I have a JTree
and an awt.Canvas
. When i select multiple objects from within the Canvas
into the objList
, I want all the selected items to be shown inside the JTree
as selected. That means for example if I have 2 objects selected, both their paths to root should be expanded, and also each selected object should have its corresponding TreeNode
selected. My JTree has TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION
.
Here is a sample of the expand funcion i use :
public void selectTreeNodes() {
HashMap <String, MyEntity> entities = ...;
Iterator it = entities.keySet().iterator();
while (it.hasNext()) {
String str = it.next().toString();
MyEntity ent = entities.get(str);
if (ent.isSelected()) {
DefaultMutableTreeNode searchNode = searchNode(ent.getName());
if (searchNode != null) {
TreeNode[] nodes = ((DefaultTreeModel) tree.getModel()).getPathToRoot(searchNode);
TreePath tpath = new TreePath(nodes);
tree.scrollPathToVisible(tpath);
tree.setSelectionPath(tpath);
}
}
}
}
public DefaultMutableTreeNode searchNode(String nodeStr)
{
DefaultMutableTreeNode node = null;
Enumeration enumeration= root.breadthFirstEnumeration();
while(enumeration.hasMoreElements()) {
node = (DefaultMutableTreeNode)enumeration.nextElement();
if(nodeStr.equals(node.getUserObject().toString())) {
return node;
}
}
//tree node with string node found return null
return null;
}
In my current state, if I select a single object, it will be selected in the JTree
and its TreePath
will be shown.
But if entities
has more than 1 object selected, it will display nothing, my JTree
will remain unchanged.
You are looking for the TreeSelectionModel
of the JTree
(use the getter). Use the TreeSelectionModel#setSelectionPaths
for multiple paths. Now you are only setting one node selected due to your tree.setSelectionPath(tpath);
call. The TreeSelectionModel
also has methods to add/remove to an existing selection ,... (basically everything you might need in the future).
An interesting method for the expansion is the JTree#setExpandsSelectedPaths
method which allows to configure the JTree
to automatically expand selected paths. If you want to manage this manually, you can use the JTree#setExpandedState
method