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From Greg Brown <gkbr...@mac.com>
Subject Re: Getting a TreeView node from mouse click
Date Fri, 03 Sep 2010 11:57:47 GMT
> 1.       Is there a generic method that takes the “Sequence.Tree.Path” value and traverses
the TreeView data model to come up with the correct tree node that corresponds to that path?
 Or do I have to write my own, depending on the type of tree node used?  It’s obviously
not hard, but I was trying to save having to write it myself.

You are correct - Sequece.Tree.get() etc. can be used to access and manipulate nested structures.

> 2.       I don’t see any place for “userData” in the TreeNode object, so if I want
to add stuff (for instance, that is language-independent so I can do string compares on it
in any language), do I have to subclass TreeNode and/or TreeBranch to create a compatible
object to populate the TreeView data model with?

The reason there is no "userData" property on TreeNode is because TreeNode and TreeBranch
are simply the default implementations for these classes. Any class that implements List can
be a branch, and any Object can be a leaf - you just need to define an appropriate renderer.
The default TreeViewNodeRenderer is capable of rendering TreeNode and TreeBranch, but it is
fairly easy to write your own - you can see an example of a custom renderer in the XML Viewer
demo:

  http://svn.apache.org/repos/asf/pivot/trunk/demos/src/org/apache/pivot/demos/xml/

This application uses a custom renderer to present instance of org.apache.pivot.xml.Element
and org.apache.pivot.xml.TextNode as branches and leaves, respectively. 

Depending on how you get the data for your tree view, you may find that a custom renderer
is more efficient. For example, if you return a tree structure as XML from the server, you
could do something similar to what is done in XML Viewer. You can simply use the deserialized
XML (obtained from XMLSerializer) as your tree model data. This saves the step of converting
your data into TreeNodes and TreeBranches for presentation in the TreeView.

> 3.       If I create my own classes, can I use them in a .wtkx (now .bxml) file (with
the appropriate namespace definitions)? 

Yes.

> Is there any special setup required for the XML parsing to make my own namespaces accessible
there?

Nope, not really. You may find the WTKX Primer helpful in understanding how WTKX maps to Java:

  http://pivot.apache.org/tutorials/wtkx-primer.html

G


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