Refactor PasswordBoxAssist.Password to use behaviors (issue 2930)

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="1.1.39" />
     <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.UITests/Samples/PasswordBox/BoundPasswordBox.xaml

@@ -0,0 +1,19 @@
+<UserControl x:Class="MaterialDesignThemes.UITests.Samples.PasswordBox.BoundPasswordBox"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:local="clr-namespace:MaterialDesignThemes.UITests.Samples.PasswordBox"
+             xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
+             mc:Ignorable="d"
+             d:DataContext="{d:DesignInstance local:BoundPasswordBoxViewModel, IsDesignTimeCreatable=False}"
+             d:DesignHeight="450" d:DesignWidth="800">
+  <Grid>
+    <PasswordBox x:Name="PasswordBox"
+                 Width="400"
+                 HorizontalAlignment="Center"
+                 VerticalAlignment="Center"
+                 Style="{StaticResource {x:Type PasswordBox}}"
+                 materialDesign:PasswordBoxAssist.Password="{Binding Password, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
+  </Grid>
+</UserControl>

MaterialDesignThemes.UITests/Samples/PasswordBox/BoundPasswordBox.xaml.cs

@@ -0,0 +1,38 @@
+namespace MaterialDesignThemes.UITests.Samples.PasswordBox;
+
+public partial class BoundPasswordBox
+{
+
+
+    public string? ViewModelPassword
+    {
+        get => ((BoundPasswordBoxViewModel) DataContext).Password;
+        set => ((BoundPasswordBoxViewModel) DataContext).Password = value;
+    }
+
+
+    private bool _useRevealStyle;
+    public bool UseRevealStyle
+    {
+        get => _useRevealStyle;
+        set
+        {
+            _useRevealStyle = value;
+            if (_useRevealStyle)
+            {
+                PasswordBox.Style = (Style)PasswordBox.FindResource("MaterialDesignFloatingHintRevealPasswordBox");
+            }
+            else
+            {
+                PasswordBox.ClearValue(StyleProperty);
+            }
+
+        }
+    }
+
+    public BoundPasswordBox()
+    {
+        DataContext = new BoundPasswordBoxViewModel();
+        InitializeComponent();
+    }
+}

MaterialDesignThemes.UITests/Samples/PasswordBox/BoundPasswordBoxViewModel.cs

@@ -0,0 +1,9 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace MaterialDesignThemes.UITests.Samples.PasswordBox;
+
+internal partial class BoundPasswordBoxViewModel : ObservableObject
+{
+    [ObservableProperty]
+    private string? _password;
+}

MaterialDesignThemes.UITests/Samples/PasswordBox/BoundPasswordBoxWindow.xaml

@@ -0,0 +1,22 @@
+<Window x:Class="MaterialDesignThemes.UITests.Samples.PasswordBox.BoundPasswordBoxWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:local="clr-namespace:MaterialDesignThemes.UITests.Samples.PasswordBox"
+        xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
+        mc:Ignorable="d"
+        Height="450"
+        Width="800"
+        Title="BoundPasswordBoxWindow"
+        Background="{DynamicResource MaterialDesignPaper}"
+        FontFamily="{materialDesign:MaterialDesignFont}"
+        TextElement.FontSize="13"
+        TextElement.FontWeight="Regular"
+        TextElement.Foreground="{DynamicResource MaterialDesignBody}"
+        TextOptions.TextFormattingMode="Ideal"
+        TextOptions.TextRenderingMode="Auto"
+        WindowStartupLocation="CenterScreen"
+        Loaded="BoundPasswordBoxWindow_OnLoaded">
+    <local:BoundPasswordBox />
+</Window>

MaterialDesignThemes.UITests/Samples/PasswordBox/BoundPasswordBoxWindow.xaml.cs

@@ -0,0 +1,14 @@
+namespace MaterialDesignThemes.UITests.Samples.PasswordBox;
+
+public partial class BoundPasswordBoxWindow
+{
+    public BoundPasswordBoxWindow() => InitializeComponent();
+
+    private void BoundPasswordBoxWindow_OnLoaded(object sender, RoutedEventArgs e)
+    {
+        Activate();
+        Topmost = true;
+        Topmost = false;
+        Focus();
+    }
+}

MaterialDesignThemes.UITests/WPF/PasswordBoxes/PasswordBoxTests.cs

@@ -1,4 +1,5 @@
 using System.ComponentModel;
+using MaterialDesignThemes.UITests.Samples.PasswordBox;
 
 namespace MaterialDesignThemes.UITests.WPF.PasswordBoxes
 {
@@ -83,42 +84,36 @@ await Wait.For(async () =>
         }
 
         [Fact]
-        [Description("PR 2828")]
+        [Description("PR 2828 and Issue 2930")]
         public async Task RevealPasswordBox_WithBoundPasswordProperty_RespectsThreeWayBinding()
         {
             await using var recorder = new TestRecorder(App);
 
-            var grid = await LoadXaml<Grid>(@"
-<Grid Margin=""30"">
-  <StackPanel Orientation=""Vertical"">
-    <TextBox x:Name=""BoundPassword"" />
-    <PasswordBox x:Name=""PasswordBox""
-         materialDesign:PasswordBoxAssist.Password=""{Binding ElementName=BoundPassword, Path=Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}""
-         Style=""{StaticResource MaterialDesignFloatingHintRevealPasswordBox}""/>
-  </StackPanel>
-</Grid>");
-            var boundPasswordTextBox = await grid.GetElement<TextBox>("BoundPassword"); // Serves as the "VM" in this test
-            var passwordBox = await grid.GetElement<PasswordBox>("PasswordBox");
+            await App.InitializeWithMaterialDesign();
+            IWindow window = await App.CreateWindow<BoundPasswordBoxWindow>();
+            var userControl = await window.GetElement<BoundPasswordBox>();
+            await userControl.SetProperty(nameof(BoundPasswordBox.UseRevealStyle), true);
+            var passwordBox = await userControl.GetElement<PasswordBox>("PasswordBox");
             var clearTextPasswordTextBox = await passwordBox.GetElement<TextBox>("RevealPasswordTextBox");
             var revealPasswordButton = await passwordBox.GetElement<ToggleButton>("RevealPasswordButton");
 
-            // Act 1 (Update in VM updates PasswordBox and RevealPasswordTextBox)
-            await boundPasswordTextBox.SendKeyboardInput($"1");
-            string? boundText1 = await boundPasswordTextBox.GetProperty<string>(TextBox.TextProperty);
+            // Act 1 (Update in PasswordBox updates VM and RevealPasswordTextBox)
+            await passwordBox.SendKeyboardInput($"1");
+            string? boundText1 = await userControl.GetProperty<string>(nameof(BoundPasswordBox.ViewModelPassword));
             string? password1 = await passwordBox.GetProperty<string>(nameof(PasswordBox.Password));
             string? clearTextPassword1 = await clearTextPasswordTextBox.GetProperty<string>(TextBox.TextProperty);
 
-            // Act 2 (Update in PasswordBox updates VM and RevealPasswordTextBox)
-            await passwordBox.SendKeyboardInput($"2");
-            string? boundText2 = await boundPasswordTextBox.GetProperty<string>(TextBox.TextProperty);
-            string? password2 = await passwordBox.GetProperty<string>(nameof(PasswordBox.Password));
-            string? clearTextPassword2 = await clearTextPasswordTextBox.GetProperty<string>(TextBox.TextProperty);
-
             // Act 2 (Update in RevealPasswordTextBox updates PasswordBox and VM)
             await revealPasswordButton.LeftClick();
             await Task.Delay(50);   // Wait for the "clear text TextBox" to become visible
-            await clearTextPasswordTextBox.SendKeyboardInput($"3");
-            string? boundText3 = await boundPasswordTextBox.GetProperty<string>(TextBox.TextProperty);
+            await clearTextPasswordTextBox.SendKeyboardInput($"2");
+            string? boundText2 = await userControl.GetProperty<string>(nameof(BoundPasswordBox.ViewModelPassword));
+            string? password2 = await passwordBox.GetProperty<string>(nameof(PasswordBox.Password));
+            string? clearTextPassword2 = await clearTextPasswordTextBox.GetProperty<string>(TextBox.TextProperty);
+
+            // Act 3 (Update in VM updates PasswordBox and RevealPasswordTextBox)
+            await userControl.SetProperty(nameof(BoundPasswordBox.ViewModelPassword), "3");
+            string? boundText3 = await userControl.GetProperty<string>(nameof(BoundPasswordBox.ViewModelPassword));
             string? password3 = await passwordBox.GetProperty<string>(nameof(PasswordBox.Password));
             string? clearTextPassword3 = await clearTextPasswordTextBox.GetProperty<string>(TextBox.TextProperty);
 
@@ -127,15 +122,47 @@ public async Task RevealPasswordBox_WithBoundPasswordProperty_RespectsThreeWayBi
             Assert.Equal("1", password1);
             Assert.Equal("1", clearTextPassword1);
 
-            Assert.Equal("21", boundText2);
-            Assert.Equal("21", password2);
-            Assert.Equal("21", clearTextPassword2);
+            Assert.Equal("12", boundText2);
+            Assert.Equal("12", password2);
+            Assert.Equal("12", clearTextPassword2);
 
-            Assert.Equal("321", boundText3);
-            Assert.Equal("321", password3);
-            Assert.Equal("321", clearTextPassword3);
+            Assert.Equal("3", boundText3);
+            Assert.Equal("3", password3);
+            Assert.Equal("3", clearTextPassword3);
 
             recorder.Success();
         }
+
+        [Fact]
+        [Description("Issue 2930")]
+        public async Task PasswordBox_WithBoundPasswordProperty_RespectsBinding()
+        {
+            await using var recorder = new TestRecorder(App);
+
+            await App.InitializeWithMaterialDesign();
+            IWindow window = await App.CreateWindow<BoundPasswordBoxWindow>();
+            var userControl = await window.GetElement<BoundPasswordBox>();
+            await userControl.SetProperty(nameof(BoundPasswordBox.UseRevealStyle), false);
+            var passwordBox = await userControl.GetElement<PasswordBox>("PasswordBox");
+
+            // Act 1 (Update in PasswordBox updates VM)
+            await passwordBox.SendKeyboardInput($"1");
+            string? boundText1 = await userControl.GetProperty<string>(nameof(BoundPasswordBox.ViewModelPassword));
+            string? password1 = await passwordBox.GetProperty<string>(nameof(PasswordBox.Password));
+
+            // Act 2 (Update in VM updates PasswordBox)
+            await userControl.SetProperty(nameof(BoundPasswordBox.ViewModelPassword), "2");
+            string? boundText2 = await userControl.GetProperty<string>(nameof(BoundPasswordBox.ViewModelPassword));
+            string? password2 = await passwordBox.GetProperty<string>(nameof(PasswordBox.Password));
+
+            // Assert
+            Assert.Equal("1", boundText1);
+            Assert.Equal("1", password1);
+
+            Assert.Equal("2", boundText2);
+            Assert.Equal("2", password2);
+
+            recorder.Success();
+        } 
     }
 }

MaterialDesignThemes.Wpf/BehaviorCollection.cs

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

MaterialDesignThemes.Wpf/Behaviors/PasswordBoxBehavior.cs

@@ -0,0 +1,23 @@
+using Microsoft.Xaml.Behaviors;
+
+namespace MaterialDesignThemes.Wpf.Behaviors;
+
+internal class PasswordBoxBehavior : Behavior<PasswordBox>
+{
+    private void PasswordBoxLoaded(object sender, RoutedEventArgs e) => PasswordBoxAssist.SetPassword(AssociatedObject, AssociatedObject.Password);
+
+    protected override void OnAttached()
+    {
+        base.OnAttached();
+        AssociatedObject.Loaded += PasswordBoxLoaded;
+    }
+
+    protected override void OnDetaching()
+    {
+        if (AssociatedObject != null)
+        {
+            AssociatedObject.Loaded -= PasswordBoxLoaded;
+        }
+        base.OnDetaching();
+    }
+}

MaterialDesignThemes.Wpf/Behaviors/PasswordBoxRevealTextBoxBehavior.cs

@@ -0,0 +1,97 @@
+using System.Reflection;
+using System.Windows.Documents;
+using Microsoft.Xaml.Behaviors;
+
+namespace MaterialDesignThemes.Wpf.Behaviors;
+
+internal class PasswordBoxRevealTextBoxBehavior : Behavior<TextBox>
+{
+    private static readonly DependencyProperty SelectionProperty = DependencyProperty.RegisterAttached(
+        "Selection", typeof(TextSelection), typeof(PasswordBoxRevealTextBoxBehavior), 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);
+
+    internal static readonly DependencyProperty PasswordBoxProperty = DependencyProperty.Register(
+        nameof(PasswordBox), typeof(PasswordBox), typeof(PasswordBoxRevealTextBoxBehavior), new PropertyMetadata(default(PasswordBox)));
+
+    internal PasswordBox? PasswordBox
+    {
+        get => (PasswordBox) GetValue(PasswordBoxProperty);
+        set => SetValue(PasswordBoxProperty, value);
+    }
+
+    private static PropertyInfo SelectionPropertyInfo { get; }
+    private static MethodInfo SelectMethodInfo { get; }
+    private static MethodInfo GetStartMethodInfo { get; }
+    private static MethodInfo GetEndMethodInfo { get; }
+    private static PropertyInfo GetOffsetPropertyInfo { get; }
+
+    static PasswordBoxRevealTextBoxBehavior()
+    {
+        SelectionPropertyInfo = typeof(PasswordBox).GetProperty("Selection", BindingFlags.NonPublic | BindingFlags.Instance) ?? throw new InvalidOperationException("Did not find 'Selection' property on PasswordBox");
+        SelectMethodInfo = typeof(PasswordBox).GetMethod("Select", BindingFlags.Instance | BindingFlags.NonPublic) ?? throw new InvalidOperationException("Did not find 'Select' method on PasswordBox");
+        Type iTextRange = typeof(PasswordBox).Assembly.GetType("System.Windows.Documents.ITextRange") ?? throw new InvalidOperationException("Failed to find ITextRange");
+        GetStartMethodInfo = iTextRange.GetProperty("Start")?.GetGetMethod() ?? throw new InvalidOperationException($"Failed to find 'Start' property on {iTextRange.FullName}");
+        GetEndMethodInfo = iTextRange.GetProperty("End")?.GetGetMethod() ?? throw new InvalidOperationException($"Failed to find 'End' property on {iTextRange.FullName}");
+        Type passwordTextPointer = typeof(PasswordBox).Assembly.GetType("System.Windows.Controls.PasswordTextPointer") ?? throw new InvalidOperationException("Failed to find PasswordTextPointer");
+        GetOffsetPropertyInfo = passwordTextPointer.GetProperty("Offset", BindingFlags.NonPublic | BindingFlags.Instance) ?? throw new InvalidOperationException("Failed to find 'Offset' property on PasswordTextPointer");
+    }
+
+    protected override void OnAttached()
+    {
+        base.OnAttached();
+        AssociatedObject.IsVisibleChanged += AssociatedObjectOnIsVisibleChanged;
+        if (PasswordBox != null)
+        {
+            var selection = SelectionPropertyInfo.GetValue(PasswordBox, null) as TextSelection;
+            SetSelection(AssociatedObject, selection);
+        }
+    }
+
+    protected override void OnDetaching()
+    {
+        base.OnDetaching();
+        if (AssociatedObject != null)
+        {
+            AssociatedObject.ClearValue(SelectionProperty);
+            AssociatedObject.IsVisibleChanged -= AssociatedObjectOnIsVisibleChanged;
+        }
+    }
+
+    private void AssociatedObjectOnIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
+    {
+        if (AssociatedObject.IsVisible)
+        {
+            AssociatedObject.SelectionLength = 0;
+            var selection = GetPasswordBoxSelection();
+            AssociatedObject.SelectionStart = selection.SelectionStart;
+            AssociatedObject.SelectionLength = selection.SelectionEnd;
+            Keyboard.Focus(AssociatedObject);
+        }
+        else if (PasswordBox != null)
+        {
+            SetPasswordBoxSelection(AssociatedObject.SelectionStart, AssociatedObject.SelectionLength);
+            Keyboard.Focus(PasswordBox);
+        }
+    }
+
+    private PasswordBoxSelection GetPasswordBoxSelection()
+    {
+        var selection = GetSelection(AssociatedObject);
+        object? start = GetStartMethodInfo.Invoke(selection, null);
+        object? end = GetEndMethodInfo.Invoke(selection, null);
+        int? startValue = GetOffsetPropertyInfo.GetValue(start, null) as int?;
+        int? endValue = GetOffsetPropertyInfo.GetValue(end, null) as int?;
+        int selectionStart = startValue ?? 0;
+        int selectionLength = 0;
+        if (endValue.HasValue)
+        {
+            selectionLength = endValue.Value - selectionStart;
+        }
+        return new PasswordBoxSelection(selectionStart, selectionLength);
+    }
+
+    private void SetPasswordBoxSelection(int selectionStart, int selectionLength) => SelectMethodInfo.Invoke(PasswordBox, new object[] { selectionStart, selectionLength });
+
+    private record struct PasswordBoxSelection(int SelectionStart, int SelectionEnd);
+}