Rocky Change Request - EditableRootListBase<T>

FireGarden posted on Thursday, July 05, 2007

private void Child_PropertyChanged(object sender, PropertyChangedEventArgs e) { for (int index = 0; index < base.Count; index++) { if (object.ReferenceEquals(base[index], sender)) { this.OnListChanged(new ListChangedEventArgs(ListChangedType.ItemChanged, index)); break; } } }

Rocky,
I am working with an EditableRootList using an Object implementing INotifyPropertyChanged.

EditableRootList listens for children INotify events and forwards the call to a list changed event.

Unfortunately I too would like to know about the root child's INotify event. I could hookup an event handler however it would be easier if EditableRootListBase<T> made a call to a virtaul method OnPropertyChanged(sender, e){
}

As follows:

private void Child_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
    for (int index = 0; index < base.Count; index++)
    {
        if (object.ReferenceEquals(base[index], sender))
        {
            this.OnListChanged(new ListChangedEventArgs(ListChangedType.ItemChanged, index));
            break;
        }
    }

    OnChildPropertyChanged(sender, e);
}

This would make it easy in my collection to deal with the property changed events from the kids


Further I will extend PropertyChangedEventArgs and pass contexul data up to make it easy for my RootList to keep track of calculations, summaries etc.


Thanks,

Rob FireGarden

FireGarden replied on Thursday, July 05, 2007

This kind of thing could be sent in my children INotifyPropertyChanged evet

public class CalculatePropertyChangedEventArgs<T> : PropertyChangedEventArgs
    {
        T _oldValue;
        T _newValue;

        public CalculatePropertyChangedEventArgs(string propertyName, T oldValue, T newValue) : base(propertyName)
        {
            _oldValue = oldValue;
            _newValue = newValue;
        }

        public T OldValue
        {
            get { return _oldValue; }
        }

        public T NewValue
        {
            get { return _newValue; }
        }
    }

wurzulator replied on Friday, July 06, 2007

I take a more manual approach and do this:

                        _milestones = Milestones.GetInstance(dr);
                        Milestones.ListChanged += delegate(object sender, ListChangedEventArgs e)
                        { PropertyHasChanged("Milestones"); };

in the DataPortal_Fetch method and

            _milestones = Milestones.NewInstance();
            Milestones.ListChanged += delegate(object sender, ListChangedEventArgs e)
            { PropertyHasChanged("Milestones"); };

in the DataPortal_Create method

FireGarden replied on Friday, July 06, 2007

I don't think you see what I am trying to do. Rocky subscribes to the INotifyPropertyChanged event on each of the kids but it never actually uses PropertyChangedEventArgs e.

Further to this it doesn't make PropertyChangedEventArgs available to the class. It essentially just throws it away.

RockfordLhotka replied on Sunday, July 08, 2007

Added to the wish list at http://www.lhotka.net/cslanet/wishlist.aspx.