[Kde-java] KListView and KListViewItem

[Paul Sprakes]

On Saturday 13 Mar 2004 09:06, Richard Dale wrote:
> On Friday 12 March 2004 20:21, Paul Sprakes wrote:
> > I have subclassed KListViewItem with a class that takes a delegate object
> > which I can inspect when I catch the various signals from KListView. I
> > have found though that while items added as children to KListView will
> > come through the signal mechanism as the correct subclass, items added as
> > children of a ListViewItem always come back as QListViewItem. I cannot
> > cast the QListViewItem items back into my subclass and there is no way
> > for me to get any info about what has been selected other then the
> > displayed text.
> >
> > Can anyone shed any light on this or tell me what I am doing wrong?
> >
> > //this is connected to the "executed(QListViewItem)" signal
> > public void treeItemSelected(QListViewItem item) {
> > 	System.out.println(item);
> > }
> >
> > private void populateServerTree() {
> >   Iterator servers = app.getServers().iterator();
> >   while(servers.hasNext()) {
> >     NewsServer server = (NewsServer)servers.next();
> >     ListViewItem serverNode = new ListViewItem(tree,
> > server,server.getHost()); Iterator groups =
> > server.getSubscribedGroups().iterator();
> >     while(groups.hasNext()) {
> >       NewsGroup group = (NewsGroup)groups.next();
> >       ListViewItem groupNode = new ListViewItem(serverNode, group,
> > group.getName());
> >     }
> >   }
> > }
>
> I think what might have happened here is that the ListViewItems that appear
> as QListViewItems have been garbage collected. However, the C++ underlying
> instance wouldn't have been deleted as it was still in the QListView tree
> with an 'owner' C++ instance. Then, when the signal was emitted the qtjava
> runtime looks for a java instance corresponding to the C++ one, but it
> doesn't find one, and instantiates a new QListViewItem instance.
>
> A work round might be to create an ArrayList and add each ListViewItem to
> that, and then there would always be a live references and java wouldn't
> garbage collect them. I would be interested if that fixes it.

You are correct, it works. Looks like something i'll have to keep my eye on in 
future.

Thanks for your help.

> -- Richard
> _______________________________________________
> Kde-java mailing list
> Kde-java at kde.org
> https://mail.kde.org/mailman/listinfo/kde-java