ej.microui.display

Class Displayable

java.lang.Object

ej.microui.display.Displayable

public abstract class Displayable
extends java.lang.Object

Displayable is an abstract class which defines the very objects that can be shown on a Display.
A Displayable object is built for a specific Display which can not be changed afterwards. A Displayable may be shown or hidden, but at most one Displayable is shown per Display.

Subclasses should define the Displayable contents and their possible interactions with the user.

By default, a new Displayable object is not visible on its display.

See Also:

Display

Constructor Summary

Constructors

Constructor and Description
Displayable(Display display) The newly created displayable is built for the given display and is hidden.

Method Summary

Modifier and Type	Method and Description
abstract EventHandler	getController() Gets the displayable controller or null if none.
Display	getDisplay() Gets the displayable's display.
void	hide() Sets the displayable as hidden on its display.
protected void	hideNotify() This method is called by system as soon as the displayable becomes hidden.
boolean	isShown() Checks whether the displayable is visible on its display.
abstract void	paint(GraphicsContext g) Draws the displayable.
void	repaint() Requests a repaint for the entire displayable.
void	show() Sets the displayable as visible on its display.
protected void	showNotify() This method is called by system as soon as the displayable becomes visible.

Methods inherited from class java.lang.Object

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

Constructor Detail

Displayable

public Displayable(Display display)

The newly created displayable is built for the given display and is hidden.

Parameters:

display - the display for which the displayable is created

Throws:

java.lang.NullPointerException - if the given display is null

Method Detail

getDisplay

public Display getDisplay()

Gets the displayable's display.

The returned display can't be null.

Returns:

the displayable's display.

isShown

public boolean isShown()

Checks whether the displayable is visible on its display.

Returns:

true if the displayable is currently visible, false otherwise

show

public void show()
          throws java.lang.SecurityException

Sets the displayable as visible on its display.

Throws:

java.lang.SecurityException - if a security manager exists and does not allow the caller to get the display.

hide

public void hide()

Sets the displayable as hidden on its display. If the displayable is not visible, this method has no effect.

showNotify

protected void showNotify()

This method is called by system as soon as the displayable becomes visible. Application should override this method to control its own displayables.

hideNotify

protected void hideNotify()

This method is called by system as soon as the displayable becomes hidden. Application should override this method to control its own displayables.

repaint

public void repaint()

Requests a repaint for the entire displayable. Calling this method may result in subsequent call(s) to paint(GraphicsContext) on the displayable.

If the displayable is not visible, this call has no effect.

The call(s) to paint(GraphicsContext) occurs asynchronously to this call. That is, this method will not block waiting for paint(GraphicsContext) to finish.

To synchronize with the paint(GraphicsContext) routine, applications can use either Display.callSerially(Runnable) or Display.waitForEvent(), or they can code explicit synchronization into their paint(GraphicsContext) routine.

paint

public abstract void paint(GraphicsContext g)

Draws the displayable. This method must be implemented by subclasses to render graphics on a display.

Parameters:

g - the GraphicsContext of the displayable's Display.

getController

public abstract EventHandler getController()

Gets the displayable controller or null if none.

Returns:

the displayable controller or null.

Since:

2.0