Java Reference
In-Depth Information
JFrame f = new JFrame();
getContentPane().add(new JButton("Ok")); // Add the button
to the frame's content pane.
f.pack();
f.setVisible(true);
RootPaneContainer
complements
getContentPane()
with a
void
setContentPane(Container content)
methodthatyou'llfindhelpfulwhen
you want to replace the current content pane with a new content pane. The following
exampledemonstrates
setContentPane()
bycreatinganewpanel,populatingthe
panel(asdescribedbythecomment),andusing
setContentPane()
toreplacethe
existing content pane with this panel:
JFrame f = new JFrame();
JPanel pnl = new JPanel();
// Populate the panel.
f.setContentPane(pnl);
Tip
Becausetheglasspaneispaintedlast,youcandrawovertheGUI.Also,because
eventsarefirstsenttotheglasspane,youcanusethispanetoblockmouseandother
events from reaching the GUI.
JFrame
declares a
void setDefaultCloseOperation(int opera-
tion)
method for specifying the operation that occurs by default when the user
choosestoclosethiswindow.Theargumentpassedto
operation
isoneofthefollow-
ingconstants(declaredinthe
javax.swing.WindowConstants
interface,which
JFrame
and
JDialog
implement):
•
DO_NOTHING_ON_CLOSE
:Don'tdoanything;requiretheprogramtohandle
the operation in the
windowClosing()
method of a registered
Win-
dowListener
object. This operation is equivalent to what you would do in
AWT as discussed earlier.
•
HIDE_ON_CLOSE
: Automatically hide the frame window after invoking any
registered
WindowListener
objects. This is the default operation.
•
DISPOSE_ON_CLOSE
:Automaticallyhideanddisposeoftheframewindow
after invoking any registered
WindowListener
objects.
•
EXIT_ON_CLOSE
(alsodeclaredin
JFrame
):Exittheapplicationvia
Sys-
tem.exit()
.