Roman Rdgz Roman Rdgz - 2 months ago 33
Java Question

JTree: Selecting all nodes programatically

I have a Jtree, and 2 buttons to select and unselect all nodes. I made an attempt like this:

selectAll = new JButton("Select all");
selectAll.addActionListener(new ActionListener (){
@Override
public void actionPerformed(ActionEvent e) {
int row = 0;
while (row < curvesTree.getRowCount())
{
curvesTree.expandRow(row);
row++;
}
int entradasTree = curvesTree.getRowCount();
for(int i=0; i<entradasTree; i++){
TreePath path = curvesTree.getPathForRow(i);
curvesTree.setSelectionPath(path);
}
}
});

unselectAll = new JButton("Unselect all");
unselectAll.addActionListener(new ActionListener (){
@Override
public void actionPerformed(ActionEvent e) {
curvesTree.clearSelection();
}
});


The unselect button seems to be working, but the select all only expands the JTree and selects the last node. I think every time a node is selected programatically, I'm unselecting the former one.

JTree is configured like this:

curvesTree = new JTree(rootNode);
curvesTree.setExpandsSelectedPaths(true);
curvesTree.getSelectionModel().setSelectionMode(TreeSelectionModel.
DISCONTIGUOUS_TREE_SELECTION);

Answer

the unselect happens because you are setting a new selection path instead of adding. In the loop after expanding, instead do

 curvesTree.addSelectionPath(...)

EDIT

reading api is always instructive, even after years ;-) Just found a much simper method, which leaves all the work to the tree:

tree.setSelectionInterval(0, tree.getRowCount());
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