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JFace Viewer [message #336259]

Wed, 03 June 2009 22:48

Eclipse User

Is there any way I can stop my TreeViewer from completely collapsing on
a setInput()?

Re: JFace Viewer [message #336260 is a reply to message #336259]

Thu, 04 June 2009 01:26

Eclipse User

Andy Czerwonka wrote:
> Is there any way I can stop my TreeViewer from completely collapsing on
> a setInput()?

I think that its not a good idea for TreeViewer to expand all when
setting the input. It would have severe performance impact if the tree
depth is more or if fetching of each element is time consuming.

However, if you really need to do that for your app, you can call
treeViewer.expandAll() or treeViewer.expandToLevel() methods

- Prakash
---
http://blog.eclipse-tips.com

Re: JFace Viewer [message #336277 is a reply to message #336260]

Thu, 04 June 2009 18:54

Eclipse User

Originally posted by: wim.jongman.gmail.com

Hi Andy,

Alternatively you can get the current expanded nodes before setinput and
expand exactly that after setinput. Stop the tree from drawing in between and
show a nice progress dialog if it takes longer.

Best Regards,

Wim Jongman

> Andy Czerwonka wrote:
>> Is there any way I can stop my TreeViewer from completely collapsing on
>> a setInput()?
>
> I think that its not a good idea for TreeViewer to expand all when
> setting the input. It would have severe performance impact if the tree
> depth is more or if fetching of each element is time consuming.
>
> However, if you really need to do that for your app, you can call
> treeViewer.expandAll() or treeViewer.expandToLevel() methods
>
> - Prakash
> ---
> http://blog.eclipse-tips.com

Re: JFace Viewer [message #336454 is a reply to message #336259]

Sat, 13 June 2009 00:19

Eclipse User

Andy Czerwonka wrote:
> Is there any way I can stop my TreeViewer from completely collapsing on
> a setInput()?

In order to stop this from happening your domain objects that are being
displayed in the TreeView have to correctly implement compareTo, equals
and HasCode. Once you have done this it should stop happening.

An additional thing I do is that after I add an item to the list backing
the tree viewer I create a TreeSelection object and call the
setSelection method on the TreeViewer passing it the selection object,
If the TreeSelection object is created correctly the item you just added
should be the selected item in the tree with the branch it is in expanded.

Hope this helps, good luck.

Re: JFace Viewer [message #336455 is a reply to message #336454]

Sat, 13 June 2009 03:35

Eclipse User

As an alternative you can also set an IElementComparer on the viewer.

Tom

exquisitus schrieb:
> Andy Czerwonka wrote:
>> Is there any way I can stop my TreeViewer from completely collapsing
>> on a setInput()?
>
> In order to stop this from happening your domain objects that are being
> displayed in the TreeView have to correctly implement compareTo, equals
> and HasCode. Once you have done this it should stop happening.
>
> An additional thing I do is that after I add an item to the list backing
> the tree viewer I create a TreeSelection object and call the
> setSelection method on the TreeViewer passing it the selection object,
> If the TreeSelection object is created correctly the item you just added
> should be the selected item in the tree with the branch it is in expanded.
>
> Hope this helps, good luck.

Re: JFace Viewer [message #336471 is a reply to message #336455]

Mon, 15 June 2009 21:50

Eclipse User

Interesting information on the domain objects needing to be Comparable.
That accents a behavior change I noted in my TreeViewer when I changed my
top level object to implement Comparable and overrode compareTo().
For not collapsing the TreeViewer on setInput(), however, would it be Ok
if it reset to a default expand level? I believe setAutoExpandLevel()
will do that for you...

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