javax.swing
Class Popup

java.lang.Object
  javax.swing.Popup

Direct Known Subclasses:

PopupFactory.ContainerPopup, PopupFactory.HeavyWeightPopup

public class Popup

extends Object

Popups are used to display a Component to the user, typically on top of all the other Components in a particular containment hierarchy. Popups have a very small life cycle. Once you have obtained a Popup, and hidden it (invoked the hide method), you should no longer invoke any methods on it. This allows the PopupFactory to cache Popups for later use.

The general contract is that if you need to change the size of the Component, or location of the Popup, you should obtain a new Popup.

Popup does not descend from Component, rather implementations of Popup are responsible for creating and maintaining their own Components to render the requested Component to the user.

You typically do not explicitly create an instance of Popup, instead obtain one from a PopupFactory.

Since:

1.4

See Also:

PopupFactory

Nested Class Summary

(package private) static class	Popup.DefaultFrame Used if no valid Window ancestor of the supplied owner is found.
(package private) static class	Popup.HeavyWeightWindow Component used to house window.

Field Summary

private Component

component The Component representing the Popup.

Constructor Summary

protected	Popup() Creates a Popup.
protected	Popup(Component owner, Component contents, int x, int y) Creates a Popup for the Component owner containing the Component contents.

Method Summary

(package private) Component	createComponent(Component owner) Creates the Component to use as the parent of the Popup.
(package private) void	dispose() Frees any resources the Popup may be holding onto.
(package private) Component	getComponent() Returns the Component returned from createComponent that will hold the Popup.
private Window	getParentWindow(Component owner) Returns the Window to use as the parent of the Window created for the Popup.
void	hide() Hides and disposes of the Popup.
(package private) void	pack() Causes the Popup to be sized to fit the preferred size of the Component it contains.
(package private) void	reset(Component owner, Component contents, int ownerX, int ownerY) Resets the Popup to an initial state.
void	show() Makes the Popup visible.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

component

private Component component

The Component representing the Popup.

Constructor Detail

Popup

protected Popup(Component owner,
                Component contents,
                int x,
                int y)

Creates a Popup for the Component owner containing the Component contents. owner is used to determine which Window the new Popup will parent the Component the Popup creates to. A null owner implies there is no valid parent. x and y specify the preferred initial location to place the Popup at. Based on screen size, or other paramaters, the Popup may not display at x and y.

Parameters:

owner - Component mouse coordinates are relative to, may be null

contents - Contents of the Popup

x - Initial x screen coordinate

y - Initial y screen coordinate

Throws:

IllegalArgumentException - if contents is null

Popup

protected Popup()

Creates a Popup. This is provided for subclasses.

Method Detail

show

public void show()

Makes the Popup visible. If the Popup is currently visible, this has no effect.

hide

public void hide()

Hides and disposes of the Popup. Once a Popup has been disposed you should no longer invoke methods on it. A disposed Popup may be reclaimed and later used based on the PopupFactory. As such, if you invoke methods on a disposed Popup, indeterminate behavior will result.

dispose

void dispose()

Frees any resources the Popup may be holding onto.

reset

void reset(Component owner,
           Component contents,
           int ownerX,
           int ownerY)

Resets the Popup to an initial state.

pack

void pack()

Causes the Popup to be sized to fit the preferred size of the Component it contains.

getParentWindow

private Window getParentWindow(Component owner)

Returns the Window to use as the parent of the Window created for the Popup. This creates a new Frame each time it is invoked. Subclasses that wish to support a different Window parent should override this.

createComponent

Component createComponent(Component owner)

Creates the Component to use as the parent of the Popup. The default implementation creates a Window, subclasses should override.

getComponent

Component getComponent()

Returns the Component returned from createComponent that will hold the Popup.