Update PlatformTouchEffect.cs

Author: RobertStefancic

Source/OxyPlot.Maui.Skia/Platforms/iOS/Effects/PlatformTouchEffect.cs

@@ -8,24 +8,18 @@ namespace OxyPlot.Maui.Skia.ios.Effects;
 
 public class PlatformTouchEffect : PlatformEffect
 {
- UIView view;
- TouchRecognizer touchRecognizer;
+ private UIView view;
+ private TouchRecognizer touchRecognizer;
 
  protected override void OnAttached()
  {
- // Get the iOS UIView corresponding to the Element that the effect is attached to
  view = Control ?? Container;
 
- // Uncomment this line if the UIView does not have touch enabled by default
- //view.UserInteractionEnabled = true;
-
- // Get access to the TouchEffect class in the .NET Standard library
  var touchEffect = Element.Effects.OfType<MyTouchEffect>().FirstOrDefault();
 
  if (touchEffect != null && view != null)
  {
- // Create a TouchRecognizer for this UIView
- touchRecognizer = new TouchRecognizer(Element, view, touchEffect);
+ touchRecognizer = new TouchRecognizer(Element, touchEffect);
  view.AddGestureRecognizer(touchRecognizer);
  }
  }
@@ -34,140 +28,71 @@ protected override void OnDetached()
  {
  if (touchRecognizer != null)
  {
- // Clean up the TouchRecognizer object
  touchRecognizer.Detach();
-
- // Remove the TouchRecognizer from the UIView
  view.RemoveGestureRecognizer(touchRecognizer);
  }
  }
 }
 
-class TouchRecognizer : UIGestureRecognizer
+internal class TouchRecognizer : UIGestureRecognizer
 {
- Microsoft.Maui.Controls.Element element; // Forms element for firing events
- UIView view; // iOS UIView 
- MyTouchEffect touchPlatformEffect;
-
- static Dictionary<UIView, TouchRecognizer> viewDictionary = new();
+ private readonly Microsoft.Maui.Controls.Element element;
+ private readonly MyTouchEffect touchEffect;
+ private uint activeTouchesCount = 0;
 
- static Dictionary<long, TouchRecognizer> idToTouchDictionary = new();
-
- public TouchRecognizer(Microsoft.Maui.Controls.Element element, UIView view, MyTouchEffect touchPlatformEffect)
+ public TouchRecognizer(Microsoft.Maui.Controls.Element element, MyTouchEffect touchEffect)
  {
  this.element = element;
- this.view = view;
- this.touchPlatformEffect = touchPlatformEffect;
+ this.touchEffect = touchEffect;
 
- viewDictionary.Add(view, this);
+ ShouldRecognizeSimultaneously = new UIGesturesProbe((_, _) => true);
  }
 
  public void Detach()
  {
- viewDictionary.Remove(view);
+ ShouldRecognizeSimultaneously = null;
  }
 
- // touches = touches of interest; evt = all touches of type UITouch
  public override void TouchesBegan(NSSet touches, UIEvent evt)
  {
  base.TouchesBegan(touches, evt);
-
- foreach (UITouch touch in touches.Cast<UITouch>())
- {
- long id = ((IntPtr)touch.Handle).ToInt64();
- FireEvent(this, id, TouchActionType.Pressed, touch, true);
-
- if (!idToTouchDictionary.ContainsKey(id))
- {
- idToTouchDictionary.Add(id, this);
- }
- }
+ activeTouchesCount += touches.Count.ToUInt32();
+ FireEvent(touches, TouchActionType.Pressed, true);
  }
 
  public override void TouchesMoved(NSSet touches, UIEvent evt)
  {
  base.TouchesMoved(touches, evt);
 
- foreach (UITouch touch in touches.Cast<UITouch>())
+ if (activeTouchesCount == touches.Count.ToUInt32())
  {
- long id = ((IntPtr)touch.Handle).ToInt64();
- CheckForBoundaryHop(touch);
- if (idToTouchDictionary[id] != null)
- {
- FireEvent(idToTouchDictionary[id], id, TouchActionType.Moved, touch, true);
- }
+ FireEvent(touches, TouchActionType.Moved, true);
  }
  }
 
  public override void TouchesEnded(NSSet touches, UIEvent evt)
  {
  base.TouchesEnded(touches, evt);
-
- foreach (UITouch touch in touches.Cast<UITouch>())
- {
- long id = ((IntPtr)touch.Handle).ToInt64();
- CheckForBoundaryHop(touch);
- if (idToTouchDictionary[id] != null)
- {
- FireEvent(idToTouchDictionary[id], id, TouchActionType.Released, touch, false);
- }
-
- idToTouchDictionary.Remove(id);
- }
+ activeTouchesCount -= touches.Count.ToUInt32();
+ FireEvent(touches, TouchActionType.Released, false);
  }
 
  public override void TouchesCancelled(NSSet touches, UIEvent evt)
  {
  base.TouchesCancelled(touches, evt);
-
- foreach (UITouch touch in touches.Cast<UITouch>())
- {
- long id = ((IntPtr)touch.Handle).ToInt64();
- idToTouchDictionary.Remove(id);
- }
  }
 
- void CheckForBoundaryHop(UITouch touch)
+ private void FireEvent(NSSet touches, TouchActionType actionType, bool isInContact)
  {
- long id = ((IntPtr)touch.Handle).ToInt64();
-
- // TODO: Might require converting to a List for multiple hits
- TouchRecognizer recognizerHit = null;
+ UITouch[] uiTouches = touches.Cast<UITouch>().ToArray();
+ long id = ((IntPtr)uiTouches.First().Handle).ToInt64();
+ Point[] points = new Point[uiTouches.Length];
 
- foreach (UIView view in viewDictionary.Keys)
- {
- CGPoint location = touch.LocationInView(view);
-
- if (new CGRect(new CGPoint(), view.Frame.Size).Contains(location))
- {
- recognizerHit = viewDictionary[view];
- }
- }
- if (recognizerHit != idToTouchDictionary[id])
+ for (int i = 0; i < uiTouches.Length; i++)
  {
- if (idToTouchDictionary[id] != null)
- {
- FireEvent(idToTouchDictionary[id], id, TouchActionType.Pressed, touch, true);
- }
- if (recognizerHit != null)
- {
- FireEvent(recognizerHit, id, TouchActionType.Released, touch, true);
- }
- idToTouchDictionary[id] = recognizerHit;
+ CGPoint cgPoint = uiTouches[i].LocationInView(View);
+ points[i] = new(cgPoint.X, cgPoint.Y);
  }
+ touchEffect.OnTouchAction(element, new(id, actionType, points, isInContact));
  }
-
- void FireEvent(TouchRecognizer recognizer, long id, TouchActionType actionType, UITouch touch, bool isInContact)
- {
- // Convert touch location to Maui Point value
- CGPoint cgPoint = touch.LocationInView(recognizer.View);
- Point xfPoint = new Point(cgPoint.X, cgPoint.Y);
-
- // Get the method to call for firing events
- var onTouchAction = recognizer.touchPlatformEffect.OnTouchAction;
-
- // Call that method
- onTouchAction(recognizer.element,
- new TouchActionEventArgs(id, actionType, new[] { xfPoint }, isInContact));
- }
-}
+}