ShrlAlgoToolkit/WPFluent/Controls/BitmapIcon/BitmapIcon.cs

using WPFluent.Controls.Primitives;

using System;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;

using System.Windows.Shapes;

namespace WPFluent.Controls;

/// <summary>
/// Represents an icon that uses a bitmap as its content.
/// </summary>
public class BitmapIcon : IconElementEx
{
    static BitmapIcon()
    {
        ForegroundProperty.OverrideMetadata(typeof(BitmapIcon), new FrameworkPropertyMetadata(OnForegroundChanged));
    }

    /// <summary>
    /// Initializes a new instance of the BitmapIcon class.
    /// </summary>
    public BitmapIcon()
    {
    }

    /// <summary>
    /// Identifies the UriSource dependency property.
    /// </summary>
    public static readonly DependencyProperty UriSourceProperty =
        BitmapImage.UriSourceProperty.AddOwner(
            typeof(BitmapIcon),
            new FrameworkPropertyMetadata(OnUriSourceChanged));

    /// <summary>
    /// Gets or sets the Uniform Resource Identifier (URI) of the bitmap to use as the
    /// icon content.
    /// </summary>
    /// <returns>The Uri of the bitmap to use as the icon content. The default is **null**.</returns>
    public Uri UriSource
    {
        get => (Uri)GetValue(UriSourceProperty);
        set => SetValue(UriSourceProperty, value);
    }

    private static void OnUriSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((BitmapIcon)d).ApplyUriSource();
    }

    /// <summary>
    /// Identifies the ShowAsMonochrome dependency property.
    /// </summary>
    public static readonly DependencyProperty ShowAsMonochromeProperty =
        DependencyProperty.Register(
            nameof(ShowAsMonochrome),
            typeof(bool),
            typeof(BitmapIcon),
            new PropertyMetadata(true, OnShowAsMonochromeChanged));

    /// <summary>
    /// Gets or sets a value that indicates whether the bitmap is shown in a single color.
    /// </summary>
    /// <returns>
    /// **true** to show the bitmap in a single color; **false** to show the bitmap in
    /// full color. The default is **true.**
    /// </returns>
    public bool ShowAsMonochrome
    {
        get => (bool)GetValue(ShowAsMonochromeProperty);
        set => SetValue(ShowAsMonochromeProperty, value);
    }

    private static void OnShowAsMonochromeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((BitmapIcon)d).ApplyShowAsMonochrome();
    }

    protected override UIElement InitializeChildren()
    {
        _image = new Image
        {
            Visibility = Visibility.Hidden
        };

        _opacityMask = new ImageBrush();
        _foreground = new Rectangle
        {
            OpacityMask = _opacityMask
        };

        ApplyForeground();
        ApplyUriSource();

        Children.Add(_image);

        ApplyShowAsMonochrome();

        return _image;
    }

    private protected override void OnShouldInheritForegroundFromVisualParentChanged()
    {
        ApplyForeground();
    }

    private protected override void OnVisualParentForegroundPropertyChanged(DependencyPropertyChangedEventArgs args)
    {
        if (ShouldInheritForegroundFromVisualParent)
        {
            ApplyForeground();
        }
    }

    private static void OnForegroundChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((BitmapIcon)d).ApplyForeground();
    }

    private void ApplyForeground()
    {
        if (_foreground != null)
        {
            _foreground.Fill = ShouldInheritForegroundFromVisualParent ? VisualParentForeground : Foreground;
        }
    }

    private void ApplyUriSource()
    {
        if (_image != null && _opacityMask != null)
        {
            var uriSource = UriSource;
            if (uriSource != null)
            {
                var imageSource = new BitmapImage(uriSource);
                _image.Source = imageSource;
                _opacityMask.ImageSource = imageSource;
            }
            else
            {
                _image.ClearValue(Image.SourceProperty);
                _opacityMask.ClearValue(ImageBrush.ImageSourceProperty);
            }
        }
    }

    private void ApplyShowAsMonochrome()
    {
        bool showAsMonochrome = ShowAsMonochrome;

        if (_image != null)
        {
            _image.Visibility = showAsMonochrome ? Visibility.Hidden : Visibility.Visible;
        }

        if (_foreground != null)
        {
            if (showAsMonochrome)
            {
                if (!Children.Contains(_foreground))
                {
                    Children.Add(_foreground);
                }
            }
            else
            {
                Children.Remove(_foreground);
            }
        }
    }

    private Image _image = null!;
    private Rectangle _foreground = null!;
    private ImageBrush _opacityMask = null!;
}