How to Use the ButtonGroup Component
ButtonGroup component manages the selected/unselected state for a set of buttons. For the group, the
ButtonGroup instance guarantees that only one button can be selected at a time.
Initially, all buttons managed by a
ButtonGroup instance are unselected.
How to Use ButtonGroup Features
You can use
ButtonGroup with any set of objects that inherit from
AbstractButton. Typically a button group contains instances of
JRadioButton, JRadioButtonMenuItem, or
JToggleButton. It would not make sense to put an instance of
JMenuItem in a button group because
JMenuItem do not implement the select/deselect button state.
In general, you will typically follow these steps to write code that uses a
ContextPanetogether with a layout manager
- Declare and configure a set of radio buttons or toggle buttons
- Instantiate a
- Call the
addmethod on that buttongroup object in order to add each button to the group.
For details and a code example, see How to Use Radio Buttons. It shows how to use a
ButtonGroup component to group a set of RadioButtons set into a JPanel.
The ButtonGroup API
|Constructor or Method||Purpose|
| void add(AbstractButton)
|Add a button to the group, or remove a button from the group.|
| public ButtonGroup getGroup()
|public ButtonGroup clearSelection()||Clears the state of selected buttons in the ButtonGroup. None of the buttons in the ButtonGroup are selected .|
The following demonstration application uses the ButtonGroup component to group radio buttons displaying on a Window.
||How to Use Radio Buttons||Uses radio buttons to determine which of five images it should display.|