labelled push-button e.g. An OK button. In AWT (Advanced Windowing Toolkit) you use the Button class and in Swing
Putting \n in the Button’s label text won’t
give you a multiline label. You must use a javax.swing. JButton. You feed it HTML (Hypertext Markup Language) containing a <br>. Similarly if you
want to decorate your buttons with images, or you want non-rectangular buttons, you must use JButton.
Even when you use a round button image, it still lives on a rectangular transparent background. This means if
the user clicks in the transparent corners, it still counts as clicking the button. It also counts for the
rollover button highlighting.
If you did a setLayout ( null ); you could absolutely
position your buttons so they overlapped slightly in the transparent corners. This would let you pack the buttons
more closely than the surrounding rectangles would naturally allow.
Creating and Configuring a JButton
The JButton.setActionCommand does not set up an ActionListener. It simply records a string you may retrieve later with getActionCommand. It just helps you remember what to do in the ActionListener when that button is pressed. It helps you sort of which button was pressed, and
just what you are supposed to do about it. Alternatively, you can hide information with setName, though I normally use that for debugging field names, automatic label generation, or
prompting information. To hide binary data, put a 16-bit unsignd number in the first char of the String.
Windows users are used to hitting Enter instead of clicking a button, if the button has focus. This does not
always work. If you are using the Metal look and feel, you need to press space instead.
Swing paints a thin box on a button if it has focus. You can suppress that with:
theButton.setFocusPainted( false );
Simulating a Button Click
Here are four methods so simulate the user clicking a JButton.
- Invoke the same appication method your JButton’s ActionListener does. This is the simplest if you know at compile time what the method
- Use JButton.doClick().
- Use Robot.keyPress.
- Create a synthetic event and enqueue it.
will not work if you combine it with JButton. setBorder.
That is because setMargin is implemented as a Border.
Use a compound Border to get extra space around the text and a decorative border.
See the example code for how.
- If the JButtons are too small, fluff them up with setMargin or with the ipadx and ipady
Oracle’s Javadoc on JButton
class : available:
Oracle’s Javadoc on Robot.keyPress