ej.mwt

Class Desktop

java.lang.Object

ej.microui.display.Displayable

ej.mwt.Desktop

All Implemented Interfaces:

Renderable

public class Desktop
extends ej.microui.display.Displayable
implements Renderable

A desktop is the top-level object that can be displayed on a Display.
A desktop is built for a specific Display, and that relationship cannot be modified.
A desktop may be shown or hidden, but at most one desktop is shown per Display.

A desktop can contains several Panel instances.
These panels are stored in a list. The order of the list defines the front-to-back stacking order of the panels within the desktop. The first panel in the list is at the back of the stacking order.

See Also:

Display, Panel

Constructor Summary

Constructors

Constructor and Description
Desktop() Creates a new desktop on the default display. Identical to new Desktop(Display.getDefaultDisplay()).
Desktop(ej.microui.display.Display display) Creates a new desktop on the specified display.

Method Summary

Modifier and Type	Method and Description
Panel	getActivePanel() Gets this desktop's active panel.
ej.microui.util.EventHandler	getController()
ej.microui.util.EventHandler	getEventHandler() Gets the event handler.
int	getHeight() Returns the height of this desktop: it is equal to the height of its associated display.
Panel[]	getPanels() Gets the list of the panels being shown on this desktop. A panel is added to this list when it executes Panel.show(Desktop) and removed when it executes Panel.hide().
int	getWidth() Returns the width of this desktop: it is equal to the width of its associated display.
int	getX() Returns the x coordinate of this desktop, which is always 0.
int	getY() Returns the y coordinate of this desktop, which is always 0.
boolean	handleEvent(int event) Called by the system if no widget nor panel in the focused hierarchy has consumed the event.
void	hideNotify() The desktop is hidden from its display.
boolean	isAccessible(Panel panel) Checks whether or not a panel is accessible to the user.
void	paint(ej.microui.display.GraphicsContext g)
Panel	panelAt(int x, int y) Gets the panel at the specified position.
void	render(ej.microui.display.GraphicsContext g) Renders the renderable on the given graphics context.
void	repaint(int x, int y, int width, int height) Requests a repaint of a zone of this desktop.
void	revalidate() Lays out all the hierarchy of this desktop.
void	setActivePanel(Panel panel) Sets the specified panel as the active one on this desktop.
void	setEventHandler(ej.microui.util.EventHandler eventHandler) Sets the event handler.
void	showNotify() The desktop is visible on its display.
void	validate() Lays out all the hierarchy of this desktop.

Methods inherited from class ej.microui.display.Displayable

getDisplay, hide, isShown, repaint, show

Methods inherited from class java.lang.Object

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

Methods inherited from interface ej.mwt.Renderable

isShown, repaint

Constructor Detail

Desktop

public Desktop()

Creates a new desktop on the default display.
Identical to new Desktop(Display.getDefaultDisplay()).

Desktop

public Desktop(ej.microui.display.Display display)
        throws java.lang.NullPointerException

Creates a new desktop on the specified display. The newly created desktop is hidden.

Parameters:

display - the display for which the desktop is created.

Throws:

java.lang.NullPointerException - if display is null.

Method Detail

getX

public int getX()

Returns the x coordinate of this desktop, which is always 0.

Specified by:

getX in interface Renderable

Returns:

the x coordinate of this desktop

getY

public int getY()

Returns the y coordinate of this desktop, which is always 0.

Specified by:

getY in interface Renderable

Returns:

the y coordinate of this desktop

getWidth

public int getWidth()

Returns the width of this desktop: it is equal to the width of its associated display.

Specified by:

getWidth in interface Renderable

Returns:

the width of this desktop

getHeight

public int getHeight()

Returns the height of this desktop: it is equal to the height of its associated display.

Specified by:

getHeight in interface Renderable

Returns:

the height of this desktop

repaint

public void repaint(int x,
                    int y,
                    int width,
                    int height)

Requests a repaint of a zone of this desktop.

This method returns immediately, the repaint of the desktop is performed asynchronously.
If the desktop is not shown, nothing is done.

Specified by:

repaint in interface Renderable

Parameters:

x - the relative x coordinate of the area to repaint.

y - the relative y coordinate of the area to repaint.

width - the width of the area to repaint.

height - the height of the area to repaint.

render

public void render(ej.microui.display.GraphicsContext g)

Description copied from interface: Renderable

Renders the renderable on the given graphics context.

Specified by:

render in interface Renderable

Parameters:

g - the graphics context to be used to draw the renderable.

getActivePanel

public Panel getActivePanel()

Gets this desktop's active panel. The active panel is the last in the panel's list.

Returns:

the desktop's active panel, or null if none

setActivePanel

public void setActivePanel(Panel panel)
                    throws java.lang.NullPointerException,
                           java.lang.IllegalArgumentException

Sets the specified panel as the active one on this desktop.

Parameters:

panel - the panel to set active

Throws:

java.lang.NullPointerException - if the specified panel is null

java.lang.IllegalArgumentException - if the specified panel is not on this desktop

See Also:

getActivePanel()

getPanels

public Panel[] getPanels()

Gets the list of the panels being shown on this desktop.
A panel is added to this list when it executes Panel.show(Desktop) and removed when it executes Panel.hide().

Returns:

the list of the panels on this desktop

revalidate

public void revalidate()

Lays out all the hierarchy of this desktop.

It performs the method validate() asynchronously. Therefore this method does not block until the validation of the hierarchy is done.

Nothing is done if it is not shown.

Since:

1.0

See Also:

validate()

validate

public void validate()

Lays out all the hierarchy of this desktop.

Since:

1.0

See Also:

Panel.validate()

showNotify

public void showNotify()

The desktop is visible on its display.

Notifies its children panels that they are shown.

Ask for a revalidation of the entire desktop.

Specified by:

showNotify in interface Renderable

Overrides:

showNotify in class ej.microui.display.Displayable

Since:

1.0

See Also:

revalidate()

hideNotify

public void hideNotify()

The desktop is hidden from its display.

Notifies its children panels that they are hidden.

Specified by:

hideNotify in interface Renderable

Overrides:

hideNotify in class ej.microui.display.Displayable

Since:

1.0

getController

public ej.microui.util.EventHandler getController()

Specified by:

getController in class ej.microui.display.Displayable

setEventHandler

public void setEventHandler(ej.microui.util.EventHandler eventHandler)

Description copied from interface: Renderable

Sets the event handler.

Specified by:

setEventHandler in interface Renderable

Parameters:

eventHandler - the event handler to set.

See Also:

Renderable.handleEvent(int)

getEventHandler

public ej.microui.util.EventHandler getEventHandler()

Description copied from interface: Renderable

Gets the event handler.

Specified by:

getEventHandler in interface Renderable

Returns:

the event handler.

See Also:

Renderable.handleEvent(int)

handleEvent

public boolean handleEvent(int event)

Called by the system if no widget nor panel in the focused hierarchy has consumed the event.

Specified by:

handleEvent in interface Renderable

Parameters:

event - the event to handle

Returns:

true if the desktop has consumed the event, false otherwise

Since:

0.9

paint

public final void paint(ej.microui.display.GraphicsContext g)

Specified by:

paint in class ej.microui.display.Displayable

panelAt

public Panel panelAt(int x,
                     int y)

Gets the panel at the specified position.

Parameters:

x - the x coordinate to search at.

y - the y coordinate to search at.

Returns:

the panel at the specified location or null if none.

Since:

2.0

isAccessible

public boolean isAccessible(Panel panel)

Checks whether or not a panel is accessible to the user.

A panel is accessible if:

1. there is no dialog,
2. or the panel is the dialog on the top.

Parameters:

panel - the panel to check.

Returns:

true if the panel is accessible, false otherwise.

Since:

2.0