Question

I’m creating this application, it has various components (oscillators, effects) to draw a visual waveform. You use controls on the GUI to change the component parameters.

When you interact with one of the controls, I need to update the associated component, and then redraw the output.

public JPanel createOscPanel(Osc o)
 {
 JPanel cbPanel = new JPanel(); 
 final String[] comboItems = {"Sine", "Custom", "FSaw", "FSquare"};
 JComboBox cb = new JComboBox(comboItems);
 cbPanel.add(cb); 

 cb.addActionListener(this);

 return cbPanel; 
 }

public void actionPerformed(ActionEvent e) {
    JComboBox cb = (JComboBox)e.getSource();
    int value = cb.getSelectedIndex();

    System.out.println(value); 
} 

In this example – how can I pass in that oscillator so I can run a setWaveType() method on it?

Answer 1

Create anonymous handler and change parameter of createOscPanel.

public JPanel createOscPanel(final Osc o)
 {
   JPanel cbPanel = new JPanel(); 
   final String[] comboItems = {"Sine", "Custom", "FSaw", "FSquare"};
   JComboBox cb = new JComboBox(comboItems);
   cbPanel.add(cb); 

   cb.addActionListener(new ActionListener(){
       public void actionPerformed(ActionEvent e) {
           JComboBox cb = (JComboBox)e.getSource();
           int value = cb.getSelectedIndex();
           o.setWaveType();
           System.out.println(value); 
      } 
    });
  return cbPanel; 
 }