internal static WeakReference GetNativeObjectWeakReference(NSObject nsObject)
{
var handle = nsObject.Handle;
if (handle == IntPtr.Zero)
{
return(Empty.WeakReference);
}
lock (AttachedValueHolders)
{
AttachedValueHolder value;
if (!AttachedValueHolders.TryGetValue(handle, out value))
{
value = new AttachedValueHolder(nsObject);
AttachedValueHolders[handle] = value;
}
return(value.WeakReference);
}
}
protected override LightDictionaryBase <string, object> GetOrAddAttachedDictionary(object item, bool addNew)
{
var model = item as NotifyPropertyChangedBase;
if (model != null)
{
return(AttachedValueProviderDefault.GetOrAddAttachedValues(model, true));
}
#if TOUCH
var nsObject = item as NSObject;
if (nsObject != null)
{
var handle = nsObject.Handle;
if (handle == IntPtr.Zero)
{
if (addNew)
{
Tracer.Error("The object {0} is disposed the attached values cannot be obtained", item.GetType());
return(new AttachedValueDictionary());
}
return(null);
}
AttachedValueHolder holder;
lock (AttachedValueHolders)
{
if (!AttachedValueHolders.TryGetValue(handle, out holder))
{
if (!addNew)
{
return(null);
}
holder = new AttachedValueHolder(nsObject);
AttachedValueHolders[handle] = holder;
}
}
return(holder.GetOrCreateDictionary());
}
#elif !WINFORMS && !NET_STANDARD && !ANDROID && !TOUCH && !XAMARIN_FORMS
//Synchronization is not necessary because accessing the DependencyObject is possible only from the main thread.
var dependencyObject = item as DependencyObject;
if (dependencyObject != null)
{
var dict = (AttachedValueDictionary)dependencyObject.GetValue(AttachedValueDictionaryProperty);
if (dict == null && addNew)
{
dict = new AttachedValueDictionary();
dependencyObject.SetValue(AttachedValueDictionaryProperty, dict);
}
return(dict);
}
#elif XAMARIN_FORMS
var bindableObject = item as BindableObject;
if (bindableObject != null)
{
var dict = (AttachedValueDictionary)bindableObject.GetValue(AttachedValueDictionaryProperty);
if (dict == null && addNew)
{
lock (_internalDictionary)
{
dict = (AttachedValueDictionary)bindableObject.GetValue(AttachedValueDictionaryProperty);
if (dict == null)
{
dict = new AttachedValueDictionary();
bindableObject.SetValue(AttachedValueDictionaryProperty, dict);
}
}
}
return(dict);
}
#elif ANDROID
if (SetTagSupported)
{
var view = item as View;
if (view.IsAlive())
{
var dict = (AttachedValueDictionaryJava)view.GetTag(Resource.Id.AttachedProperties);
if (dict == null && addNew)
{
lock (_internalDictionary)
{
dict = (AttachedValueDictionaryJava)view.GetTag(Resource.Id.AttachedProperties);
if (dict == null)
{
dict = new AttachedValueDictionaryJava();
view.SetTag(Resource.Id.AttachedProperties, dict);
}
}
}
return(dict?.Dictionary);
}
}
//.NET object (Preference) is garbage collected and all attached members too but Java object is still alive.
//Save values to activity dictionary.
var pref = item as Preference;
if (pref.IsAlive() && pref.HasKey)
{
try
{
var activityView = pref.Context as IActivityView;
if (activityView != null)
{
var metadata = activityView.Mediator.Metadata;
var key = pref.Key + pref.GetType().FullName + pref.GetHashCode();
object v;
if (!metadata.TryGetValue(key, out v))
{
if (addNew)
{
v = new AttachedValueDictionary();
metadata[key] = v;
}
}
return((LightDictionaryBase <string, object>)v);
}
}
catch
{
;
}
}
#endif
if (addNew)
{
return(_internalDictionary.GetValue(item, CreateDictionaryDelegate));
}
AttachedValueDictionary value;
_internalDictionary.TryGetValue(item, out value);
return(value);
}
protected override LightDictionaryBase <string, object> GetOrAddAttachedDictionary(object item, bool addNew)
{
var handler = GetOrAddAttachedDictionaryHandler?.GetInvocationList();
if (handler != null)
{
for (int i = 0; i < handler.Length; i++)
{
var result = ((Func <object, bool, LightDictionaryBase <string, object> >)handler[i]).Invoke(item, addNew);
if (result != null)
{
return(result);
}
}
}
var model = item as NotifyPropertyChangedBase;
if (model != null)
{
return(GetOrAddAttachedValues(model, true));
}
#if TOUCH
var nsObject = item as NSObject;
if (nsObject != null)
{
var handle = nsObject.Handle;
if (handle == IntPtr.Zero)
{
if (addNew)
{
Tracer.Error("The object {0} is disposed the attached values cannot be obtained", item.GetType());
return(new AttachedValueDictionary());
}
return(null);
}
AttachedValueHolder holder;
lock (AttachedValueHolders)
{
if (!AttachedValueHolders.TryGetValue(handle, out holder))
{
if (!addNew)
{
return(null);
}
holder = new AttachedValueHolder(nsObject);
AttachedValueHolders[handle] = holder;
}
}
return(holder.GetOrCreateDictionary());
}
#elif WINDOWS_UWP || WPF || WINFORMS
//Synchronization is not necessary because accessing the DependencyObject is possible only from the main thread.
var dependencyObject = item as DependencyObject;
if (dependencyObject != null)
{
var dict = (AttachedValueDictionary)dependencyObject.GetValue(AttachedValueDictionaryProperty);
if (dict == null && addNew)
{
dict = new AttachedValueDictionary();
dependencyObject.SetValue(AttachedValueDictionaryProperty, dict);
}
return(dict);
}
#elif XAMARIN_FORMS
var bindableObject = item as BindableObject;
if (bindableObject != null)
{
var dict = (AttachedValueDictionary)bindableObject.GetValue(AttachedValueDictionaryProperty);
if (dict == null && addNew)
{
lock (_internalDictionary)
{
dict = (AttachedValueDictionary)bindableObject.GetValue(AttachedValueDictionaryProperty);
if (dict == null)
{
dict = new AttachedValueDictionary();
bindableObject.SetValue(AttachedValueDictionaryProperty, dict);
}
}
}
return(dict);
}
#elif ANDROID
if (SetTagSupported)
{
var view = item as View;
if (view.IsAlive())
{
var dict = (AttachedValueDictionaryJava)view.GetTag(Resource.Id.AttachedProperties);
if (dict == null && addNew)
{
lock (_internalDictionary)
{
dict = (AttachedValueDictionaryJava)view.GetTag(Resource.Id.AttachedProperties);
if (dict == null)
{
dict = new AttachedValueDictionaryJava();
view.SetTag(Resource.Id.AttachedProperties, dict);
}
}
}
return(dict?.Dictionary);
}
}
#endif
if (addNew)
{
return(_internalDictionary.GetValue(item, CreateDictionaryDelegate));
}
AttachedValueDictionary value;
_internalDictionary.TryGetValue(item, out value);
return(value);
}
