Controls and layout managers
Components
Scroll panes
A frame that displays a text area in a scroll pane
Common constructors of the JScrollPane class
| Constructor | Description |
|---|---|
| JScrollPane(Component) | Creates a scroll pane that displays the specified component, along with vertical and horizontal scrollbars as needed. |
| JScrollPane(Component, vertical, horizontal) | Creates a scroll pane that displays the specified component and uses the specified vertical and horizontal policies. |
Fields of the ScrollPaneConstants interface that set scrollbar policies
| Field | Description |
|---|---|
| VERTICAL_SCROLLBAR_ALWAYS | Always display a vertical scrollbar. |
| VERTICAL_SCROLLBAR_AS_NEEDED | Display a vertical scrollbar only when needed. |
| VERTICAL_SCROLLBAR_NEVER | Never display a vertical scrollbar. |
| HORIZONTAL_SCROLLBAR_ALWAYS | Always display a horizontal scrollbar. |
| HORIZONTAL_SCROLLBAR_AS_NEEDED | Display a horizontal scrollbar only when needed. |
| HORIZONTAL_SCROLLBAR_NEVER | Never display a horizontal scrollbar. |
Code that uses a scroll pane with a text area
private JTextArea commentTextArea = new JTextArea(7, 20); commentTextArea.setLineWrap(true); commentTextArea.setWrapStyleWord(true); JScrollPane commentScroll = new JScrollPane(commentTextArea); add(commentScroll);
Code that creates a scroll pane and sets the scroll bar policies
JScrollPane commentScroll =
new JScrollPane(commentTextArea,
ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);