public IObservable<IObservedChange<object, object>> GetNotificationForProperty(object sender, System.Linq.Expressions.Expression expression, bool beforeChanged = false)
{
Contract.Requires(sender != null && sender is DependencyObject);
var type = sender.GetType();
var propertyName = expression.GetMemberInfo().Name;
var depSender = sender as DependencyObject;
if (depSender == null)
{
this.Log().Warn("Tried to bind DP on a non-DependencyObject. Binding as POCO object",
type.FullName, propertyName);
var ret = new POCOObservableForProperty();
return ret.GetNotificationForProperty(sender, expression, beforeChanged);
}
if (beforeChanged == true) {
this.Log().Warn("Tried to bind DO {0}.{1}, but DPs can't do beforeChanged. Binding as POCO object",
type.FullName, propertyName);
var ret = new POCOObservableForProperty();
return ret.GetNotificationForProperty(sender, expression, beforeChanged);
}
var dpFetcher = getDependencyPropertyFetcher(type, propertyName);
if (dpFetcher == null) {
this.Log().Warn("Tried to bind DO {0}.{1}, but DP doesn't exist. Binding as POCO object",
type.FullName, propertyName);
var ret = new POCOObservableForProperty();
return ret.GetNotificationForProperty(sender, expression, beforeChanged);
}
#if WINDOWS_UWP
return Observable.Create<IObservedChange<object, object>>(subj => {
var handler = new DependencyPropertyChangedCallback((o, e) => {
subj.OnNext(new ObservedChange<object, object>(sender, expression));
});
var dependencyProperty = dpFetcher();
var token = depSender.RegisterPropertyChangedCallback(dependencyProperty, handler);
return Disposable.Create(() => depSender.UnregisterPropertyChangedCallback(dependencyProperty, token));
});
#else
var dpAndSubj = createAttachedProperty(type, propertyName);
return Observable.Create<IObservedChange<object, object>>(obs => {
BindingOperations.SetBinding(depSender, dpAndSubj.Item1,
new Binding() { Source = depSender, Path = new PropertyPath(propertyName) });
var disp = dpAndSubj.Item2
.Where(x => x == sender)
.Select(x => new ObservedChange<object, object>(x, expression))
.Subscribe(obs);
// ClearBinding calls ClearValue http://stackoverflow.com/questions/1639219/clear-binding-in-silverlight-remove-data-binding-from-setbinding
return new CompositeDisposable(Disposable.Create(() => depSender.ClearValue(dpAndSubj.Item1)), disp);
});
#endif
}
public IObservable<IObservedChange<object, object>> GetNotificationForProperty(object sender, System.Linq.Expressions.Expression expression, bool beforeChanged = false)
{
var type = sender.GetType();
var propertyName = expression.GetMemberInfo().Name;
var dpd = DependencyPropertyDescriptor.FromProperty(getDependencyProperty(type, propertyName), type);
return Observable.Create<IObservedChange<object, object>>(subj => {
var handler = new EventHandler((o, e) => {
subj.OnNext(new ObservedChange<object, object>(sender, expression));
});
dpd.AddValueChanged(sender, handler);
return Disposable.Create(() => dpd.RemoveValueChanged(sender, handler));
});
}
public IObservable<IObservedChange<object, object>> GetNotificationForProperty(object sender, System.Linq.Expressions.Expression expression, bool beforeChanged = false)
{
var type = sender.GetType();
var propertyName = expression.GetMemberInfo().Name;
var dpd = DependencyPropertyDescriptor.FromProperty(getDependencyProperty(type, propertyName), type);
if (dpd == null) {
this.Log().Error("Couldn't find dependency property " + propertyName + " on " + type.Name);
throw new NullReferenceException("Couldn't find dependency property " + propertyName + " on " + type.Name);
}
return Observable.Create<IObservedChange<object, object>>(subj => {
var handler = new EventHandler((o, e) => {
subj.OnNext(new ObservedChange<object, object>(sender, expression));
});
dpd.AddValueChanged(sender, handler);
return Disposable.Create(() => dpd.RemoveValueChanged(sender, handler));
});
}
