFT_MASK = 1 << 0;
const uint GDK_CONTROL_MASK = 1 << 2;
const uint GDK_MOD1_MASK = 1 << 3; // Alt
const uint GDK_SUPER_MASK = 1 << 26;
const uint GDK_LOCK_MASK = 1 << 1; // Caps Lock
if ((state & GDK_SHIFT_MASK) != 0) modifiers |= KeyModifiers.Shift;
if ((state & GDK_CONTROL_MASK) != 0) modifiers |= KeyModifiers.Control;
if ((state & GDK_MOD1_MASK) != 0) modifiers |= KeyModifiers.Alt;
if ((state & GDK_SUPER_MASK) != 0) modifiers |= KeyModifiers.Super;
if ((state & GDK_LOCK_MASK) != 0) modifiers |= KeyModifiers.CapsLock;
return modifiers;
}
private void OnGtkTextInput(object? sender, string text)
{
if (_focusedView != null)

10
Rendering/GtkSkiaSurfaceWidget.cs
View File

@@ -113,7 +113,7 @@ public sealed class GtkSkiaSurfaceWidget : IDisposable
public event EventHandler<(double X, double Y)>? PointerMoved;
public event EventHandler<(uint KeyVal, uint KeyCode, uint State)>? KeyPressed;
public event EventHandler<(uint KeyVal, uint KeyCode, uint State)>? KeyReleased;
public event EventHandler<(double X, double Y, double DeltaX, double DeltaY)>? Scrolled;
public event EventHandler<(double X, double Y, double DeltaX, double DeltaY, uint State)>? Scrolled;
public event EventHandler<string>? TextInput;
public GtkSkiaSurfaceWidget(int width, int height)
@@ -314,8 +314,8 @@ public sealed class GtkSkiaSurfaceWidget : IDisposable
private bool OnScroll(IntPtr widget, IntPtr eventData, IntPtr userData)
{
var (x, y, deltaX, deltaY) = ParseScrollEvent(eventData);
Scrolled?.Invoke(this, (x, y, deltaX, deltaY));
var (x, y, deltaX, deltaY, state) = ParseScrollEvent(eventData);
Scrolled?.Invoke(this, (x, y, deltaX, deltaY, state));
return true;
}
@@ -337,7 +337,7 @@ public sealed class GtkSkiaSurfaceWidget : IDisposable
return (evt.keyval, evt.hardware_keycode, evt.state);
}
private static (double x, double y, double deltaX, double deltaY) ParseScrollEvent(IntPtr eventData)
private static (double x, double y, double deltaX, double deltaY, uint state) ParseScrollEvent(IntPtr eventData)
{
var evt = Marshal.PtrToStructure<GdkEventScroll>(eventData);
double deltaX = 0.0;
@@ -366,7 +366,7 @@ public sealed class GtkSkiaSurfaceWidget : IDisposable
break;
}
}
return (evt.x, evt.y, deltaX, deltaY);
return (evt.x, evt.y, deltaX, deltaY, evt.state);
}
public void GrabFocus()

9
Views/SkiaView.cs
View File

@@ -1738,14 +1738,21 @@ public class ScrollEventArgs : EventArgs
public float Y { get; }
public float DeltaX { get; }
public float DeltaY { get; }
public KeyModifiers Modifiers { get; }
public bool Handled { get; set; }
public ScrollEventArgs(float x, float y, float deltaX, float deltaY)
/// <summary>
/// Gets whether the Control key is pressed during this scroll event.
/// </summary>
public bool IsControlPressed => (Modifiers & KeyModifiers.Control) != 0;
public ScrollEventArgs(float x, float y, float deltaX, float deltaY, KeyModifiers modifiers = KeyModifiers.None)
{
X = x;
Y = y;
DeltaX = deltaX;
DeltaY = deltaY;
Modifiers = modifiers;
}
}