/// <inheritdoc/>
public IDisposable BindCommandToObject(ICommand command, object target, IObservable <object> commandParameter)
{
if (command == null)
{
throw new ArgumentNullException(nameof(command));
}
if (target == null)
{
throw new ArgumentNullException(nameof(target));
}
commandParameter = commandParameter ?? Observable.Return(target);
object latestParam = null;
var ctlDelegate = new ControlDelegate(
x =>
{
if (command.CanExecute(latestParam))
{
command.Execute(latestParam);
}
})
{
IsEnabled = command.CanExecute(latestParam)
};
var sel = new Selector("theAction:");
// TODO how does this work? Is there an Action property?
Reflection.GetValueSetterOrThrow(target.GetType().GetRuntimeProperty("Action"))(target, sel, null);
var targetSetter = Reflection.GetValueSetterOrThrow(target.GetType().GetRuntimeProperty("Target"));
targetSetter(target, ctlDelegate, null);
var actionDisp = Disposable.Create(() => targetSetter(target, null, null));
var enabledSetter = Reflection.GetValueSetterForProperty(target.GetType().GetRuntimeProperty("Enabled"));
if (enabledSetter == null)
{
return(actionDisp);
}
// initial enabled state
enabledSetter(target, command.CanExecute(latestParam), null);
var compDisp = new CompositeDisposable(
actionDisp,
commandParameter.Subscribe(x => latestParam = x),
Observable.FromEventPattern <EventHandler, EventArgs>(x => command.CanExecuteChanged += x, x => command.CanExecuteChanged -= x)
.Select(_ => command.CanExecute(latestParam))
.Subscribe(x =>
{
enabledSetter(target, x, null);
ctlDelegate.IsEnabled = x;
}));
return(compDisp);
}
private IDisposable BindToDirect <TTarget, TValue>(
IObservable <TValue> @this,
TTarget target,
Expression viewExpression)
where TTarget : class
{
var setter = Reflection.GetValueSetterOrThrow(viewExpression.GetMemberInfo());
if (viewExpression.GetParent().NodeType == ExpressionType.Parameter)
{
return(@this.Subscribe(
x => setter(target, x, viewExpression.GetArgumentsArray()),
ex =>
{
this.Log().ErrorException($"{viewExpression} Binding received an Exception!", ex);
}));
}
var bindInfo = Observable.CombineLatest(
@this,
target.WhenAnyDynamic(viewExpression.GetParent(), x => x.Value),
(val, host) => new { val, host });
return(bindInfo
.Where(x => x.host != null)
.Subscribe(
x => setter(x.host, x.val, viewExpression.GetArgumentsArray()),
ex =>
{
this.Log().ErrorException($"{viewExpression} Binding received an Exception!", ex);
}));
}
