How to change style (color, font) of a single JTree node

Question

I have two JTree in two panels in a JFrame. I want to change the style(color and font) of nodes on drag and drop from one tree to the other.Please provide me a way to change the color of a JTree node permanently.

Answer 1

To start, you will need to have a data object that can handle style and color. You could subclass DefaultMutableTreeNode and add these data items with getts and setters

Then you'd need to create a custom TreeCellRenderer. I recommend extending DefaultTreeCellRenderer, and in the overridden handler, checking for your custom class, and modifying the JLabel output to use the Font and Color if these values are set

Answer 2

Create your own CellRenderer. To give the appropriate behaviour to your MyTreeCellRenderer, you will have to extend DefaultTreecellRenderer and override the getTreeCellRendererComponent method.

public class MyTreeCellRenderer extends DefaultTreeCellRenderer {

    @Override
    public Component getTreeCellRendererComponent(JTree tree, Object value,
            boolean sel, boolean exp, boolean leaf, int row, boolean hasFocus) {
        super.getTreeCellRendererComponent(tree, value, sel, exp, leaf, row, hasFocus);

        // Assuming you have a tree of Strings
        String node = (String) ((DefaultMutableTreeNode) value).getUserObject();

        // If the node is a leaf and ends with "xxx"
        if (leaf && node.endsWith("xxx")) {
            // Paint the node in blue
            setForeground(new Color(13, 57 ,115));
        }

        return this;
    }
}

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Finally, say your tree is called myTree, set your CellRenderer to it:

myTree.setCellRenderer(new MyTreeCellRenderer());