Shrlalgo.RvKits/WPFluent/Controls/PasswordBox/PasswordBox.cs




// TODO: This is an initial implementation and requires the necessary corrections, tests and adjustments.

/* TextProperty contains asterisks OR raw password if IsPasswordRevealed is set to true
   PasswordProperty always contains raw password */


using System.Windows.Controls;

// ReSharper disable once CheckNamespace
namespace WPFluent.Controls;

/// <summary>
/// The modified password control.
/// </summary>
public partial class PasswordBox : WPFluent.Controls.TextBox
{
    /// <summary>
    /// Identifies the <see cref="IsPasswordRevealed"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty IsPasswordRevealedProperty = DependencyProperty.Register(
        nameof(IsPasswordRevealed),
        typeof(bool),
        typeof(PasswordBox),
        new PropertyMetadata(false, OnIsPasswordRevealedChanged));

    /// <summary>
    /// Identifies the <see cref="PasswordChanged"/> routed event.
    /// </summary>
    public static readonly RoutedEvent PasswordChangedEvent = EventManager.RegisterRoutedEvent(
        nameof(PasswordChanged),
        RoutingStrategy.Bubble,
        typeof(RoutedEventHandler),
        typeof(PasswordBox));

    /// <summary>
    /// Identifies the <see cref="PasswordChar"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty PasswordCharProperty = DependencyProperty.Register(
        nameof(PasswordChar),
        typeof(char),
        typeof(PasswordBox),
        new PropertyMetadata('*', OnPasswordCharChanged));

    /// <summary>
    /// Identifies the <see cref="Password"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty PasswordProperty = DependencyProperty.Register(
        nameof(Password),
        typeof(string),
        typeof(PasswordBox),
        new PropertyMetadata(string.Empty, OnPasswordChanged));

    /// <summary>
    /// Identifies the <see cref="RevealButtonEnabled"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty RevealButtonEnabledProperty = DependencyProperty.Register(
        nameof(RevealButtonEnabled),
        typeof(bool),
        typeof(PasswordBox),
        new PropertyMetadata(true));
    private bool _lockUpdatingContents;
    private readonly PasswordHelper _passwordHelper;

    public PasswordBox()
    {
        _lockUpdatingContents = false;
        _passwordHelper = new PasswordHelper(this);
    }

    /// <summary>
    /// Event fired from this text box when its inner content has been changed.
    /// </summary>
    /// <remarks>
    /// It is redirected from inner TextContainer.Changed event.
    /// </remarks>
    public event RoutedEventHandler PasswordChanged
    {
        add => AddHandler(PasswordChangedEvent, value);
        remove => RemoveHandler(PasswordChangedEvent, value);
    }

    /// <summary>
    /// Called if the reveal mode is changed in the during the run.
    /// </summary>
    private static void OnIsPasswordRevealedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if(d is not PasswordBox control)
        {
            return;
        }

        control.OnPasswordRevealModeChanged();
    }

    /// <summary>
    /// Called when <see cref="Password"/> is changed.
    /// </summary>
    private static void OnPasswordChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if(d is not PasswordBox control)
        {
            return;
        }

        control.OnPasswordChanged();
    }

    /// <summary>
    /// Called if the character is changed in the during the run.
    /// </summary>
    private static void OnPasswordCharChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if(d is not PasswordBox control)
        {
            return;
        }

        control.OnPasswordCharChanged();
    }

    private void UpdateTextContents(bool isTriggeredByTextInput)
    {
        if(_lockUpdatingContents)
        {
            return;
        }

        if(IsPasswordRevealed)
        {
            if(Password == Text)
            {
                return;
            }

            _lockUpdatingContents = true;

            if(isTriggeredByTextInput)
            {
                SetCurrentValue(PasswordProperty, Text);
            }
            else
            {
                SetCurrentValue(TextProperty, Password);
                CaretIndex = Text.Length;
            }

            RaiseEvent(new RoutedEventArgs(PasswordChangedEvent));

            _lockUpdatingContents = false;

            return;
        }

        var caretIndex = CaretIndex;
        var newPasswordValue = _passwordHelper.GetPassword();

        if(isTriggeredByTextInput)
        {
            newPasswordValue = _passwordHelper.GetNewPassword();
        }

        _lockUpdatingContents = true;

        SetCurrentValue(TextProperty, new string(PasswordChar, newPasswordValue.Length));
        SetCurrentValue(PasswordProperty, newPasswordValue);
        CaretIndex = caretIndex;

        RaiseEvent(new RoutedEventArgs(PasswordChangedEvent));

        _lockUpdatingContents = false;
    }

    /// <summary>
    /// Is called when <see cref="Password"/> property is changing.
    /// </summary>
    protected virtual void OnPasswordChanged() { UpdateTextContents(false); }

    /// <summary>
    /// Is called when <see cref="PasswordChar"/> property is changing.
    /// </summary>
    protected virtual void OnPasswordCharChanged()
    {
        // If password is currently revealed,
        // do not replace displayed text with asterisks
        if(IsPasswordRevealed)
        {
            return;
        }

        _lockUpdatingContents = true;

        SetCurrentValue(TextProperty, new string(PasswordChar, Password.Length));

        _lockUpdatingContents = false;
    }

    protected virtual void OnPasswordRevealModeChanged()
    {
        _lockUpdatingContents = true;

        SetCurrentValue(TextProperty, IsPasswordRevealed ? Password : new string(PasswordChar, Password.Length));

        _lockUpdatingContents = false;
    }

    /// <summary>
    /// Triggered by clicking a button in the control template.
    /// </summary>
    /// <param name="parameter">Additional parameters.</param>
    protected override void OnTemplateButtonClick(string? parameter)
    {
        System.Diagnostics.Debug
            .WriteLine(
                $"INFO: {typeof(PasswordBox)} button clicked with param: {parameter}",
                "WPFluent.PasswordBox");

        switch(parameter)
        {
            case "reveal":
                SetCurrentValue(IsPasswordRevealedProperty, !IsPasswordRevealed);
                Focus();
                CaretIndex = Text.Length;
                break;
            default:
                base.OnTemplateButtonClick(parameter);
                break;
        }
    }

    /// <inheritdoc/>
    protected override void OnTextChanged(TextChangedEventArgs e)
    {
        UpdateTextContents(true);

        if(_lockUpdatingContents)
        {
            base.OnTextChanged(e);
        }
        else
        {
            SetPlaceholderTextVisibility();

            RevealClearButton();
        }
    }

    /// <summary>
    /// Gets a value indicating whether the password is revealed.
    /// </summary>
    public bool IsPasswordRevealed
    {
        get => (bool)GetValue(IsPasswordRevealedProperty);
        private set => SetValue(IsPasswordRevealedProperty, value);
    }

    /// <summary>
    /// Gets or sets currently typed text represented by asterisks.
    /// </summary>
    public string Password { get => (string)GetValue(PasswordProperty); set => SetValue(PasswordProperty, value); }

    /// <summary>
    /// Gets or sets character used to mask the password.
    /// </summary>
    public char PasswordChar
    {
        get => (char)GetValue(PasswordCharProperty);
        set => SetValue(PasswordCharProperty, value);
    }

    /// <summary>
    /// Gets or sets a value indicating whether to display the password reveal button.
    /// </summary>
    public bool RevealButtonEnabled
    {
        get => (bool)GetValue(RevealButtonEnabledProperty);
        set => SetValue(RevealButtonEnabledProperty, value);
    }
}