Fix TextBox horizontal scrollbar position when VerticalContentAlignment is set to Top

Author: database64128

src/MainDemo.Wpf/Fields.xaml

@@ -340,12 +340,14 @@
 
           <TextBox Height="100"
                    VerticalAlignment="Top"
+                   VerticalContentAlignment="Top"
                    materialDesign:HintAssist.Hint="This is a text area"
                    AcceptsReturn="True"
                    IsEnabled="{Binding Path=IsChecked, ElementName=MaterialDesignOutlinedTextBoxEnabledComboBox}"
                    Style="{StaticResource MaterialDesignOutlinedTextBox}"
-                   TextWrapping="Wrap"
-                   VerticalScrollBarVisibility="Auto" />
+                   TextWrapping="NoWrap"
+                   VerticalScrollBarVisibility="Auto"
+                   HorizontalScrollBarVisibility="Auto" />
         </StackPanel>
       </smtx:XamlDisplay>
 

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.TextBox.xaml

@@ -133,7 +133,7 @@
 
                 <Grid x:Name="ContentGrid"
                       MinHeight="16"
-                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
+                      VerticalAlignment="Stretch">
                   <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="Auto" />
                     <ColumnDefinition Width="Auto" />
@@ -156,7 +156,7 @@
                   <ScrollViewer x:Name="PART_ContentHost"
                                 Grid.Column="2"
                                 HorizontalAlignment="Stretch"
-                                VerticalAlignment="Center"
+                                VerticalAlignment="Stretch"
                                 HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                                 VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                                 Panel.ZIndex="1"

tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs

@@ -536,34 +536,6 @@ public async Task TextBox_WithHintAndValidationError_RespectsPadding(string styl
         recorder.Success();
     }
 
-    [Test]
-    [Arguments(VerticalAlignment.Stretch, VerticalAlignment.Stretch)]
-    [Arguments(VerticalAlignment.Top, VerticalAlignment.Top)]
-    [Arguments(VerticalAlignment.Bottom, VerticalAlignment.Bottom)]
-    [Arguments(VerticalAlignment.Center, VerticalAlignment.Center)]
-    [Description("Issue 3161")]
-    public async Task TextBox_MultiLineAndFixedHeight_RespectsVerticalContentAlignment(VerticalAlignment alignment, VerticalAlignment expectedFloatingHintAlignment)
-    {
-        await using var recorder = new TestRecorder(App);
-
-        var stackPanel = await LoadXaml<StackPanel>($$"""
-            <StackPanel>
-              <TextBox Style="{StaticResource MaterialDesignFilledTextBox}"
-                materialDesign:HintAssist.Hint="Hint text"
-                VerticalContentAlignment="{{alignment}}"
-                AcceptsReturn="True"
-                Height="200" />
-            </StackPanel>
-            """);
-
-        IVisualElement<TextBox> textBox = await stackPanel.GetElement<TextBox>("/TextBox");
-        IVisualElement<Grid> contentGrid = await textBox.GetElement<Grid>("ContentGrid");
-
-        await Assert.That(await contentGrid.GetVerticalAlignment()).IsEqualTo(expectedFloatingHintAlignment);
-
-        recorder.Success();
-    }
-
     [Test]
     [Description("Issue 3176")]
     public async Task ValidationErrorTemplate_WithChangingErrors_UpdatesValidation()