Refactor PasswordBoxAssist to use behavior

Directory.packages.props

@@ -15,6 +15,7 @@
     <PackageVersion Include="Microsoft.NETCore.Platforms" Version="6.0.6" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
     <PackageVersion Include="Microsoft.Toolkit.MVVM" Version="7.1.2" />
+    <PackageVersion Include="Microsoft.Xaml.Behaviors.Wpf" Version="1.1.37" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageVersion Include="Shouldly" Version="4.1.0" />
     <PackageVersion Include="ShowMeTheXAML" Version="2.0.0" />
@@ -26,4 +27,4 @@
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.5" />
     <PackageVersion Include="Xunit.StaFact" Version="1.1.11" />
   </ItemGroup>
-</Project>
+</Project>

MaterialDesignThemes.Wpf/MaterialDesignThemes.Wpf.csproj

@@ -24,6 +24,9 @@
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Xaml.Behaviors.Wpf" />
+  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\MaterialDesignColors.Wpf\MaterialDesignColors.Wpf.csproj" />
   </ItemGroup>

MaterialDesignThemes.Wpf/PasswordBoxAssist.cs

@@ -1,8 +1,10 @@
-using System.Windows.Data;
+using System.Windows.Data;
+using System.Windows.Documents;
+using Microsoft.Xaml.Behaviors;
 
 namespace MaterialDesignThemes.Wpf;
 
-public static class PasswordBoxAssist
+public class PasswordBoxAssist : Behavior<PasswordBox>
 {
     public static readonly DependencyProperty PasswordMaskedIconProperty = DependencyProperty.RegisterAttached(
         "PasswordMaskedIcon", typeof(PackIconKind), typeof(PasswordBoxAssist), new FrameworkPropertyMetadata(PackIconKind.EyeOff, FrameworkPropertyMetadataOptions.Inherits));
@@ -24,45 +26,67 @@ public static class PasswordBoxAssist
     public static void SetPassword(DependencyObject element, string value) => element.SetValue(PasswordProperty, value);
     public static string GetPassword(DependencyObject element) => (string)element.GetValue(PasswordProperty);
 
-    // Internal attached DP used to initially wire up the connection between the masked PasswordBox content and the clear text TextBox content
-    internal static readonly DependencyProperty InitialPasswordProperty = DependencyProperty.RegisterAttached(
-        "InitialPassword", typeof(string), typeof(PasswordBoxAssist), new PropertyMetadata(default(string)));
-    internal static void SetInitialPassword(DependencyObject element, string value) => element.SetValue(InitialPasswordProperty, value);
-    internal static string GetInitialPassword(DependencyObject element) => (string)element.GetValue(InitialPasswordProperty);
+    private static readonly DependencyProperty IsChangingProperty = DependencyProperty.RegisterAttached(
+        "IsChanging", typeof(bool), typeof(PasswordBoxAssist), new UIPropertyMetadata(false));
+    private static void SetIsChanging(UIElement element, bool value) => element.SetValue(IsChangingProperty, value);
+    private static bool GetIsChanging(UIElement element) => (bool)element.GetValue(IsChangingProperty);
+
+    private static readonly DependencyProperty SelectionProperty = DependencyProperty.RegisterAttached(
+        "Selection", typeof(TextSelection), typeof(PasswordBoxAssist), new UIPropertyMetadata(default(TextSelection)));
+    private static void SetSelection(DependencyObject obj, TextSelection? value) => obj.SetValue(SelectionProperty, value);
+    private static TextSelection? GetSelection(DependencyObject obj) => (TextSelection?)obj.GetValue(SelectionProperty);
 
-    private static readonly DependencyProperty IsPasswordInitializedProperty = DependencyProperty.RegisterAttached(
-        "IsPasswordInitialized", typeof(bool), typeof(PasswordBoxAssist), new PropertyMetadata(false));
+    private static readonly DependencyProperty RevealedPasswordTextBoxProperty = DependencyProperty.RegisterAttached(
+        "RevealedPasswordTextBox", typeof(TextBox), typeof(PasswordBoxAssist), new UIPropertyMetadata(default(TextBox)));
+    private static void SetRevealedPasswordTextBox(DependencyObject obj, TextBox? value) => obj.SetValue(RevealedPasswordTextBoxProperty, value);
+    private static TextBox? GetRevealedPasswordTextBox(DependencyObject obj) => (TextBox?)obj.GetValue(RevealedPasswordTextBoxProperty);
 
-    private static readonly DependencyProperty SettingPasswordProperty = DependencyProperty.RegisterAttached(
-        "SettingPassword", typeof(bool), typeof(PasswordBoxAssist), new PropertyMetadata(false));
 
-    private static void HandlePasswordChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    /// <summary>
+    /// Handles changes to the 'Password' attached property.
+    /// </summary>
+    private static void HandlePasswordChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
     {
-        if (d is not PasswordBox passwordBox)
-            return;
-
-        if ((bool)passwordBox.GetValue(SettingPasswordProperty))
-            return;
+        if (sender is PasswordBox targetPasswordBox)
+        {
+            targetPasswordBox.PasswordChanged -= PasswordBoxPasswordChanged;
+            if (!GetIsChanging(targetPasswordBox))
+            {
+                targetPasswordBox.Password = (string)e.NewValue;
+            }
+            targetPasswordBox.PasswordChanged += PasswordBoxPasswordChanged;
+        }
+    }
 
-        if (!(bool)passwordBox.GetValue(IsPasswordInitializedProperty))
+    /// <summary>
+    /// Handle the 'PasswordChanged'-event on the PasswordBox
+    /// </summary>
+    private static void PasswordBoxPasswordChanged(object sender, RoutedEventArgs e)
+    {
+        if (sender is PasswordBox passwordBox)
         {
-            passwordBox.SetValue(IsPasswordInitializedProperty, true);
-            WeakEventManager<PasswordBox, RoutedEventArgs>.AddHandler(passwordBox, nameof(PasswordBox.PasswordChanged), HandlePasswordChanged);
+            SetIsChanging(passwordBox, true);
+            SetPassword(passwordBox, passwordBox.Password);
+            SetIsChanging(passwordBox, false);
         }
-        passwordBox.Password = e.NewValue as string;
     }
 
-    private static void HandlePasswordChanged(object? sender, RoutedEventArgs e)
+    private void PasswordBoxLoaded(object sender, RoutedEventArgs e) => SetPassword(AssociatedObject, AssociatedObject.Password);
+
+    protected override void OnAttached()
     {
-        if (sender is not PasswordBox passwordBox)
-            return;
+        base.OnAttached();
+        AssociatedObject.PasswordChanged += PasswordBoxPasswordChanged;
+        AssociatedObject.Loaded += PasswordBoxLoaded;
+    }
 
-        passwordBox.SetValue(SettingPasswordProperty, true);
-        string currentPassword = GetPassword(passwordBox);
-        if (currentPassword != passwordBox.Password)
+    protected override void OnDetaching()
+    {
+        if (AssociatedObject != null)
         {
-            SetPassword(passwordBox, passwordBox.Password);
+            AssociatedObject.Loaded -= PasswordBoxLoaded;
+            AssociatedObject.PasswordChanged -= PasswordBoxPasswordChanged;
         }
-        passwordBox.SetValue(SettingPasswordProperty, false);
+        base.OnDetaching();
     }
 }

MaterialDesignThemes.Wpf/StylizedBehaviorCollection.cs

@@ -0,0 +1,8 @@
+using Microsoft.Xaml.Behaviors;
+
+namespace MaterialDesignThemes.Wpf;
+
+public class StylizedBehaviorCollection : FreezableCollection<Behavior>
+{
+    protected override Freezable CreateInstanceCore() => new StylizedBehaviorCollection();
+}

MaterialDesignThemes.Wpf/StylizedBehaviors.cs

@@ -0,0 +1,122 @@
+using Microsoft.Xaml.Behaviors;
+
+namespace MaterialDesignThemes.Wpf;
+
+internal class StylizedBehaviors
+{
+    private static readonly DependencyProperty OriginalBehaviorProperty = DependencyProperty.RegisterAttached(
+        "OriginalBehavior", typeof(Behavior), typeof(StylizedBehaviors), new UIPropertyMetadata(null));
+    private static void SetOriginalBehavior(DependencyObject obj, Behavior? value) => obj.SetValue(OriginalBehaviorProperty, value);
+    private static Behavior? GetOriginalBehavior(DependencyObject obj) => (Behavior?)obj.GetValue(OriginalBehaviorProperty);
+
+    internal static readonly DependencyProperty BehaviorsProperty = DependencyProperty.RegisterAttached(
+        "Behaviors", typeof(StylizedBehaviorCollection), typeof(StylizedBehaviors), new FrameworkPropertyMetadata(null, OnPropertyChanged));
+    internal static void SetBehaviors(DependencyObject uie, StylizedBehaviorCollection? value) => uie.SetValue(BehaviorsProperty, value);
+    internal static StylizedBehaviorCollection? GetBehaviors(DependencyObject uie) => (StylizedBehaviorCollection?)uie.GetValue(BehaviorsProperty);
+
+    private static void OnPropertyChanged(DependencyObject dpo, DependencyPropertyChangedEventArgs e)
+    {
+        if (dpo is not FrameworkElement frameworkElement)
+        {
+            return;
+        }
+
+        var newBehaviors = e.NewValue as StylizedBehaviorCollection;
+        var oldBehaviors = e.OldValue as StylizedBehaviorCollection;
+        if (newBehaviors == oldBehaviors)
+        {
+            return;
+        }
+
+        var itemBehaviors = Interaction.GetBehaviors(frameworkElement);
+        frameworkElement.Unloaded -= FrameworkElementUnloaded;
+        if (oldBehaviors != null)
+        {
+            foreach (var behavior in oldBehaviors)
+            {
+                int index = GetIndexOf(itemBehaviors, behavior);
+                if (index >= 0)
+                {
+                    itemBehaviors.RemoveAt(index);
+                }
+            }
+        }
+
+        if (newBehaviors != null)
+        {
+            foreach (var behavior in newBehaviors)
+            {
+                int index = GetIndexOf(itemBehaviors, behavior);
+                if (index < 0)
+                {
+                    var clone = (Behavior)behavior.Clone();
+                    SetOriginalBehavior(clone, behavior);
+                    itemBehaviors.Add(clone);
+                }
+            }
+        }
+
+        if (itemBehaviors.Count > 0)
+        {
+            frameworkElement.Unloaded += FrameworkElementUnloaded;
+        }
+    }
+
+    private static void FrameworkElementUnloaded(object sender, RoutedEventArgs e)
+    {
+        // BehaviorCollection doesn't call Detach, so we do this
+        if (sender is not FrameworkElement frameworkElement)
+        {
+            return;
+        }
+
+        var itemBehaviors = Interaction.GetBehaviors(frameworkElement);
+        foreach (var behavior in itemBehaviors)
+        {
+            behavior.Detach();
+        }
+
+        frameworkElement.Loaded += FrameworkElementLoaded;
+    }
+
+    private static void FrameworkElementLoaded(object sender, RoutedEventArgs e)
+    {
+        if (sender is not FrameworkElement frameworkElement)
+        {
+            return;
+        }
+
+        frameworkElement.Loaded -= FrameworkElementLoaded;
+        var itemBehaviors = Interaction.GetBehaviors(frameworkElement);
+        foreach (var behavior in itemBehaviors)
+        {
+            behavior.Attach(frameworkElement);
+        }
+    }
+
+    private static int GetIndexOf(BehaviorCollection itemBehaviors, Behavior behavior)
+    {
+        int index = -1;
+
+        var originalBehavior = GetOriginalBehavior(behavior);
+
+        for (int i = 0; i < itemBehaviors.Count; i++)
+        {
+            var currentBehavior = itemBehaviors[i];
+            if (currentBehavior == behavior || currentBehavior == originalBehavior)
+            {
+                index = i;
+                break;
+            }
+
+            var currentOriginalBehavior = GetOriginalBehavior(currentBehavior);
+            if (currentOriginalBehavior == behavior || currentOriginalBehavior == originalBehavior)
+            {
+                index = i;
+                break;
+            }
+        }
+
+        return index;
+    }
+}

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.PasswordBox.xaml

@@ -1,8 +1,10 @@
-<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters"
                     xmlns:internal="clr-namespace:MaterialDesignThemes.Wpf.Internal"
-                    xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf">
+                    xmlns:behaviors="http://schemas.microsoft.com/xaml/behaviors"
+                    xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf"
+                    xmlns:internalbehaviors="clr-namespace:MaterialDesignThemes.Wpf.Behaviors">
   <ResourceDictionary.MergedDictionaries>
     <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.ValidationErrorTemplate.xaml" />
     <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.Menu.xaml" />
@@ -443,6 +445,13 @@
     <Setter Property="wpf:TextFieldAssist.UnderlineBrush" Value="{DynamicResource PrimaryHueMidBrush}" />
     <Setter Property="wpf:TextFieldAssist.CharacterCounterStyle" Value="{StaticResource MaterialDesignPasswordCharacterCounterTextBlock}" />
     <Setter Property="wpf:TextFieldAssist.CharacterCounterVisibility" Value="Hidden" />
+    <Setter Property="wpf:StylizedBehaviors.Behaviors">
+      <Setter.Value>
+        <wpf:StylizedBehaviorCollection>
+          <wpf:PasswordBoxAssist />
+        </wpf:StylizedBehaviorCollection>
+      </Setter.Value>
+    </Setter>
   </Style>
 
   <Style x:Key="MaterialDesignFloatingHintPasswordBox"
@@ -946,13 +955,18 @@
     <Setter Property="internal:ClearText.HandlesClearCommand" Value="True" />
     <Setter Property="wpf:HintAssist.Foreground" Value="{DynamicResource PrimaryHueMidBrush}" />
     <Setter Property="wpf:HintAssist.HelperTextStyle" Value="{StaticResource MaterialDesignPasswordHelperTextBlock}" />
-    <Setter Property="wpf:PasswordBoxAssist.InitialPassword" Value="" />
     <Setter Property="wpf:PasswordBoxAssist.IsPasswordRevealed" Value="False" />
-    <Setter Property="wpf:PasswordBoxAssist.Password" Value="{Binding RelativeSource={RelativeSource Self}, Path=(wpf:PasswordBoxAssist.InitialPassword)}" />
     <Setter Property="wpf:TextFieldAssist.TextBoxViewMargin" Value="{x:Static wpf:Constants.DefaultTextBoxViewMargin}" />
     <Setter Property="wpf:TextFieldAssist.UnderlineBrush" Value="{DynamicResource PrimaryHueMidBrush}" />
     <Setter Property="wpf:TextFieldAssist.CharacterCounterStyle" Value="{StaticResource MaterialDesignPasswordCharacterCounterTextBlock}" />
     <Setter Property="wpf:TextFieldAssist.CharacterCounterVisibility" Value="Hidden" />
+    <Setter Property="wpf:StylizedBehaviors.Behaviors">
+      <Setter.Value>
+        <wpf:StylizedBehaviorCollection>
+          <wpf:PasswordBoxAssist />
+        </wpf:StylizedBehaviorCollection>
+      </Setter.Value>
+    </Setter>
   </Style>
 
   <Style x:Key="MaterialDesignFloatingHintRevealPasswordBox"