org.zaval.lw
Interface LwDesktop

All Superinterfaces:

Layoutable, LayoutContainer, LwComponent, LwContainer, Validationable

All Known Implementing Classes:

J2SEDesktop

public interface LwDesktop

extends LwContainer

This interface is top-level container for all other lightweight components. The main purpose of the interface to provide abstraction level that binds the library with a concrete GUI implementation. Every lightweight component is bound with a desktop container. Use the LwToolkit.getDesktop method to get a desktop for the specified lightweight component. The desktop consists of layers. Layer is a special light weight container that is a child component of the desktop. It is impossible to add a none-layer component to the desktop. Use the getRootLayer method to get the root layer. The layer should be used if you want to add a light weight component on the desktop surface. The other available layer is the windows layer. The layer provides functionality to work with internal frames. The top-level layer is a popup menu layer.

Method Summary
void	activate(boolean b)           Invoked whenever the desktop has been activated or de-activated.
java.awt.Image	createImage(int w, int h)           Creates an off-screen image to be used for double buffering with the specified width and height.
java.awt.Rectangle	getDA()           Gets the dirty area of the component.
java.awt.Graphics	getGraphics()           Gets a graphics context for this desktop.
LwLayer	getLayer(java.lang.Object id)           Gets the layer by the specified id.
java.lang.Object	getNCanvas()           Gets the native component where the desktop layer "lives".
java.lang.Object	getProperty(int id)           Gets the value for the specified property.
LwLayer	getRootLayer()           Gets the root layer that should be used to add a light weight component on the desktop surface.
void	setProperty(int id, java.lang.Object value)           Sets the value for the specified property.

 

Methods inherited from interface org.zaval.lw.LwContainer

add, add, getLwLayout, indexOf, insert, isInvalidatedByChild, paintOnTop, remove, removeAll, setLwLayout

 

Methods inherited from interface org.zaval.lw.LwComponent

canHaveFocus, getBackground, getLwComponentAt, getLwParent, getOrigin, getViewMan, getVisiblePart, isEnabled, isOpaque, paint, repaint, repaint, repaint, setBackground, setEnabled, setInsets, setLwParent, setOpaque, setViewMan, setVisible, update

 

Methods inherited from interface org.zaval.lw.Layoutable

getBounds, getHeight, getInsets, getLocation, getPreferredSize, getSize, getWidth, getX, getY, isVisible, setLocation, setSize

 

Methods inherited from interface org.zaval.util.Validationable

invalidate, isValid, validate

 

Methods inherited from interface org.zaval.lw.LayoutContainer

count, get, getLayoutOffset

 

Method Detail

getNCanvas

public java.lang.Object getNCanvas()

Gets the native component where the desktop layer "lives". For example, in a case the J2SE LwVCL version the method returns a java.awt.Panel instance as the native component.

Returns:

a native component.

getRootLayer

public LwLayer getRootLayer()

Gets the root layer that should be used to add a light weight component on the desktop surface.

Returns:

a root layer.

getLayer

public LwLayer getLayer(java.lang.Object id)

Gets the layer by the specified id. There are two layers available by the "root" and "win" IDs.

Parameters:

id - the specified id.

Returns:

a layer.

getGraphics

public java.awt.Graphics getGraphics()

Gets a graphics context for this desktop. This is adaptive method and it is used to bind native GUI implementation with the components of the library.

Returns:

a graphics context.

createImage

public java.awt.Image createImage(int w,
                                  int h)

Creates an off-screen image to be used for double buffering with the specified width and height. This is adaptive method and it is used to bind native GUI implementation with the components of the library.

Parameters:

w - the specified image width.

h - the specified image height.

Returns:

an off-screen image.

getProperty

public java.lang.Object getProperty(int id)

Gets the value for the specified property.

Parameters:

id - the specified property id.

Returns:

a value of the property.

setProperty

public void setProperty(int id,
                        java.lang.Object value)

Sets the value for the specified property.

Parameters:

id - the specified property id.

value - the specified property value.

getDA

public java.awt.Rectangle getDA()

Gets the dirty area of the component. The method is used to store and update the desktop dirty area (this is the area that should be updated).

Returns:

a dirty area.

activate

public void activate(boolean b)

Invoked whenever the desktop has been activated or de-activated.

Parameters:

b - the flag specifies if the desktop has been activated or de-activated. The argument value is true if the desktop has been activated.