This interface is implemented by components that have a single
JRootPane child: JDialog, JFrame, JWindow, JApplet, JInternalFrame.
The methods in this interface are just covers for the JRootPane
properties, e.g. getContentPane() is generally implemented
like this:
public Container getContentPane() {
return getRootPane().getContentPane();
}
This interface serves as a marker for Swing GUI builders
that need to treat components like JFrame, that contain a
single JRootPane, specially. For example in a GUI builder,
dropping a component on a RootPaneContainer would be interpreted
as frame.getContentPane().add(child) .
For conveniance
JFrame , JDialog , JWindow ,
JApplet and JInternalFrame , by default,
forward, by default, all calls to the add ,
remove and setLayout methods, to the
contentPane . This means you can call:
rootPaneContainer.add(component);
instead of:
rootPaneContainer.getContentPane().add(component);
The behavior of the add and
setLayout methods for
JFrame , JDialog , JWindow ,
JApplet and JInternalFrame is controlled by
the rootPaneCheckingEnabled property. If this property is
true (the default), then calls to these methods are
forwarded to the contentPane ; if false, these
methods operate directly on the RootPaneContainer . This
property is only intended for subclasses, and is therefore protected. |