Reacting to Java Swing JTabbedPane mouse events over a tab.

MouseReactiveTabbedPane.java

import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JTabbedPane;

import java.util.HashMap;
import java.util.Runnable;

public class MouseReactiveTabbedPane extends JTabbedPane {
      
  private HashMap<Integer,Runnable> runnableMap;
      
  public MouseReactiveTabbedPane() {
    super();
        
    runnableMap = new HashMap<Integer, Runnable>();
    
    final MouseReactiveTabbedPane pane = this;

    this.addMouseMotionListener(
        new MouseMotionAdapter() {
              
          @Override
          public void mouseMoved(MouseEvent e) {
            for (int i = 0; i < pane.getTabCount(); i++){
              if (pane.getBoundsAt(i).contains(e.getPoint())) { 
                    
                if (runnableMap.containsKey(Integer.valueOf(i))) {
                  Runnable tabRunnable = runnableMap.get(Integer.valueOf(i));
                  tabRunnable.run();
                }
                   
              } // if event point is within tab's bounds
            } // for all tab pane indices
          }
    });
  }

  public void setRunnableForTab(int tabIndex, Runnable runnable) {
    runnableMap.put(Integer.valueOf(i), runnable);
  }
}