Mega Code Archive
Creating a Custom Renderer
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import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import java.util.Vector;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellRenderer;
class TreeNodeVector<E> extends Vector<E> {
String name;
TreeNodeVector(String name) {
this.name = name;
}
TreeNodeVector(String name, E elements[]) {
this.name = name;
for (int i = 0, n = elements.length; i < n; i++) {
add(elements[i]);
}
}
public String toString() {
return "[" + name + "]";
}
}
class Employee {
public String firstName;
public String lastName;
public float salary;
public Employee(String f, String l, float s) {
this.firstName = f;
this.lastName = l;
this.salary = s;
}
}
class EmployeeCellRenderer implements TreeCellRenderer {
JLabel firstNameLabel = new JLabel(" ");
JLabel lastNameLabel = new JLabel(" ");
JLabel salaryLabel = new JLabel(" ");
JPanel renderer = new JPanel();
DefaultTreeCellRenderer defaultRenderer = new DefaultTreeCellRenderer();
Color backgroundSelectionColor;
Color backgroundNonSelectionColor;
public EmployeeCellRenderer() {
firstNameLabel.setForeground(Color.BLUE);
renderer.add(firstNameLabel);
lastNameLabel.setForeground(Color.BLUE);
renderer.add(lastNameLabel);
salaryLabel.setHorizontalAlignment(JLabel.RIGHT);
salaryLabel.setForeground(Color.RED);
renderer.add(salaryLabel);
renderer.setBorder(BorderFactory.createLineBorder(Color.BLACK));
backgroundSelectionColor = defaultRenderer.getBackgroundSelectionColor();
backgroundNonSelectionColor = defaultRenderer.getBackgroundNonSelectionColor();
}
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected,
boolean expanded, boolean leaf, int row, boolean hasFocus) {
Component returnValue = null;
if ((value != null) && (value instanceof DefaultMutableTreeNode)) {
Object userObject = ((DefaultMutableTreeNode) value).getUserObject();
if (userObject instanceof Employee) {
Employee e = (Employee) userObject;
firstNameLabel.setText(e.firstName);
lastNameLabel.setText(e.lastName);
salaryLabel.setText("" + e.salary);
if (selected) {
renderer.setBackground(backgroundSelectionColor);
} else {
renderer.setBackground(backgroundNonSelectionColor);
}
renderer.setEnabled(tree.isEnabled());
returnValue = renderer;
}
}
if (returnValue == null) {
returnValue = defaultRenderer.getTreeCellRendererComponent(tree, value, selected, expanded,
leaf, row, hasFocus);
}
return returnValue;
}
}
public class EmployeeTree {
public static void main(String args[]) {
JFrame frame = new JFrame("Book Tree");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Employee javaBooks[] = { new Employee("A", "F", 9.99f), new Employee("B", "E", 4.99f),
new Employee("C", "D", 9.95f) };
Employee netBooks[] = { new Employee("AA", "CC", 9.99f), new Employee("BB", "DD", 9.99f) };
Vector<Employee> javaVector = new TreeNodeVector<Employee>("A", javaBooks);
Vector<Employee> netVector = new TreeNodeVector<Employee>("As", netBooks);
Object rootNodes[] = { javaVector, netVector };
Vector<Object> rootVector = new TreeNodeVector<Object>("Root", rootNodes);
JTree tree = new JTree(rootVector);
TreeCellRenderer renderer = new EmployeeCellRenderer();
tree.setCellRenderer(renderer);
JScrollPane scrollPane = new JScrollPane(tree);
frame.add(scrollPane, BorderLayout.CENTER);
frame.setSize(300, 300);
frame.setVisible(true);
}
}
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