/// <inheritdoc />
public async Task <bool> ComposeAsync(IViewCompositionContext context)
{
try
{
DataContextLoadedCompletion = new TaskCompletionSource <object>();
SetCoordinationArguments(context.Control, context.CoordinationArguments);
Log.Debug($"Composition is being configured.");
Configure(context);
Log.Debug($"Attaching DataContextChanged and Unload events.");
context.Control.DataContextChanged -= DataContextChanged;
context.Control.DataContextChanged += DataContextChanged;
// memory leak countermeasure
context.Control.Unloaded += ControlOnUnloaded;
Log.Debug($"Finalizing composition.");
await FinalizeCompositionAsync(context);
await BehaviorRunner.ExecuteAsync(context.DataContext as IBehaviorHost, new ViewComposedBehaviorContext(context, ServiceContext));
await DataContextLoadedCompletion.Task;
return(true);
}
catch (Exception e)
{
Log.Error(e);
return(false);
}
}
/// <inheritdoc />
protected override void Configure(IViewCompositionContext context)
{
if (context.Control is Window window)
{
if (context.DataContext is IWindowViewModel windowViewModel)
{
window.SizeToContent = windowViewModel.SizeToContent;
window.ShowInTaskbar = windowViewModel.ShowInTaskbar;
windowViewModel.WhenFocusRequested.Subscribe(o => window.Focus());
windowViewModel.WhenClosingRequested.Subscribe(o => window.Close());
windowViewModel.WhenMinimizeRequested.Subscribe(o => window.WindowState = WindowState.Minimized);
windowViewModel.WhenMaximizeRequested.Subscribe(o => window.WindowState = WindowState.Maximized);
windowViewModel.WhenNormalizeRequested.Subscribe(o => window.WindowState = WindowState.Normal);
window.WhenClosing().Subscribe(args =>
{
if (windowViewModel is IWindowListener listener)
{
listener.NotifyClosing(args);
}
});
window.WhenStateChanged().Throttle(TimeSpan.FromMilliseconds(50)).Subscribe(args =>
{
if (windowViewModel is IWindowListener listener)
{
listener.NotifyWindowStateChange(args);
}
});
window.WhenLocationChanged().Throttle(TimeSpan.FromMilliseconds(50)).Subscribe(args =>
{
if (windowViewModel is IWindowListener listener)
{
listener.NotifyLocationChanged(args);
}
});
window.WhenSizeChanged().Throttle(TimeSpan.FromMilliseconds(50)).Subscribe(args =>
{
if (windowViewModel is IWindowListener listener)
{
listener.NotifySizeChanged(args);
}
});
window.WhenClosed().Subscribe(async(args) =>
{
if (windowViewModel is IWindowListener listener)
{
listener.NotifyClosed();
}
await BehaviorRunner.ExecuteAsync(windowViewModel as IBehaviorHost, new WindowClosedContext(windowViewModel, ServiceContext.ServiceProvider, context));
});
}
}
}
private async void DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
try
{
if (sender is FrameworkElement element)
{
Log.Debug($"DataContext has changed.");
element.DataContextChanged -= DataContextChanged;
if (element.DataContext is IServiceProviderHolder holder)
{
Log.Debug($"ServiceProvider set through {nameof(IServiceProviderHolder)}.");
holder.ServiceProvider = ServiceContext.ServiceProvider;
}
if (element.DataContext is IWindowViewModel windowViewModel)
{
if (windowViewModel.Content is IServiceProviderHolder subHolder)
{
subHolder.ServiceProvider = ServiceContext.ServiceProvider;
}
}
if (element.DataContext is IDefaultBehaviorProvider behaviourProvider && element.DataContext is IBehaviorHost interactiveBehaviour)
{
var behaviours = behaviourProvider.GetDefaultBehaviors().ToArray();
if (behaviours.Length > 0)
{
Log.Debug($"Binding {behaviours.Length} behaviours through {nameof(IDefaultBehaviorProvider)} [{string.Join(".", behaviours.Select(s => s.GetType().ToString()))}].");
}
interactiveBehaviour.Behaviors.AddRange(behaviours);
}
foreach (var hook in ComposerHooks)
{
Log.Debug($"Executing [{nameof(IViewComposerHook)}] -> [{hook.GetType().ToString()}]");
hook.Execute(element, element.DataContext);
}
await BehaviorRunner.ExecuteAsync(element.DataContext as IBehaviorHost, new ActivationBehaviorContext(element.DataContext, ServiceContext.ServiceProvider));
var coordinationArguments = GetCoordinationArguments(element);
if (element.DataContext is ICompositionListener listener)
{
listener.Execute(new ViewCompositionContext(element, element.DataContext, coordinationArguments));
}
DataContextLoaded(new ViewCompositionContext(element, element.DataContext, coordinationArguments));
}
DataContextLoadedCompletion.TrySetResult(true);
}
catch (Exception exception)
{
DataContextLoadedCompletion.TrySetException(exception);
}
}