Setting the Initial Focused Component in a Window : Focus Event « Event « Java





Setting the Initial Focused Component in a Window

  
import java.awt.Component;
import java.awt.FlowLayout;
import java.awt.Window;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Main {
  public static void main(String[] argv) throws Exception {
    JFrame frame = new JFrame();
    JButton component1 = new JButton("1");
    JButton component2 = new JButton("2");
    JButton component3 = new JButton("3");

    frame.setLayout(new FlowLayout());
    frame.add(component1);
    frame.add(component2);
    frame.add(component3);

    InitialFocusSetter.setInitialFocus(frame, component2);

    frame.pack();
    frame.setVisible(true);
  }
}

class InitialFocusSetter {
  public static void setInitialFocus(Window w, Component c) {
    w.addWindowListener(new FocusSetter(c));
  }
}

class FocusSetter extends WindowAdapter {
  Component initComp;

  FocusSetter(Component c) {
    initComp = c;
  }

  public void windowOpened(WindowEvent e) {
    initComp.requestFocus();
    e.getWindow().removeWindowListener(this);
  }
}

   
    
  










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