Merge pull request #11051 from AvaloniaUI/fixes/11015-slider-thumb-not-moving

Fix slider thumb not moving

samples/IntegrationTestApp/MainWindow.axaml

@@ -170,10 +170,21 @@
           </StackPanel>
         </Grid>
       </TabItem>
-      <TabItem Header="SliderTab">
-          <Slider VerticalAlignment="Top" Name="Slider" Value="30"/>
+      
+      <TabItem Header="Slider">
+          <DockPanel>
+            <DockPanel DockPanel.Dock="Top">
+              <TextBox Name="HorizontalSliderValue"
+                       DockPanel.Dock="Right"
+                       Text="{Binding #HorizontalSlider.Value, Mode=OneWay, StringFormat=\{0:0\}}"
+                       VerticalAlignment="Top"/>
+              <Slider Name="HorizontalSlider" Value="50"/>
+            </DockPanel>
+            <Button Name="ResetSliders">Reset</Button>
+          </DockPanel>
       </TabItem>
-      <TabItem Header="ScrollBarTab">
+      
+      <TabItem Header="ScrollBar">
         <ScrollBar Name="MyScrollBar" Orientation="Horizontal" AllowAutoHide="False" Width="200" Height="30" Value="20"/>
       </TabItem>
     </TabControl>

samples/IntegrationTestApp/MainWindow.axaml.cs

@@ -270,6 +270,8 @@ namespace IntegrationTestApp
                 this.Get<ListBox>("BasicListBox").SelectedIndex = -1;
             if (source?.Name == "MenuClickedMenuItemReset")
                 this.Get<TextBlock>("ClickedMenuItem").Text = "None";
+            if (source?.Name == "ResetSliders")
+                this.Get<Slider>("HorizontalSlider").Value = 50;
             if (source?.Name == "ShowTransparentWindow")
                 ShowTransparentWindow();
             if (source?.Name == "ShowTransparentPopup")

src/Avalonia.Base/Layout/LayoutManager.cs

@@ -2,6 +2,7 @@ using System;
 using System.Buffers;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using Avalonia.Logging;
 using Avalonia.Rendering;
 using Avalonia.Threading;
@@ -64,7 +65,6 @@ namespace Avalonia.Layout
             }
 
             _toMeasure.Enqueue(control);
-            _toArrange.Enqueue(control);
             QueueLayoutPass();
         }
 
@@ -297,6 +297,8 @@ namespace Avalonia.Layout
                 {
                     control.Measure(control.PreviousMeasure.Value);
                 }
+
+                _toArrange.Enqueue(control);
             }
 
             return true;
@@ -313,7 +315,10 @@ namespace Avalonia.Layout
                     return false;
             }
 
-            if (control.IsMeasureValid && !control.IsArrangeValid)
+            if (!control.IsMeasureValid)
+                return false;
+
+            if (!control.IsArrangeValid)
             {
                 if (control is IEmbeddedLayoutRoot embeddedRoot)
                     control.Arrange(new Rect(embeddedRoot.AllocatedSize));

src/Avalonia.Controls/Automation/Peers/ThumbAutomationPeer.cs

@@ -0,0 +1,12 @@
+using Avalonia.Automation.Peers;
+using Avalonia.Controls.Primitives;
+
+namespace Avalonia.Controls.Automation.Peers
+{
+    public class ThumbAutomationPeer : ControlAutomationPeer
+    {
+        public ThumbAutomationPeer(Thumb owner) : base(owner) { }
+        protected override AutomationControlType GetAutomationControlTypeCore() => AutomationControlType.Thumb;
+        protected override bool IsContentElementCore() => false;
+    }
+}

src/Avalonia.Controls/Primitives/Thumb.cs

@@ -1,4 +1,6 @@
 using System;
+using Avalonia.Automation.Peers;
+using Avalonia.Controls.Automation.Peers;
 using Avalonia.Controls.Metadata;
 using Avalonia.Input;
 using Avalonia.Interactivity;
@@ -45,6 +47,8 @@ namespace Avalonia.Controls.Primitives
             remove { RemoveHandler(DragCompletedEvent, value); }
         }
 
+        protected override AutomationPeer OnCreateAutomationPeer() => new ThumbAutomationPeer(this);
+
         protected virtual void OnDragStarted(VectorEventArgs e)
         {
         }

tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs

@@ -457,5 +457,39 @@ namespace Avalonia.Base.UnitTests.Layout
             
             Assert.Equal(1, layoutCount);
         }
+
+        [Fact]
+        public void Child_Can_Invalidate_Parent_Measure_During_Arrange()
+        {
+            // Issue #11015.
+            //
+            // - Child invalidates parent measure in arrange pass
+            // - Parent is added to measure & arrange queues
+            // - Arrange pass dequeues parent
+            // - Measure is not valid so parent is not arranged
+            // - Parent is measured
+            // - Parent has been dequeued from arrange queue so no arrange is performed
+            var child = new LayoutTestControl();
+            var parent = new LayoutTestControl { Child = child };
+            var root = new LayoutTestRoot { Child = parent };
+
+            root.LayoutManager.ExecuteInitialLayoutPass();
+
+            child.DoArrangeOverride = (_, s) =>
+            {
+                parent.InvalidateMeasure();
+                return s;
+            };
+
+            child.InvalidateMeasure();
+            parent.InvalidateMeasure();
+
+            root.LayoutManager.ExecuteLayoutPass();
+
+            Assert.True(child.IsMeasureValid);
+            Assert.True(child.IsArrangeValid);
+            Assert.True(parent.IsMeasureValid);
+            Assert.True(parent.IsArrangeValid);
+        }
     }
 }

tests/Avalonia.IntegrationTests.Appium/ScrollBarTests.cs

@@ -13,7 +13,7 @@ namespace Avalonia.IntegrationTests.Appium
             _session = fixture.Session;
 
             var tabs = _session.FindElementByAccessibilityId("MainTabs");
-            var tab = tabs.FindElementByName("ScrollBarTab");
+            var tab = tabs.FindElementByName("ScrollBar");
             tab.Click();
         }
 

tests/Avalonia.IntegrationTests.Appium/SliderTests.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Globalization;
 using OpenQA.Selenium.Appium;
 using OpenQA.Selenium.Interactions;
 using Xunit;
@@ -15,21 +16,95 @@ namespace Avalonia.IntegrationTests.Appium
             _session = fixture.Session;
 
             var tabs = _session.FindElementByAccessibilityId("MainTabs");
-            var tab = tabs.FindElementByName("SliderTab");
+            var tab = tabs.FindElementByName("Slider");
             tab.Click();
+
+            var reset = _session.FindElementByAccessibilityId("ResetSliders");
+            reset.Click();
+        }
+
+        [Fact]
+        public void Horizontal_Changes_Value_Dragging_Thumb_Right()
+        {
+            var slider = _session.FindElementByAccessibilityId("HorizontalSlider");
+            var thumb = slider.FindElementByAccessibilityId("thumb");
+            var initialThumbRect = thumb.Rect;
+
+            new Actions(_session).ClickAndHold(thumb).MoveByOffset(100, 0).Release().Perform();
+
+            var value = Math.Round(double.Parse(slider.Text, CultureInfo.InvariantCulture));
+            var boundValue = double.Parse(
+                _session.FindElementByAccessibilityId("HorizontalSliderValue").Text,
+                CultureInfo.InvariantCulture);
+
+            Assert.True(value > 50);
+            Assert.Equal(value, boundValue);
+
+            var currentThumbRect = thumb.Rect;
+            Assert.True(currentThumbRect.Left > initialThumbRect.Left);
+        }
+
+        [Fact]
+        public void Horizontal_Changes_Value_Dragging_Thumb_Left()
+        {
+            var slider = _session.FindElementByAccessibilityId("HorizontalSlider");
+            var thumb = slider.FindElementByAccessibilityId("thumb");
+            var initialThumbRect = thumb.Rect;
+
+            new Actions(_session).ClickAndHold(thumb).MoveByOffset(-100, 0).Release().Perform();
+
+            var value = Math.Round(double.Parse(slider.Text, CultureInfo.InvariantCulture));
+            var boundValue = double.Parse(
+                _session.FindElementByAccessibilityId("HorizontalSliderValue").Text,
+                CultureInfo.InvariantCulture);
+
+            Assert.True(value < 50);
+            Assert.Equal(value, boundValue);
+
+            var currentThumbRect = thumb.Rect;
+            Assert.True(currentThumbRect.Left < initialThumbRect.Left);
         }
 
         [Fact]
-        public void Changes_Value_When_Clicking_Increase_Button()
+        public void Horizontal_Changes_Value_When_Clicking_Increase_Button()
         {
-            var slider = _session.FindElementByAccessibilityId("Slider");
+            var slider = _session.FindElementByAccessibilityId("HorizontalSlider");
+            var thumb = slider.FindElementByAccessibilityId("thumb");
+            var initialThumbRect = thumb.Rect;
+
+            new Actions(_session).MoveToElement(slider, 100, 0, MoveToElementOffsetOrigin.Center).Click().Perform();
+
+            var value = Math.Round(double.Parse(slider.Text, CultureInfo.InvariantCulture));
+            var boundValue = double.Parse(
+                _session.FindElementByAccessibilityId("HorizontalSliderValue").Text,
+                CultureInfo.InvariantCulture);
+
+            Assert.True(value > 50);
+            Assert.Equal(value, boundValue);
+
+            var currentThumbRect = thumb.Rect;
+            Assert.True(currentThumbRect.Left > initialThumbRect.Left);
+        }
+
+        [Fact]
+        public void Horizontal_Changes_Value_When_Clicking_Decrease_Button()
+        {
+            var slider = _session.FindElementByAccessibilityId("HorizontalSlider");
+            var thumb = slider.FindElementByAccessibilityId("thumb");
+            var initialThumbRect = thumb.Rect;
+
+            new Actions(_session).MoveToElement(slider, -100, 0, MoveToElementOffsetOrigin.Center).Click().Perform();
 
-            // slider.Text gets the Slider value
-            Assert.True(double.Parse(slider.Text) == 30);
+            var value = Math.Round(double.Parse(slider.Text, CultureInfo.InvariantCulture));
+            var boundValue = double.Parse(
+                _session.FindElementByAccessibilityId("HorizontalSliderValue").Text,
+                CultureInfo.InvariantCulture);
 
-            new Actions(_session).Click(slider).Perform();
+            Assert.True(value < 50);
+            Assert.Equal(value, boundValue);
 
-            Assert.Equal(50, Math.Round(double.Parse(slider.Text)));
+            var currentThumbRect = thumb.Rect;
+            Assert.True(currentThumbRect.Left < initialThumbRect.Left);
         }
     }
 }