| Performance of setItemCount in SWT Tree [message #479029] |
Sat, 08 August 2009 07:12  |
|
Originally posted by: tom-public.shackell.org.uk
Hi,
I've been trying to create a virtual tree that can view very large
trees, with a large number of root items. However, I'm finding that
setItemCount is taking a very long time to execute, even if the items
aren't currently being viewed. This is on the WIN32 platform.
I've followed the approach described at:
http://www.eclipse.org/articles/Article-SWT-Virtual/Virtual- in-SWT.html
Here is the code I am using:
tree = new Tree(parent, SWT.VIRTUAL | SWT.BORDER);
tree.addListener(SWT.SetData, new Listener() {
@Override
public void handleEvent(Event event) {
TreeItem item = (TreeItem) event.item;
String name = "Item " + event.index;
item.setText(name);
}
});
long begin = System.currentTimeMillis();
tree.setItemCount(70000);
long end = System.currentTimeMillis();
System.out.println("Set item count took "+(end-begin)+" ms");
Typical times I am getting for running setItem count are upwards of 30
seconds, it seems that the even though the tree is virtual setItemCount
is creating all the items in one go.
Interestingly if I use a Table rather than a tree then there are no
performance issues at all. However, although this little snippet is
actually flat, in the actual final program the data will be a tree
(albeit a very long flat tree, with lots of roots).
So I was wondering whether anyone knew whether this is a known problem,
and whether there was any workaround to allow the use of large trees?
Thanks
Tom
------------------------------------------------------------ ------------
Cross posted from eclipse.platform.jface, after looking at it closely
this query isn't actually jface specific so I've reposted on the SWT list.
------------------------------------------------------------ ------------
|
|
|
] 
Search
Help
Register
Login
Home
