Swing Widgets

More documents

Recommendations

Info

Which widget fired the event? If all the widgets use the same listener, how canthat actionPerformed() method tellwhich widget generated an event?● public void actionPerformed(ActionEvent e) e.getSource() returns the widget (as an Object) e.getActionCommand() returns a string namefor the event (default: title of button) Can set the action command string directly:● JButton quitButton = new JButton(“Quit”);● quitButton.setActionCommand(“q”);CMPT166: widgets 10 Feb 20104
Using inner classes as listeners Another way: one inner class for each listener Each widget uses its own listener object Each listener is an instance of its own class● public MyWin extends JFrame { public MyWin() { }● JButton q = new JButton(“Quit”);● q.addActionListener( new QListener() ); private class QListener implementsActionListener {● public voidactionPerformed( ActionEvent e );CMPT166: widgets 10 Feb 20105
Page 1 and 2: Swing Widgets10 Feb 2010CMPT166Dr.
Page 3: Event handlingwidget event listener
Page 7 and 8: Other EventListener interfaces Acti
Page 9 and 10: Text fields JTextField:● Single-l
Page 11 and 12: JCheckBox and ItemListener JCheckBo
Page 13: JComboBox Drop-down list for user t

Swing Widgets

Create successful ePaper yourself

Delete template?

Save as template?