Files
FileTime2/src/AppCommon/FileTime.App.Core/Services/UserCommandHandler/UserCommandHandlerServiceBase.cs

74 lines
3.2 KiB
C#

using System.Collections.ObjectModel;
using System.Reactive.Linq;
using DeclarativeProperty;
using DynamicData;
using FileTime.App.Core.ViewModels;
using FileTime.Core.Models;
using FileTime.Core.Timeline;
namespace FileTime.App.Core.Services.UserCommandHandler;
public abstract class UserCommandHandlerServiceBase : IUserCommandHandler
{
private readonly List<IUserCommandHandler> _userCommandHandlers = new();
private readonly IAppState? _appState;
private readonly ITimelessContentProvider? _timelessContentProvider;
protected UserCommandHandlerServiceBase(
IAppState? appState = null,
ITimelessContentProvider? timelessContentProvider = null)
{
_appState = appState;
_timelessContentProvider = timelessContentProvider;
}
public bool CanHandleCommand(UserCommand.IUserCommand command) => _userCommandHandlers.Any(h => h.CanHandleCommand(command));
public async Task HandleCommandAsync(UserCommand.IUserCommand command)
{
var handler = _userCommandHandlers.Find(h => h.CanHandleCommand(command));
if (handler is null) return;
await handler.HandleCommandAsync(command);
}
protected void AddCommandHandler(IUserCommandHandler userCommandHandler) => _userCommandHandlers.Add(userCommandHandler);
protected void AddCommandHandlers(IEnumerable<IUserCommandHandler> commandHandlers)
{
foreach (var userCommandHandler in commandHandlers)
{
AddCommandHandler(userCommandHandler);
}
}
protected void RemoveCommandHandler(IUserCommandHandler userCommandHandler) => _userCommandHandlers.Remove(userCommandHandler);
protected IDisposable SaveSelectedTab(Action<ITabViewModel?> handler) => RunWithAppState(appState => appState.SelectedTab.Subscribe(handler));
protected IDisposable SaveCurrentSelectedItem(Action<IDeclarativeProperty<IItemViewModel?>?> handler)
=> RunWithAppState(appState => appState.SelectedTab.Select(t => t?.CurrentSelectedItem).Subscribe(handler));
protected IDisposable SaveCurrentLocation(Action<IDeclarativeProperty<IContainer?>?> handler)
=> RunWithAppState(appState => appState.SelectedTab.Select(t => t?.CurrentLocation).Subscribe(handler));
protected IDisposable SaveCurrentItems(Action<IDeclarativeProperty<ObservableCollection<IItemViewModel>?>?> handler)
=> RunWithAppState(appState => appState.SelectedTab.Select(t => t?.CurrentItems).Subscribe(handler));
protected IDisposable SaveCurrentPointInTime(Action<PointInTime> handler)
=> RunWithTimelessContentProvider(timelessContentProvider => timelessContentProvider.CurrentPointInTime.Subscribe(handler));
private IDisposable RunWithAppState(Func<IAppState, IDisposable> act)
{
if (_appState == null) throw new NullReferenceException($"AppState is not initialized in {nameof(UserCommandHandlerServiceBase)}.");
return act(_appState);
}
private IDisposable RunWithTimelessContentProvider(Func<ITimelessContentProvider, IDisposable> act)
{
if (_timelessContentProvider == null) throw new NullReferenceException($"TimelessContainer is not initialized in {nameof(UserCommandHandlerServiceBase)}.");
return act(_timelessContentProvider);
}
}