Create a JTree from a list of dot-delimited Strings

Question

I am creating an editor application, and I am having a problem with my menus. In the object menu, I want to display several objects types using a JTree. These object types are dynamically registered by plugins and follow this style:

trigger.button
trigger.lever
out.door.fallgate
trigger.plate
out.door.door
...

This list of names is unsorted and I want to build a TreeNode structure for a JTree like this:

trigger
- button
- lever
- plate
out
- door
  - fallgate
  - door

Additionally, if the user selects a leaf node, I need to recreate the object name (e.g. trigger.button) from the TreePath. Could someone please advise how this can be done.

score 2 · Accepted Answer · answered Oct 31 '12 at 08:51

In psuedocode, this is what you need to do...

public TreeNode buildTree(){
    String[] names = new String[]; // fill this with the names of your plugins

    TreeNode tree;

    // for each plugin name...
    for (int i=0;i<names.length;i++){
        String currentName = names[i];
        String[] splitName = currentName.split(".");

        // loop over the split name and see if the nodes exist in the tree. If not, create them
        TreeNode parent = tree;
        for (int n=0;n<splitName.length;n++){
            if (parent.hasChild(splitName[n])){
                // the parent node exists, so it doesn't need to be created. Store the node as 'parent' to use in the next loop run
                parent = parent.getChild(splitName[n]);
            }
            else {
                // the node doesn't exist, so create it. Then set it as 'parent' for use by the next loop run
                TreeNode child = new TreeNode(splitName[n]);
                parent.addChild(child);
                parent = child;
            }
        }

return tree;
}

This is only psuedocode - you'll need to do the work of implementing the TreeNode methods properly, etc. Give it a try yourself - if you have any more problems, create a question and show us that you've attempted to do it yourself, then we will be more willing to help you solve the minor problems.

No problem. Please remember to 'tick' this answer if you think its the best, so that everyone else knows your problem was solved. — wattostudios, Oct 31 '12 at 10:52
Here is an additional method to get the name of object from the treePath: public static String getElementName(TreePath path) { Object[] nodes = path.getPath(); String result = ""; //read the path, start from index 1 because we don't want the root for (int i=1; i — ShamanMaster, Oct 31 '12 at 11:04

score 1 · Answer 2 · answered Oct 31 '12 at 08:49

1

see Oracle JTree tutorial
part Dynamically Changing a Tree, check the code example
similair idea

answered Oct 31 '12 at 08:49

mKorbel

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Create a JTree from a list of dot-delimited Strings

2 Answers2