inabox/InABox.Avalonia/Navigation/Navigation.cs

using System;
using System.Diagnostics.Tracing;
using DialogHostAvalonia;
using InABox.Avalonia.Components;
using InABox.Avalonia.Router;

namespace InABox.Avalonia;


public interface IViewModelBase
{
    Task Activate();
    Task Deactivate();
    bool BackButtonVisible { get; set; }
    AvaloniaMenuItemCollection PrimaryMenu { get; set; }
    AvaloniaMenuItemCollection SecondaryMenu { get; set; }
}

public interface IPopupViewModel
{
    bool IsClosed { get; }
}

public interface IPopupViewModel<TResult> : IPopupViewModel
{
    TResult? GetResult();
}

public static class Navigation
{
    private static readonly HistoryRouter<IViewModelBase> _router;

    static Navigation()
    {
        _router = new HistoryRouter<IViewModelBase>(x => Activator.CreateInstance(x) as IViewModelBase);
        _router.CurrentViewModelChanging += (@base, direction) => CurrentViewModelChanging?.Invoke(@base, direction);
        _router.CurrentViewModelChanged += @base => CurrentViewModelChanged?.Invoke(@base);
    }

    public static void Back()
    {
        _router.Back();
    }

    public static void Navigate<T>(Action<T>? configure = null) where T : IViewModelBase
    {
        _router.GoTo<T>(configure);
    }

    public static async Task<object?> Popup<T>(Action<T>? configure = null, bool canTapAway = true)
        where T : IViewModelBase, IPopupViewModel
    {
        var viewModel = _router.InstantiateViewModel<T>(configure);
        return await Popup(viewModel, canTapAway);
    }

    public static async Task<object?> Popup<T>(T viewModel, bool canTapAway = true)
        where T : IViewModelBase, IPopupViewModel
    {
        await viewModel.Activate();
        var _result = await DialogHostAvalonia.DialogHost.Show(viewModel, (object sender, DialogClosingEventArgs eventArgs) =>
        {
            if(!canTapAway && !viewModel.IsClosed)
            {
                eventArgs.Cancel();
            }
        });
        await viewModel.Deactivate();
        return _result;
    }

    public static async Task<TResult?> Popup<T, TResult>(Action<T>? configure = null, bool canTapAway = true)
        where T : IViewModelBase, IPopupViewModel<TResult>
    {
        var viewModel = _router.InstantiateViewModel<T>(configure);
        return await Popup<T, TResult>(viewModel, canTapAway);
    }

    public static async Task<TResult?> Popup<T, TResult>(T viewModel, bool canTapAway = true)
        where T : IViewModelBase, IPopupViewModel<TResult>
    {
        await viewModel.Activate();
        var _result = await DialogHostAvalonia.DialogHost.Show(viewModel, (object sender, DialogClosingEventArgs eventArgs) =>
        {
            if(!canTapAway && !viewModel.IsClosed)
            {
                eventArgs.Cancel();
            }
        });
        await viewModel.Deactivate();
        return viewModel.GetResult();
    }

    public static void Reset<T>(Action<T>? configure = null) where T : IViewModelBase
    {
        _router.Reset<T>(configure);
    }

    public static event Action<IViewModelBase, RouterDirection>? CurrentViewModelChanging;

    public static event Action<IViewModelBase>? CurrentViewModelChanged;
}