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New TreeItem is not updating in UI [message #898279]

Thu, 26 July 2012 02:25

Eclipse User

Hi.
I am using Tree with multiple column and inside that using TreeViewer.

Tree treeSWComponent = new Tree(swComponentComp, SWT.BORDER);

TreeViewer tree_viewer=new TreeViewer(treeSWComponent);

TreeColumn trclmnSwcomponent = new TreeColumn(treeSWComponent, SWT.NONE);
trclmnSwcomponent.setText("Component");

TreeColumn trclmnDataType = new TreeColumn(treeSWComponent, SWT.NONE);
trclmnDataType.setText("Data Type");

TreeColumn trclmnSignalMapping = new TreeColumn(treeSWComponent, SWT.NONE);
trclmnSignalMapping.setText("Signal Mapping");

Here, I am providing the functionality on child TreeItem to create TreeItem but its not showing on UI. But actually its child getting created.

Re: New TreeItem is not updating in UI [message #898299 is a reply to message #898279]

Thu, 26 July 2012 03:10

Eclipse User

Hi,

I really don't understand what are you trying to do. Could you please post more code and better explanation of your problem?

Also when working with the JFace TreeViewer you should rarely create the SWT's TreeColumn and TreeItem on your own.

Re: New TreeItem is not updating in UI [message #898335 is a reply to message #898299]

Thu, 26 July 2012 04:47

Eclipse User

Actually I want one tree with multiple column. I am using TreeViewer since I wanted to use contentProvider and tree to show it in multiple column. (as in attachment)

So on popup menu selection, I am trying to create child item on Tree. It's getting created but when expand it its not showing anything.

Attachment: snippet.JPG
(Size: 28.92KB, Downloaded 273 times)

Re: New TreeItem is not updating in UI [message #898349 is a reply to message #898335]

Thu, 26 July 2012 05:11

Eclipse User

How do you create the child?

Re: New TreeItem is not updating in UI [message #898355 is a reply to message #898349]

Thu, 26 July 2012 05:18

Eclipse User

TreeItem[] selectedItem = tree.getSelection();
TreeItem ti = new TreeItem(selectedItem[0], SWT.None);
ti.setText("Some Text");

Re: New TreeItem is not updating in UI [message #898366 is a reply to message #898355]

Thu, 26 July 2012 05:32

Eclipse User

Well, this is because the TreeViwer uses the model and the content provider for creating the TreeItems.

When you expand an item it asks the content provider for children of the expanded model element.
Since you didn't add the new model element to the model structure, the TreeViewer removed your manually created TreeItem.

Basically, when working with a TreeViewer, you should make structural changes on the input model and then
call TreeViewer.refresh(the child's parent model object) to create new child items.

try to look at this article
http://www.eclipse.org/articles/Article-TreeViewer/TreeViewerArticle.htm

Re: New TreeItem is not updating in UI [message #898372 is a reply to message #898366]

Thu, 26 July 2012 05:42

Eclipse User

Hi,
Thanks for reply.
But how to tell content provider about model change. In
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) method, what are the old and new Input?

Re: New TreeItem is not updating in UI [message #898377 is a reply to message #898372]

Thu, 26 July 2012 05:50

Eclipse User

Read the article. It's really useful.

The inputChanged is useful when your model is somehow observable and you would listen for it's changes.

Do the following things:
- create the model object representing the child you would like to add in the tree
- call treeViewer.refresh(parent model of the new created child model)

the viewer then asks your content provider for children of the parent model, so you have something like this

@Override
public Object[] getChildren(Object parentElement) {
    if (parentElement instanceof ParentModel) {
	return ((ParentModel) parentElement).getChildren();
    }
    other parent model types get their own children ...
}

Re: New TreeItem is not updating in UI [message #898461 is a reply to message #898377]

Thu, 26 July 2012 08:25

Eclipse User

Thanks for your valuable reply.

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