Another refactoring: make sure input events are processed even if a w…

…idget was removed from the desktop

src/Myra/Graphics2D/UI/Desktop.Input.cs

@@ -1,6 +1,5 @@
 using Myra.Utility;
 using System;
-using System.Collections.Generic;
 using Myra.Events;
 
 #if MONOGAME || FNA
@@ -31,7 +30,7 @@ public struct MouseInfo
 		public float Wheel;
 	}
 
-	partial class Desktop
+	partial class Desktop: IInputEventsProcessor
 	{
 		private MouseInfo _lastMouseInfo;
 		private DateTime? _lastKeyDown;
@@ -40,8 +39,6 @@ partial class Desktop
 		private Point _mousePosition;
 		private Point? _touchPosition;
 		private float _mouseWheelDelta;
-		private readonly List<InputEventType> _scheduledInputEvents = new List<InputEventType>();
-		private readonly List<InputEventType> _scheduledInputEventsCopy = new List<InputEventType>();
 
 		public Point PreviousMousePosition { get; private set; }
 		public Point? PreviousTouchPosition { get; private set; }
@@ -57,7 +54,7 @@ private set
 				}
 
 				_mousePosition = value;
-				_scheduledInputEvents.Add(InputEventType.MouseMoved);
+				InputEventsManager.QueueMouseMoved(this);
 			}
 		}
 
@@ -77,16 +74,16 @@ private set
 
 				if (value != null && oldValue == null)
 				{
-					_scheduledInputEvents.Add(InputEventType.TouchDown);
+					InputEventsManager.QueueTouchDown(this);
 				}
 				else if (value == null && oldValue != null)
 				{
-					_scheduledInputEvents.Add(InputEventType.TouchUp);
+					InputEventsManager.QueueTouchUp(this);
 				}
 				else if (value != null && oldValue != null &&
 					value.Value != oldValue.Value)
 				{
-					_scheduledInputEvents.Add(InputEventType.TouchMoved);
+					InputEventsManager.QueueTouchMoved(this);
 				}
 			}
 		}
@@ -103,7 +100,7 @@ public float MouseWheelDelta
 
 				if (!value.IsZero())
 				{
-					_scheduledInputEvents.Add(InputEventType.MouseWheel);
+					InputEventsManager.QueueMouseWheel(this);
 				}
 			}
 		}
@@ -283,49 +280,37 @@ public void UpdateInput()
 			}
 		}
 
-		public void ProcessInputEvents()
+		void IInputEventsProcessor.ProcessEvent(InputEventType eventType)
 		{
-			if (_scheduledInputEvents.Count == 0)
+			switch (eventType)
 			{
-				return;
-			}
-
-			_scheduledInputEventsCopy.Clear();
-			_scheduledInputEventsCopy.AddRange(_scheduledInputEvents);
-			_scheduledInputEvents.Clear();
-
-			foreach (var inputEventType in _scheduledInputEventsCopy)
-			{
-				switch (inputEventType)
-				{
-					case InputEventType.MouseLeft:
-						break;
-					case InputEventType.MouseEntered:
-						break;
-					case InputEventType.MouseMoved:
-						MouseMoved.Invoke(this);
-						break;
-					case InputEventType.MouseWheel:
-						MouseWheelChanged.Invoke(this, MouseWheelDelta);
-						break;
-					case InputEventType.TouchLeft:
-						break;
-					case InputEventType.TouchEntered:
-						break;
-					case InputEventType.TouchMoved:
-						TouchMoved.Invoke(this);
-						break;
-					case InputEventType.TouchDown:
-						InputOnTouchDown();
-						TouchDown.Invoke(this);
-						break;
-					case InputEventType.TouchUp:
-						TouchUp.Invoke(this);
-						break;
-					case InputEventType.TouchDoubleClick:
-						TouchDoubleClick.Invoke(this);
-						break;
-				}
+				case InputEventType.MouseLeft:
+					break;
+				case InputEventType.MouseEntered:
+					break;
+				case InputEventType.MouseMoved:
+					MouseMoved.Invoke(this);
+					break;
+				case InputEventType.MouseWheel:
+					MouseWheelChanged.Invoke(this, MouseWheelDelta);
+					break;
+				case InputEventType.TouchLeft:
+					break;
+				case InputEventType.TouchEntered:
+					break;
+				case InputEventType.TouchMoved:
+					TouchMoved.Invoke(this);
+					break;
+				case InputEventType.TouchDown:
+					InputOnTouchDown();
+					TouchDown.Invoke(this);
+					break;
+				case InputEventType.TouchUp:
+					TouchUp.Invoke(this);
+					break;
+				case InputEventType.TouchDoubleClick:
+					TouchDoubleClick.Invoke(this);
+					break;
 			}
 		}
 	}

src/Myra/Graphics2D/UI/Desktop.cs

@@ -527,18 +527,11 @@ public void Render()
 			// So scheduling it here
 			if (_inputContext.MouseWheelWidget != null)
 			{
-				_inputContext.MouseWheelWidget.ScheduleInputEvent(InputEventType.MouseWheel);
+				InputEventsManager.QueueMouseWheel(_inputContext.MouseWheelWidget);
 			}
 
 			// Second input run: process input events
-			ProcessInputEvents();
-
-			childrenCopy = ChildrenCopy;
-			for (var i = childrenCopy.Count - 1; i >= 0; --i)
-			{
-				var widget = childrenCopy[i];
-				widget.ProcessInputEvents();
-			}
+			InputEventsManager.ProcessEvents();
 
 			// Do another layout run, since an input event could cause the layout change
 			UpdateLayout();

src/Myra/Graphics2D/UI/InputEventsManager.cs

@@ -0,0 +1,112 @@
+using System.Collections.Generic;
+
+#if MONOGAME || FNA
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Input;
+#elif STRIDE
+using Stride.Core.Mathematics;
+using Stride.Input;
+#else
+using System.Numerics;
+using System.Drawing;
+using Myra.Platform;
+#endif
+
+namespace Myra.Graphics2D.UI
+{
+	internal enum InputEventType
+	{
+		MouseLeft,
+		MouseEntered,
+		MouseMoved,
+		MouseWheel,
+		TouchLeft,
+		TouchEntered,
+		TouchMoved,
+		TouchDown,
+		TouchUp,
+		TouchDoubleClick
+	}
+
+	internal interface IInputEventsProcessor
+	{
+		void ProcessEvent(InputEventType eventType);
+	}
+
+	internal static class InputEventsManager
+	{
+		private struct InputEvent
+		{
+			public IInputEventsProcessor Processor;
+			public InputEventType Type;
+
+			public InputEvent(IInputEventsProcessor processor, InputEventType type)
+			{
+				Processor = processor;
+				Type = type;
+			}
+		}
+
+		private static readonly Queue<InputEvent> _events = new Queue<InputEvent>();
+
+		public static void QueueMouseLeft(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.MouseLeft));
+		}
+
+		public static void QueueMouseEntered(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.MouseEntered));
+		}
+
+		public static void QueueMouseMoved(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.MouseMoved));
+		}
+
+		public static void QueueMouseWheel(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.MouseWheel));
+		}
+
+		public static void QueueTouchLeft(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.TouchLeft));
+		}
+
+		public static void QueueTouchEntered(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.TouchEntered));
+		}
+
+		public static void QueueTouchMoved(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.TouchMoved));
+		}
+
+		public static void QueueTouchDown(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.TouchDown));
+		}
+
+		public static void QueueTouchUp(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.TouchUp));
+		}
+
+		public static void QueueTouchDoubleClick(IInputEventsProcessor processor)
+		{
+			_events.Enqueue(new InputEvent(processor, InputEventType.TouchDoubleClick));
+		}
+
+		public static void ProcessEvents()
+		{
+			while(_events.Count > 0)
+			{
+				var ev = _events.Dequeue();
+
+				ev.Processor.ProcessEvent(ev.Type);
+			}
+		}
+	}
+}