GUI

[Smitha Prasad]

i want to make a button a listener to the action from a source which is another button. for example if i have two buttons, yellow button and blue button and i want to make the blue button a listener to the yellow button... if the yellow button is clicked the label of the blue button should change.

[Ali Ashraf]

Dear smitha
try this code:code:

import java.awt.*;
import java.awt.event.*;
class ButtonTest implements ActionListener {
   Button blueButton;
   Button yellowButton;
   public ButtonTest () {
      blueButton = new Button ("Blue");
      yellowButton = new Button ("Yellow");
      yellowButton.addActionListener (this);
      Frame f = new Frame ("Frame Test");
      f.setLayout (new FlowLayout ());
      f.add (yellowButton);
      f.add (blueButton);
      f.setSize (400, 300);
      f.setVisible (true);
   }
//===========================
   public static void main (String arg[]) {
      new ButtonTest ();
   }
//=============================
   public void actionPerformed (ActionEvent ae) {
      if (ae.getSource () == yellowButton)
         blueButton.setLabel ("Not blue now");
   }
}

[ April 10, 2002: Message edited by: Cindy Glass ]

[Smitha Prasad]

thanks Ashraf, the reference to the listener is through "this". is there any other mechanism of giving reference to the blue button , i.e making the button a listener directly.

[Dirk Schreckmann]

Well, I'm not sure I'm understanding your question exactly. Would you elaborate a bit?

[Sayed Ibrahim Hashimi]

I'm not sure I know exactly what you are talking about either.
Why would you want your button handle the events? Its a button not an event handler.
If you are using Swing you might want to look into the Action class.
[ April 10, 2002: Message edited by: Ibrahim Hashimi ]
[ April 10, 2002: Message edited by: Ibrahim Hashimi ]

[Ali Ashraf]

No the button cannot act as an event handler.
button is a component, it generates an event and a listener handel this event.
please look at Events and Listeners.
[ April 10, 2002: Message edited by: Muhammad Ali Ashraf ]