private void OnDataContextPropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (_subObservers.ContainsKey(e.PropertyName))
{
var propInfo = _dataContext != null && _propInfoCache.ContainsKey(e.PropertyName) ? _propInfoCache[e.PropertyName] : null;
var dataContext = _dataContext != null && propInfo.CanRead ? propInfo.GetValue(_dataContext, null) : null;
_subObservers[e.PropertyName].DataContext = dataContext;
}
if (!_nameRefs.ContainsKey(e.PropertyName))
{
// do not raise events for non-registered path (sub observer will do it)
return;
}
var handler = PropertyChanged;
if (handler != null && _nameRefs.ContainsKey(e.PropertyName))
{
var propInfo = _dataContext != null && _propInfoCache.ContainsKey(e.PropertyName) ? _propInfoCache[e.PropertyName] : null;
var args = new ObserverPropertyChangedEventArgs(
e.PropertyName,
DataContext,
propInfo);
handler(this, args);
}
}
private void Observer_OnPropertyChanged(object sender, ObserverPropertyChangedEventArgs e)
{
_targetBindings
.SelectMany(pair => pair.Value.Select(arg => new { Target = pair.Key, Binding = arg, }))
.Where(arg => arg.Binding.SourcePath == e.Path)
.ToList()
.ForEach(arg => UpdateTarget(arg.Target, arg.Binding));
}
private void SubObserver_OnPropertyChanged(object sender, ObserverPropertyChangedEventArgs e)
{
var handler = PropertyChanged;
if (handler != null)
{
var subObserver = sender as BindingObserver;
var args = new ObserverPropertyChangedEventArgs(
subObserver.Name + "." + e.Path,
e.DataContext,
e.PropertyInfo);
handler(this, args);
}
}
public void Register(string path)
{
var name = path;
var subName = string.Empty;
var dotIndex = path.IndexOf('.');
if (dotIndex >= 0)
{
name = path.Substring(0, dotIndex);
var subPos = dotIndex + 1;
subName = path.Substring(subPos, path.Length - subPos);
}
if (subName.Length > 0)
{
if (!_subObservers.ContainsKey(name))
{
OnCacheAdd(name);
var subObserver = new BindingObserver();
subObserver.Name = name;
var propInfo = _dataContext != null && _propInfoCache.ContainsKey(name) ? _propInfoCache[name] : null;
var dataContext = _dataContext != null && propInfo.CanRead ? propInfo.GetValue(_dataContext, null) : null;
subObserver.DataContext = _dataContext != null && propInfo.CanRead ? propInfo.GetValue(_dataContext, null) : null;
subObserver.PropertyChanged += SubObserver_OnPropertyChanged;
_subObservers[name] = subObserver;
}
_subObservers[name].Register(subName);
}
else
{
if (!_nameRefs.ContainsKey(name))
{
_nameRefs[name] = 0;
}
_nameRefs[name]++;
OnCacheAdd(name);
// init
var handler = PropertyChanged;
if (handler != null)
{
var args = new ObserverPropertyChangedEventArgs(name, DataContext, GetProperty(name));
handler(this, args);
}
}
}
