fix(tabview): Fix ScrollViewer-related issues

davidjohnoliver · davidjohnoliver · commit fe8b659a9587 · 2021-02-03T09:55:26.000-05:00
- ensure ScrollBar is correctly hidden in tab row
 - ensure increase/decrease buttons have correct initial visual state
diff --git a/src/Uno.UI.FluentTheme/Resources/PriorityDefault/TabView.xaml b/src/Uno.UI.FluentTheme/Resources/PriorityDefault/TabView.xaml
@@ -7,6 +7,7 @@
     xmlns:contract7Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)"
     xmlns:contract7NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,7)"
     xmlns:local="using:Microsoft.UI.Xaml.Controls"
+    xmlns:uno="using:Uno.UI.Xaml.Controls"
 	xmlns:ios="http://platform.uno/ios"
     xmlns:primitives="using:Microsoft.UI.Xaml.Controls.Primitives">
 
@@ -170,7 +171,10 @@
     </Style>
 
     <Style x:Name="TabScrollViewerStyle" TargetType="ScrollViewer">
-        <Setter Property="Template">
+		<!--Uno workaround: ScrollBars are deliberately omitted from the style because they shouldn't appear-->
+		<Setter Property="uno:ScrollViewer.ShouldFallBackToNativeScrollBars"
+				Value="False"/>
+		<Setter Property="Template">
             <Setter.Value>
                 <ControlTemplate TargetType="ScrollViewer">
                     <Border x:Name="Root"
diff --git a/src/Uno.UI.FluentTheme/themeresources.xaml b/src/Uno.UI.FluentTheme/themeresources.xaml
@@ -1,4 +1,4 @@
-<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:media="using:Microsoft.UI.Xaml.Media" xmlns:controls="using:Microsoft.UI.Xaml.Controls" xmlns:primitives="using:Microsoft.UI.Xaml.Controls.Primitives" xmlns:contract4Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,4)" xmlns:contract7Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:contract7NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:primitiveContract7Present="using:Microsoft.UI.Xaml.Controls.Primitives?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:contract4NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,4)" xmlns:wasm="http://uno.ui/wasm" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:unouwp="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Uno.WinUI,1)" xmlns:win="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:contract6Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,6)" xmlns:ios="http://platform.uno/ios" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:media="using:Microsoft.UI.Xaml.Media" xmlns:controls="using:Microsoft.UI.Xaml.Controls" xmlns:primitives="using:Microsoft.UI.Xaml.Controls.Primitives" xmlns:contract4Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,4)" xmlns:contract7Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:contract7NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:primitiveContract7Present="using:Microsoft.UI.Xaml.Controls.Primitives?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:contract4NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,4)" xmlns:wasm="http://uno.ui/wasm" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:unouwp="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Uno.WinUI,1)" xmlns:win="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:contract6Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,6)" xmlns:uno="using:Uno.UI.Xaml.Controls" xmlns:ios="http://platform.uno/ios" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
   <ResourceDictionary.ThemeDictionaries>
     <ResourceDictionary x:Key="Default">
       <SolidColorBrush x:Key="SystemControlTransparentBrush" Color="Transparent" />
@@ -20108,6 +20108,8 @@
     </Setter>
   </Style>
   <Style x:Name="TabScrollViewerStyle" TargetType="ScrollViewer">
+    <!--Uno workaround: ScrollBars are deliberately omitted from the style because they shouldn't appear-->
+    <Setter Property="uno:ScrollViewer.ShouldFallBackToNativeScrollBars" Value="False" />
     <Setter Property="Template">
       <Setter.Value>
         <ControlTemplate TargetType="ScrollViewer">
@@ -21368,4 +21370,4 @@
     </Setter>
   </Style>
   <Style TargetType="controls:TwoPaneView" BasedOn="{StaticResource DefaultTwoPaneViewStyle}" />
-</ResourceDictionary>
+</ResourceDictionary>
diff --git a/src/Uno.UI/Microsoft/UI/Xaml/Controls/TabView/TabView.cs b/src/Uno.UI/Microsoft/UI/Xaml/Controls/TabView/TabView.cs
@@ -76,6 +76,8 @@ public partial class TabView : Control
 		private long m_listViewCanReorderItemsPropertyChangedRevoker;
 		private long m_listViewAllowDropPropertyChangedRevoker;
 
+		private long m_ScrollViewerScrollableWidthPropertyChangedRevoker; // Uno workaround
+
 		public TabView()
 		{
 			m_dispatcherHelper = new DispatcherHelper(this);
@@ -396,6 +398,7 @@ private void UnhookEventsAndClearFields()
 			{
 				m_scrollViewer.Loaded -= OnScrollViewerLoaded;
 				m_scrollViewer.ViewChanged -= OnScrollViewerViewChanged;
+				m_scrollViewer.UnregisterPropertyChangedCallback(ScrollViewer.ScrollableWidthProperty, m_ScrollViewerScrollableWidthPropertyChangedRevoker); // Uno workaround
 			}
 
 			if (m_scrollDecreaseButton != null)
@@ -557,6 +560,12 @@ ItemsPresenter GetItemsPresenter(ListView listView)
 					{
 						scrollViewer.Loaded += OnScrollViewerLoaded;
 					}
+					// Uno workaround: Since Loaded is called before measure, the increase/decrease button visibility is not initially set
+					// properly unless we subscribe to ScrollableWidth changing.
+					m_ScrollViewerScrollableWidthPropertyChangedRevoker = scrollViewer.RegisterPropertyChangedCallback(
+						ScrollViewer.ScrollableWidthProperty,
+						(_, __) => UpdateScrollViewerDecreaseAndIncreaseButtonsViewState()
+					);
 				}
 			}
 		}
diff --git a/src/Uno.UI/Microsoft/UI/Xaml/Controls/TabView/TabView.xaml b/src/Uno.UI/Microsoft/UI/Xaml/Controls/TabView/TabView.xaml
@@ -174,8 +174,11 @@
         </Setter>
     </Style>
 
-    <Style x:Name="TabScrollViewerStyle" TargetType="ScrollViewer">
-        <Setter Property="Template">
+	<Style x:Name="TabScrollViewerStyle" TargetType="ScrollViewer">
+		<!--Uno workaround: ScrollBars are deliberately omitted from the style because they shouldn't appear-->
+		<Setter Property="uno:ScrollViewer.ShouldFallBackToNativeScrollBars"
+				Value="False"/>
+		<Setter Property="Template">
             <Setter.Value>
                 <ControlTemplate TargetType="ScrollViewer">
                     <Border x:Name="Root"

Original file line number	Diff line number	Diff line change
`@@ -76,6 +76,8 @@ public partial class TabView : Control`
`76`	`76`	`private long m_listViewCanReorderItemsPropertyChangedRevoker;`
`77`	`77`	`private long m_listViewAllowDropPropertyChangedRevoker;`
`78`	`78`
	`79`	`+ private long m_ScrollViewerScrollableWidthPropertyChangedRevoker; // Uno workaround`
	`80`	`+`
`79`	`81`	`public TabView()`
`80`	`82`	`{`
`81`	`83`	`m_dispatcherHelper = new DispatcherHelper(this);`
`@@ -396,6 +398,7 @@ private void UnhookEventsAndClearFields()`
`396`	`398`	`{`
`397`	`399`	`m_scrollViewer.Loaded -= OnScrollViewerLoaded;`
`398`	`400`	`m_scrollViewer.ViewChanged -= OnScrollViewerViewChanged;`
	`401`	`+ m_scrollViewer.UnregisterPropertyChangedCallback(ScrollViewer.ScrollableWidthProperty, m_ScrollViewerScrollableWidthPropertyChangedRevoker); // Uno workaround`
`399`	`402`	`}`
`400`	`403`
`401`	`404`	`if (m_scrollDecreaseButton != null)`
`@@ -557,6 +560,12 @@ ItemsPresenter GetItemsPresenter(ListView listView)`
`557`	`560`	`{`
`558`	`561`	`scrollViewer.Loaded += OnScrollViewerLoaded;`
`559`	`562`	`}`
	`563`	`+ // Uno workaround: Since Loaded is called before measure, the increase/decrease button visibility is not initially set`
	`564`	`+ // properly unless we subscribe to ScrollableWidth changing.`
	`565`	`+ m_ScrollViewerScrollableWidthPropertyChangedRevoker = scrollViewer.RegisterPropertyChangedCallback(`
	`566`	`+ ScrollViewer.ScrollableWidthProperty,`
	`567`	`+ (_, __) => UpdateScrollViewerDecreaseAndIncreaseButtonsViewState()`
	`568`	`+ );`
`560`	`569`	`}`
`561`	`570`	`}`
`562`	`571`	`}`