From 1fa00c2634d9bfed7e5633e8586120042dda57ff Mon Sep 17 00:00:00 2001
From: JLdgu <jonathan.linstead@devon.gov.uk>
Date: Thu, 13 Aug 2026 14:12:08 +0100
Subject: [PATCH 1/4] Allow triple left click on a  TextBox to select all text

---
 src/MainDemo.Wpf/Fields.xaml                  | 20 +++++-----
 .../TextFieldAssist.cs                        | 39 +++++++++++++++++++
 .../WPF/TextBoxes/TextBoxTests.cs             | 21 ++++++++++
 3 files changed, 70 insertions(+), 10 deletions(-)

diff --git a/src/MainDemo.Wpf/Fields.xaml b/src/MainDemo.Wpf/Fields.xaml
index 68481e35ea..0209417bdd 100644
--- a/src/MainDemo.Wpf/Fields.xaml
+++ b/src/MainDemo.Wpf/Fields.xaml
@@ -99,6 +99,7 @@
           <TextBox VerticalAlignment="Center"
                    materialDesign:TextFieldAssist.HasClearButton="True"
                    materialDesign:TextFieldAssist.PrefixText="$"
+                   materialDesign:TextFieldAssist.SelectAllOnTripleClick="True"
                    materialDesign:TextFieldAssist.SuffixText="mm"
                    Style="{StaticResource MaterialDesignFloatingHintTextBox}"
                    Text="Good stuff">
@@ -182,18 +183,18 @@
           <CheckBox x:Name="TextBoxWrapTextCheckBox"
                     Content="Wrap text"
                     IsChecked="True" />
-          
+
           <TextBox Grid.Row="1"
                    Height="80"
                    MinWidth="280"
                    VerticalAlignment="Stretch"
                    materialDesign:HintAssist.Hint="Multiline text"
                    AcceptsReturn="True"
+                   HorizontalScrollBarVisibility="Auto"
                    SpellCheck.IsEnabled="True"
                    Text="Multiline. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. The quick brown fox jumps over the lazy dog. War and peace. Keep going. Go on. For how long? Not long. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua."
                    TextWrapping="{Binding ElementName=TextBoxWrapTextCheckBox, Path=IsChecked, Converter={StaticResource BoolToTextWrappingConverter}}"
-                   VerticalScrollBarVisibility="Auto"
-                   HorizontalScrollBarVisibility="Auto"/>
+                   VerticalScrollBarVisibility="Auto" />
         </Grid>
       </smtx:XamlDisplay>
 
@@ -690,12 +691,11 @@
     <TextBlock Style="{StaticResource PageSectionTitleTextBlock}" Text="Custom Background" />
 
     <WrapPanel Margin="0,0,0,32" Background="Chocolate">
-      <smtx:XamlDisplay Margin="16"
-                        UniqueKey="fields_custom_background_1">
+      <smtx:XamlDisplay Margin="16" UniqueKey="fields_custom_background_1">
         <TextBox Width="200"
-                 Style="{StaticResource MaterialDesignOutlinedTextBox}"
                  materialDesign:HintAssist.Hint="Hint text"
-                 materialDesign:HintAssist.HintPaddingBrush="Chocolate" />
+                 materialDesign:HintAssist.HintPaddingBrush="Chocolate"
+                 Style="{StaticResource MaterialDesignOutlinedTextBox}" />
         <!-- Set HintAssist.HintPaddingBrush to match the custom background to get correct coloring of the hint padding (when floated) -->
       </smtx:XamlDisplay>
     </WrapPanel>
@@ -704,7 +704,7 @@
     <TextBlock Style="{StaticResource PageSectionTitleTextBlock}" Text="AutoSuggestBox" />
 
     <WrapPanel>
-      <StackPanel  Width="256" Margin="0,0,16,16">
+      <StackPanel Width="256" Margin="0,0,16,16">
         <TextBlock Margin="0,0,0,8"
                    VerticalAlignment="Center"
                    Style="{StaticResource MaterialDesignSubtitle1TextBlock}"
@@ -719,7 +719,7 @@
         </smtx:XamlDisplay>
       </StackPanel>
 
-      <StackPanel  Width="256" Margin="0,0,16,16">
+      <StackPanel Width="256" Margin="0,0,16,16">
         <TextBlock Margin="0,0,0,8"
                    Style="{StaticResource MaterialDesignSubtitle1TextBlock}"
                    Text="AutoSuggestBox with ItemTemplate" />
@@ -774,7 +774,7 @@
         </smtx:XamlDisplay>
       </StackPanel>
 
-      <StackPanel  Width="256" Margin="0,0,16,16">
+      <StackPanel Width="256" Margin="0,0,16,16">
         <TextBlock Margin="0,0,0,8"
                    Style="{StaticResource MaterialDesignSubtitle1TextBlock}"
                    Text="Outlined AutoSuggestBox" />
diff --git a/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs b/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
index aac1a63024..42c0684b30 100644
--- a/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
+++ b/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
@@ -150,6 +150,45 @@ public static class TextFieldAssist
 
     public static bool GetIncludeSpellingSuggestions(TextBoxBase element) => (bool)element.GetValue(IncludeSpellingSuggestionsProperty);
 
+    /// <summary>
+    /// Allow triple click to select all text in a TextBox.
+    /// </summary>
+    public static readonly DependencyProperty SelectAllOnTripleClickProperty =
+        DependencyProperty.RegisterAttached(
+            "SelectAllOnTripleClick",
+            typeof(bool),
+            typeof(TextFieldAssist),
+            new PropertyMetadata(false, OnSelectAllOnTripleClickChanged));
+
+    public static bool GetSelectAllOnTripleClick(DependencyObject obj) =>
+        (bool)obj.GetValue(SelectAllOnTripleClickProperty);
+
+    public static void SetSelectAllOnTripleClick(DependencyObject obj, bool value) =>
+        obj.SetValue(SelectAllOnTripleClickProperty, value);
+
+    private static void OnSelectAllOnTripleClickChanged(
+        DependencyObject d,
+        DependencyPropertyChangedEventArgs e)
+    {
+        if (d is TextBox textBox)
+        {
+            if ((bool)e.NewValue)
+                textBox.PreviewMouseLeftButtonDown += TextBox_PreviewMouseLeftButtonDown;
+            else
+                textBox.PreviewMouseLeftButtonDown -= TextBox_PreviewMouseLeftButtonDown;
+        }
+    }
+
+    private static void TextBox_PreviewMouseLeftButtonDown(
+        object sender,
+        MouseButtonEventArgs e)
+    {
+        if (e.ClickCount == 3 && sender is TextBox textBox)
+        {
+            textBox.SelectAll();
+            e.Handled = true;
+        }
+    }
     /// <summary>
     /// SuffixText dependency property
     /// </summary>
diff --git a/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs b/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs
index 7a248ca4ef..c8dbb4ed9c 100644
--- a/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs
+++ b/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs
@@ -498,6 +498,27 @@ public async Task TextBox_MultiLineAndFixedHeight_RespectsVerticalContentAlignme
     }
 
     [Test]
+    public async Task TextBox_WithSelectAllOnTripleClick_SelectsAllText()
+    {
+        var textBox = await LoadXaml<TextBox>($$"""
+            <TextBox Style="{StaticResource MaterialDesignFilledTextBox}"
+              Text="Some text to select"
+              materialDesign:TextFieldAssist.SelectAllOnTripleClick="True"
+              Width="200" VerticalAlignment="Center" HorizontalAlignment="Center" />
+            """);
+        await textBox.LeftClick();
+        await textBox.LeftClick();
+        await textBox.LeftClick();
+        //await Task.Delay(1000); 
+        await Wait.For(async () =>
+        {
+            string? selectedText = await textBox.GetSelectedText();
+
+            await Assert.That(selectedText).IsEqualTo("Some text to select");
+        });
+    }
+
+        [Test]
     [Description("Issue 3176")]
     public async Task ValidationErrorTemplate_WithChangingErrors_UpdatesValidation()
     {

From fc516bcd8027a8ebdc6dcc28135feb872263caa3 Mon Sep 17 00:00:00 2001
From: JLdgu <114992499+JLdgu@users.noreply.github.com>
Date: Mon, 17 Aug 2026 09:40:53 +0100
Subject: [PATCH 2/4] Update src/MaterialDesignThemes.Wpf/TextFieldAssist.cs

Co-authored-by: Corvin <43533385+corvinsz@users.noreply.github.com>
---
 src/MaterialDesignThemes.Wpf/TextFieldAssist.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs b/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
index 42c0684b30..53eaf2c345 100644
--- a/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
+++ b/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
@@ -170,7 +170,7 @@ private static void OnSelectAllOnTripleClickChanged(
         DependencyObject d,
         DependencyPropertyChangedEventArgs e)
     {
-        if (d is TextBox textBox)
+        if (d is TextBoxBase textBox)
         {
             if ((bool)e.NewValue)
                 textBox.PreviewMouseLeftButtonDown += TextBox_PreviewMouseLeftButtonDown;

From 3fb4d217adf638b8b1840b50bf7bf66b2c544fb7 Mon Sep 17 00:00:00 2001
From: JLdgu <114992499+JLdgu@users.noreply.github.com>
Date: Mon, 17 Aug 2026 09:41:17 +0100
Subject: [PATCH 3/4] Update src/MaterialDesignThemes.Wpf/TextFieldAssist.cs

Co-authored-by: Corvin <43533385+corvinsz@users.noreply.github.com>
---
 src/MaterialDesignThemes.Wpf/TextFieldAssist.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs b/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
index 53eaf2c345..70d518dbeb 100644
--- a/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
+++ b/src/MaterialDesignThemes.Wpf/TextFieldAssist.cs
@@ -183,7 +183,7 @@ private static void TextBox_PreviewMouseLeftButtonDown(
         object sender,
         MouseButtonEventArgs e)
     {
-        if (e.ClickCount == 3 && sender is TextBox textBox)
+        if (e.ClickCount == 3 && sender is TextBoxBase textBox)
         {
             textBox.SelectAll();
             e.Handled = true;

From 9c96e67c3e0d3118c2e7999083560008fdae77f2 Mon Sep 17 00:00:00 2001
From: JLdgu <jonathan.linstead@devon.gov.uk>
Date: Mon, 17 Aug 2026 10:26:20 +0100
Subject: [PATCH 4/4] Add test to ensure that when triple click false not all
 text is selected

Update Demos with dedicated samples
---
 src/MainDemo.Wpf/Fields.xaml                  |  8 ++++-
 src/MaterialDesign3.Demo.Wpf/Fields.xaml      | 13 +++++++--
 .../WPF/TextBoxes/TextBoxTests.cs             | 29 +++++++++++++++++--
 3 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/src/MainDemo.Wpf/Fields.xaml b/src/MainDemo.Wpf/Fields.xaml
index 0209417bdd..58395ddefc 100644
--- a/src/MainDemo.Wpf/Fields.xaml
+++ b/src/MainDemo.Wpf/Fields.xaml
@@ -99,7 +99,6 @@
           <TextBox VerticalAlignment="Center"
                    materialDesign:TextFieldAssist.HasClearButton="True"
                    materialDesign:TextFieldAssist.PrefixText="$"
-                   materialDesign:TextFieldAssist.SelectAllOnTripleClick="True"
                    materialDesign:TextFieldAssist.SuffixText="mm"
                    Style="{StaticResource MaterialDesignFloatingHintTextBox}"
                    Text="Good stuff">
@@ -149,7 +148,14 @@
                    Style="{StaticResource MaterialDesignFloatingHintTextBox}"
                    Text="Some Text" />
         </smtx:XamlDisplay>
+      </DockPanel>
 
+      <DockPanel Style="{StaticResource FieldDockPanel}">
+        <smtx:XamlDisplay UniqueKey="fields_2">
+          <TextBox materialDesign:TextFieldAssist.SelectAllOnTripleClick="True"
+                   Style="{StaticResource MaterialDesignTextBox}"
+                   Text="Triple click to select all text" />
+        </smtx:XamlDisplay>
       </DockPanel>
 
       <DockPanel Style="{StaticResource FieldDockPanel}">
diff --git a/src/MaterialDesign3.Demo.Wpf/Fields.xaml b/src/MaterialDesign3.Demo.Wpf/Fields.xaml
index 6bcfd37bc6..79ac1c13c0 100644
--- a/src/MaterialDesign3.Demo.Wpf/Fields.xaml
+++ b/src/MaterialDesign3.Demo.Wpf/Fields.xaml
@@ -43,7 +43,7 @@
         <ColumnDefinition Width="Auto" />
         <ColumnDefinition Width="155" />
         <ColumnDefinition Width="Auto" />
-        <ColumnDefinition Width="155" />
+        <ColumnDefinition Width="190" />
         <ColumnDefinition Width="*" />
       </Grid.ColumnDefinitions>
 
@@ -54,6 +54,7 @@
         <RowDefinition Height="Auto" />
         <RowDefinition Height="Auto" />
         <RowDefinition Height="Auto" />
+        <RowDefinition Height="Auto" />
       </Grid.RowDefinitions>
 
       <TextBlock Grid.Row="0"
@@ -164,6 +165,14 @@
       </smtx:XamlDisplay>
 
       <smtx:XamlDisplay Grid.Row="4"
+                        Grid.Column="3"
+                        UniqueKey="fields_2">
+          <TextBox materialDesign:TextFieldAssist.SelectAllOnTripleClick="True"
+                   Style="{StaticResource MaterialDesignTextBox}"
+                   Text="Triple click to select all text" />
+        </smtx:XamlDisplay>
+
+      <smtx:XamlDisplay Grid.Row="5"
                         Grid.Column="3"
                         UniqueKey="fields_13">
         <TextBox MinWidth="72"
@@ -171,7 +180,7 @@
                  IsEnabled="False" />
       </smtx:XamlDisplay>
 
-      <smtx:XamlDisplay Grid.Row="5"
+      <smtx:XamlDisplay Grid.Row="6"
                         Grid.Column="3"
                         UniqueKey="fields_15">
         <PasswordBox MinWidth="72"
diff --git a/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs b/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs
index c8dbb4ed9c..2870c158fc 100644
--- a/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs
+++ b/tests/MaterialDesignThemes.UITests/WPF/TextBoxes/TextBoxTests.cs
@@ -498,7 +498,29 @@ public async Task TextBox_MultiLineAndFixedHeight_RespectsVerticalContentAlignme
     }
 
     [Test]
-    public async Task TextBox_WithSelectAllOnTripleClick_SelectsAllText()
+    public async Task TextBox_WithSelectAllOnTripleClick_False_DoesNotSelectAllText()
+    {
+        var textBox = await LoadXaml<TextBox>($$"""
+            <TextBox Style="{StaticResource MaterialDesignFilledTextBox}"
+              Text="Some text to select"
+              materialDesign:TextFieldAssist.SelectAllOnTripleClick="False"
+              Width="200" VerticalAlignment="Center" HorizontalAlignment="Center" />
+            """);
+
+        await textBox.LeftClick();
+        await textBox.LeftClick();
+        await textBox.LeftClick();
+
+        await Wait.For(async () =>
+        {
+            string? selectedText = await textBox.GetSelectedText();
+
+            await Assert.That(selectedText).IsEqualTo("select");
+        });
+    }
+
+    [Test]
+    public async Task TextBox_WithSelectAllOnTripleClick_True_SelectsAllText()
     {
         var textBox = await LoadXaml<TextBox>($$"""
             <TextBox Style="{StaticResource MaterialDesignFilledTextBox}"
@@ -506,10 +528,11 @@ public async Task TextBox_WithSelectAllOnTripleClick_SelectsAllText()
               materialDesign:TextFieldAssist.SelectAllOnTripleClick="True"
               Width="200" VerticalAlignment="Center" HorizontalAlignment="Center" />
             """);
+
         await textBox.LeftClick();
         await textBox.LeftClick();
         await textBox.LeftClick();
-        //await Task.Delay(1000); 
+
         await Wait.For(async () =>
         {
             string? selectedText = await textBox.GetSelectedText();
@@ -518,7 +541,7 @@ await Wait.For(async () =>
         });
     }
 
-        [Test]
+    [Test]
     [Description("Issue 3176")]
     public async Task ValidationErrorTemplate_WithChangingErrors_UpdatesValidation()
     {