protected override void OnPropertyChanged(string propertyName)
{
IModelTreeItem modelTreeItem = (IModelTreeItem)this;
ModelItem currentValue;
//if property value has changed - remove existing value, so the ModelPropertyImplementation will
//force reading the value from the underlying object
if (modelTreeItem.ModelPropertyStore.TryGetValue(propertyName, out currentValue))
{
IModelTreeItem valueAsTreeItem = (IModelTreeItem)currentValue;
//cleanup references
valueAsTreeItem.RemoveParent(this);
valueAsTreeItem.RemoveSource(this.Properties[propertyName]);
//remove from store
modelTreeItem.ModelPropertyStore.Remove(propertyName);
}
base.OnPropertyChanged(propertyName);
}
public override ModelItem SetValue(object value)
{
//are we already setting value?
if (!isSettingValue)
{
try
{
this.isSettingValue = true;
//create new value
this.temporaryValue = this.WrapValue(value);
//is there a value stored already?
if (this.parentModelTreeItem.ModelPropertyStore.ContainsKey(this.Name))
{
//yes - cleanup references
IModelTreeItem item = (IModelTreeItem)this.parentModelTreeItem.ModelPropertyStore[this.Name];
item.RemoveSource(this);
item.RemoveParent(this.parentModelTreeItem.ModelItem);
//and remove it
this.parentModelTreeItem.ModelPropertyStore.Remove(this.Name);
}
//set it onto underlying object
this.PropertyDescriptor.SetValue(this.Parent.GetCurrentValue(), (null != this.temporaryValue ? this.temporaryValue.GetCurrentValue() : null));
//store it in parent's store
this.temporaryValue = this.StoreValue(this.temporaryValue);
//notify listeners - notification must be postponed until actual underlying object value is updated, otherwise, listeners might get old value
this.parentModelTreeItem.ModelTreeManager.AddToCurrentEditingScope(new FakeModelNotifyPropertyChange(this.parentModelTreeItem, this.Name));
}
catch (ValidationException e)
{
Trace.WriteLine(e.ToString());
//it is important to rethrow exception here - otherwise, DataGrid will assume operation completed successfully
throw;
}
finally
{
this.isSettingValue = false;
}
}
return(this.temporaryValue);
}
FakeModelItemImpl StoreValue(object value)
{
FakeModelItemImpl wrappedValue = WrapValue(value);
if (null != wrappedValue)
{
this.parentModelTreeItem.ModelPropertyStore[this.Name] = wrappedValue;
IModelTreeItem modelTreeItem = (IModelTreeItem)wrappedValue;
modelTreeItem.SetSource(this);
}
else
{
ModelItem existing = null;
if (this.parentModelTreeItem.ModelPropertyStore.TryGetValue(this.Name, out existing))
{
IModelTreeItem modelTreeItem = (IModelTreeItem)existing;
modelTreeItem.RemoveSource(this);
modelTreeItem.RemoveParent(this.Parent);
}
this.parentModelTreeItem.ModelPropertyStore.Remove(this.Name);
}
return(wrappedValue);
}
