Wino-Mail/Wino.Mail/Behaviors/BindableCommandBarBehavior.cs

using System.Collections;
using System.Collections.Specialized;
using System.Windows.Input;
using Microsoft.Xaml.Interactivity;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Wino.Controls;
using Wino.Core.Domain.Models.Menus;
using Wino.Core.UWP.Controls;
using Wino.Helpers;

namespace Wino.Behaviors;

public class BindableCommandBarBehavior : Behavior<CommandBar>
{
    public static readonly DependencyProperty PrimaryCommandsProperty = DependencyProperty.Register(
        "PrimaryCommands", typeof(object), typeof(BindableCommandBarBehavior),
        new PropertyMetadata(null, UpdateCommands));

    public ICommand ItemClickedCommand
    {
        get { return (ICommand)GetValue(ItemClickedCommandProperty); }
        set { SetValue(ItemClickedCommandProperty, value); }
    }

    public static readonly DependencyProperty ItemClickedCommandProperty = DependencyProperty.Register(nameof(ItemClickedCommand), typeof(ICommand), typeof(BindableCommandBarBehavior), new PropertyMetadata(null));

    public object PrimaryCommands
    {
        get { return GetValue(PrimaryCommandsProperty); }
        set { SetValue(PrimaryCommandsProperty, value); }
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();

        AttachChanges(false);

        if (PrimaryCommands is IEnumerable enumerable)
        {
            foreach (var item in enumerable)
            {
                if (item is ButtonBase button)
                {
                    button.Click -= Button_Click;
                }
            }
        }
    }

    private void UpdatePrimaryCommands()
    {
        if (AssociatedObject == null)
            return;

        if (PrimaryCommands == null)
            return;

        if (AssociatedObject.PrimaryCommands is IEnumerable enumerableObjects)
        {
            foreach (var item in enumerableObjects)
            {
                if (item is ButtonBase button)
                {
                    button.Click -= Button_Click;
                }
            }
        }

        if (AssociatedObject.SecondaryCommands is IEnumerable secondaryObject)
        {
            foreach (var item in secondaryObject)
            {
                if (item is ButtonBase button)
                {
                    button.Click -= Button_Click;
                }
            }
        }

        AssociatedObject.PrimaryCommands.Clear();
        AssociatedObject.SecondaryCommands.Clear();

        if (!(PrimaryCommands is IEnumerable enumerable)) return;

        foreach (var command in enumerable)
        {
            if (command is MailOperationMenuItem mailOperationMenuItem)
            {
                ICommandBarElement menuItem = null;

                if (mailOperationMenuItem.Operation == Core.Domain.Enums.MailOperation.Seperator)
                {
                    menuItem = new AppBarSeparator();
                }
                else
                {
                    var label = XamlHelpers.GetOperationString(mailOperationMenuItem.Operation);
                    menuItem = new AppBarButton
                    {
                        Icon = new WinoFontIcon() { Glyph = ControlConstants.WinoIconFontDictionary[XamlHelpers.GetWinoIconGlyph(mailOperationMenuItem.Operation)] },
                        Label = label,
                        LabelPosition = string.IsNullOrWhiteSpace(label) ? CommandBarLabelPosition.Collapsed : CommandBarLabelPosition.Default,
                        DataContext = mailOperationMenuItem,
                    };

                    ToolTip toolTip = new ToolTip
                    {
                        Content = label
                    };
                    ToolTipService.SetToolTip((DependencyObject)menuItem, toolTip);

                    ((AppBarButton)menuItem).Click -= Button_Click;
                    ((AppBarButton)menuItem).Click += Button_Click;
                }

                if (mailOperationMenuItem.IsSecondaryMenuPreferred)
                {
                    AssociatedObject.SecondaryCommands.Add(menuItem);
                }
                else
                {
                    AssociatedObject.PrimaryCommands.Add(menuItem);
                }
            }

            //if (dependencyObject is ICommandBarElement icommandBarElement)
            //{
            //    if (dependencyObject is ButtonBase button)
            //    {
            //        button.Click -= Button_Click;
            //        button.Click += Button_Click;
            //    }

            //    if (command is MailOperationMenuItem mailOperationMenuItem)
            //    {

            //    }
            //}
        }
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        ItemClickedCommand?.Execute(((ButtonBase)sender).DataContext);
    }

    protected override void OnAttached()
    {
        base.OnAttached();

        AttachChanges(true);

        UpdatePrimaryCommands();
    }

    private void PrimaryCommandsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        UpdatePrimaryCommands();
    }

    private static void UpdateCommands(DependencyObject dependencyObject,
        DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
    {
        if (!(dependencyObject is BindableCommandBarBehavior behavior)) return;

        if (dependencyPropertyChangedEventArgs.OldValue is INotifyCollectionChanged oldList)
        {
            oldList.CollectionChanged -= behavior.PrimaryCommandsCollectionChanged;
        }

        behavior.AttachChanges(true);
        behavior.UpdatePrimaryCommands();
    }

    private void AttachChanges(bool register)
    {
        if (PrimaryCommands is null) return;

        if (PrimaryCommands is INotifyCollectionChanged collectionChanged)
        {
            if (register)
            {
                collectionChanged.CollectionChanged -= PrimaryCommandsCollectionChanged;
                collectionChanged.CollectionChanged += PrimaryCommandsCollectionChanged;
            }
            else
                collectionChanged.CollectionChanged -= PrimaryCommandsCollectionChanged;
        }
    }
}