From 1cc29c7e8d24c0d326c741f0488c92b95ac6b718 Mon Sep 17 00:00:00 2001
From: Emmanuel Hansen <emmausssss@gmail.com>
Date: Fri, 20 Jan 2023 09:35:37 +0000
Subject: [PATCH] set pull and pich gestures to handled when handled by handler

---
 samples/ControlCatalog/Pages/GesturePage.cs   | 35 ++++++++++++-------
 .../PinchGestureRecognizer.cs                 |  5 ++-
 .../PullGestureRecognizer.cs                  |  6 +++-
 3 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/samples/ControlCatalog/Pages/GesturePage.cs b/samples/ControlCatalog/Pages/GesturePage.cs
index ee10f21317..0bb8f38219 100644
--- a/samples/ControlCatalog/Pages/GesturePage.cs
+++ b/samples/ControlCatalog/Pages/GesturePage.cs
@@ -6,6 +6,7 @@ using Avalonia.Input;
 using Avalonia.LogicalTree;
 using Avalonia.Markup.Xaml;
 using Avalonia.Rendering.Composition;
+using Avalonia.Utilities;
 
 namespace ControlCatalog.Pages
 {
@@ -53,6 +54,7 @@ namespace ControlCatalog.Pages
                 {
                     _currentScale = 1;
                     compositionVisual.Scale = new Vector3(1,1,1);
+                    compositionVisual.Offset = default;
                     image.InvalidateMeasure();
                 }
             };
@@ -100,13 +102,19 @@ namespace ControlCatalog.Pages
             {
                 InitComposition(control!);
 
-                isZooming = true;
-
                 if(compositionVisual != null)
                 {
                     var scale = _currentScale * (float)e.Scale;
 
+                    if (scale <= 1)
+                    {
+                        scale = 1;
+                        compositionVisual.Offset = default;
+                    }
+
                     compositionVisual.Scale = new(scale, scale, 1);
+
+                    e.Handled = true;
                 }
             });
 
@@ -114,8 +122,6 @@ namespace ControlCatalog.Pages
             {
                 InitComposition(control!);
 
-                isZooming = false;
-
                 if (compositionVisual != null)
                 {
                     _currentScale = compositionVisual.Scale.X;
@@ -126,11 +132,19 @@ namespace ControlCatalog.Pages
             {
                 InitComposition(control!);
 
-                if (compositionVisual != null && !isZooming)
+                if (compositionVisual != null && _currentScale != 1)
                 {
-                    currentOffset -= new Vector3((float)e.Delta.X, (float)e.Delta.Y, 0);
+                    currentOffset += new Vector3((float)e.Delta.X, (float)e.Delta.Y, 0);
+
+                    var currentSize = control.Bounds.Size * _currentScale;
+
+                    currentOffset = new Vector3((float)MathUtilities.Clamp(currentOffset.X, 0, currentSize.Width - control.Bounds.Width),
+                        (float)MathUtilities.Clamp(currentOffset.Y, 0, currentSize.Height - control.Bounds.Height),
+                        0);
 
-                    compositionVisual.Offset = currentOffset;
+                    compositionVisual.Offset = currentOffset * -1;
+
+                    e.Handled = true;
                 }
             });
         }
@@ -173,6 +187,8 @@ namespace ControlCatalog.Pages
                 if (ballCompositionVisual != null)
                 {
                     ballCompositionVisual.Offset = defaultOffset + new System.Numerics.Vector3((float)e.Delta.X * 0.4f, (float)e.Delta.Y * 0.4f, 0) * (inverse ? -1 : 1);
+
+                    e.Handled = true;
                 }
             });
 
@@ -187,11 +203,6 @@ namespace ControlCatalog.Pages
 
             void InitComposition(Control control)
             {
-                if (ballCompositionVisual != null)
-                {
-                    return;
-                }
-
                 ballCompositionVisual = ElementComposition.GetElementVisual(ball);
 
                 if (ballCompositionVisual != null)
diff --git a/src/Avalonia.Base/Input/GestureRecognizers/PinchGestureRecognizer.cs b/src/Avalonia.Base/Input/GestureRecognizers/PinchGestureRecognizer.cs
index eea7c3b7d1..3b83d0cb87 100644
--- a/src/Avalonia.Base/Input/GestureRecognizers/PinchGestureRecognizer.cs
+++ b/src/Avalonia.Base/Input/GestureRecognizers/PinchGestureRecognizer.cs
@@ -57,7 +57,10 @@ namespace Avalonia.Input
 
                     var scale = distance / _initialDistance;
 
-                    _target?.RaiseEvent(new PinchEventArgs(scale, _origin));
+                    var pinchEventArgs = new PinchEventArgs(scale, _origin);
+                    _target?.RaiseEvent(pinchEventArgs);
+
+                    e.Handled = pinchEventArgs.Handled;
                 }
             }
         }
diff --git a/src/Avalonia.Base/Input/GestureRecognizers/PullGestureRecognizer.cs b/src/Avalonia.Base/Input/GestureRecognizers/PullGestureRecognizer.cs
index 23bab13fc8..991694cc60 100644
--- a/src/Avalonia.Base/Input/GestureRecognizers/PullGestureRecognizer.cs
+++ b/src/Avalonia.Base/Input/GestureRecognizers/PullGestureRecognizer.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using Avalonia.Input.GestureRecognizers;
 
 namespace Avalonia.Input
@@ -88,7 +89,10 @@ namespace Avalonia.Input
                 }
 
                 _pullInProgress = true;
-                _target?.RaiseEvent(new PullGestureEventArgs(_gestureId, delta, PullDirection));
+                var pullEventArgs = new PullGestureEventArgs(_gestureId, delta, PullDirection);
+                _target?.RaiseEvent(pullEventArgs);
+
+                e.Handled = pullEventArgs.Handled;
             }
         }