Trees - The Definitive Guide to Java Swing - page 632

} else {
tipKey = tree.convertValueToText(value, selected, expanded, leaf,
row, hasFocus);
}
renderer.setToolTipText((String)tipTable.get(tipKey));
}
return renderer;
}
}

Note The example in Listing 17-6 takes advantage of the JTree method public String
convertValueToText(Object value, boolean selected, boolean expanded, boolean leaf,
int row boolean hasFocus) to convert the tree node value to a text string. The value parameter is
normally a DefaultMutableTreeNode , described later in this chapter. When the value parameter is not a
DefaultMutableTreeNode , using convertValueToText() allows the renderer to support other types of
tree nodes.

■

Using the new ToolTipTreeCellRenderer class simply involves creating the Properties list,
filling it with tooltip text for the necessary nodes, and then associating the renderer with the
tree. Figure 17-11 shows the renderer in action.

Figure 17-11. A JTree with tooltips, using the new ToolTipTreeCellRenderer

The complete sample program used to generate the screen in Figure 17-11 is shown next
in Listing 17-7. This tree uses the list of system properties as the tree nodes. The tooltip text is
the current setting for the specific property. When using the ToolTipTreeCellRenderer , be sure
to register the tree with the ToolTipManager .

Listing 17-7. Using a Tooltip Cell Renderer

import javax.swing.*;
import javax.swing.tree.*;
import java.awt.*;
import java.util.*;