Popup & PopupFactoryCertain Components, such as JPopupMenu
and JToolTip, present themselves above all other
Components in a particular containment hierarchy.
Rather than each of these Components containing the
same code to obtain the same behavior, they delegate to a
Popup which can be obtained from a
PopupFactory. A Popup is able to display
a Component at a particular location on the screen.
Based on the size and location of the requested
Component, PopupFactory returns an
appropriate Popup.
Previously, Popup and PopupFactory
were package private. For JDK 1.4, we have exposed these classes to
enable custom look and feel implementations to create their own
Popups. This allows other look and feels to position
menus in an appropriate manner for their look and feel. To this
end, we have made these classes public:
public class PopupFactory {
public static void setSharedInstance(PopupFactory factory);
public static PopupFactory getSharedInstance();
public Popup getPopup(Component owner, Component contents, int x, int y) throws IllegalArgumentException;
}
public class Popup {
protected Popup(Component owner, Component contents, int x, int y);
protected Popup();
public void show();
public void hide();
}
To enable the Popup used by JPopupMenu
to be replaced by the UI, we added the following to PopupMenuUI:
public Popup getPopup(JPopupMenu popup, int x, int y);
PopupMenuUI.getPopup's implementation obtains the
Popup from the shared PopupFactory, but
custom look and feel implementations may override this and return
whatever Popup they desire.
JPopupMenu previously defined the method
setLocation. Prior to this release, this method would
invoke setLocation on the Popup, but as
we have removed this method from Popup,
JPopupMenu now recreates the Popup.
JPopupMenu also defined the method
setPopupSize, which invoked setSize on
the Popup if it was visible. Internally, we changed
this method to set the preferred size of the
JPopupMenu, which gives the same results. If the
JPopupMenu is visible when this is invoked, the
Popup will be recreated. The JPopupMenu
javadoc changed to reflect the new behavior:
public void setPopupSize(Dimension d);
public void setPopupSize(int width, int height);
