jcontrol.ui.vole
Class Component

java.lang.Object
  jcontrol.ui.vole.Component

Direct Known Subclasses:

AnalogClock, AnalogMeter, BarMeter, Border, Button, CheckBox, ComboBox, Container, Diagram, DigitalMeter, FanMeter, Histogram, Label, List, Menu, NumberChooser, RadioButton, RockerSwitch, ScrollBar, SevenSegmentMeter, Slider, TextArea, TextScroller, Thermometer

public abstract class Component
extends Object

Component is the base class for VOLE user interface objects.

(c) Copyright 2003-2007 DOMOLOGIC GmbH

Field Summary

protected static java.util.Vector	eventQueue Event queue for this component
protected static Component	focusOwner Current focus owner (global flag)
protected Resource	font A font resource for drawing text.
protected Graphics	g The graphic context
protected int	height The control's height
protected ActionListener	listener ActionListener, called on ActionEvents
protected Container	parent The parent of the control.
protected boolean	visible Our visibility
protected int	width The control's width
protected int	x The control's x location
protected int	y The control's y location

Constructor Summary

Component()

Method Summary

int[]	getBounds() Returns the current bounds of this component as array of int.
Container	getParent() Return the parent container if available.
boolean	isVisible() Get visible state.
void	onActionEvent(ActionEvent e) ActionEvent event handler.
boolean	onKeyEvent(KeyEvent e) Keyboard event handler.
void	paint() Paints this component.
void	remove() Removes this component and draws a rectangle in the background color.
void	removeFocus() Removes the focus from this Component.
void	requestFocus() Sets the focus to this Component.
void	setBounds(int x, int y, int width, int height) Set the dimensions of this component.
void	setFont(Resource font) Sets the font for this component.
void	setGraphics(Graphics g) This method is called to set the main Display context for this component.
void	setParent(Container parent) Sets the parent Container
void	setVisible(boolean visible) Turns the component visible or invisible.
boolean	transferFocus() Transfers the focus to the next component.
void	validate() Calculate and set the preferred size of this Component.

Methods inherited from class java.lang.Object

clone, equals, getClass, notifyAll, toString, wait

Field Detail

x

protected int x

The control's x location

y

protected int y

The control's y location

width

protected int width

The control's width

height

protected int height

The control's height

parent

protected Container parent

The parent of the control.

g

protected Graphics g

The graphic context

visible

protected boolean visible

Our visibility

font

protected Resource font

A font resource for drawing text. Components are self-responsible for making use of this resource.

listener

protected ActionListener listener

ActionListener, called on ActionEvents

focusOwner

protected static Component focusOwner

Current focus owner (global flag)

eventQueue

protected static java.util.Vector eventQueue

Event queue for this component

Constructor Detail

Component

public Component()

Method Detail

onKeyEvent

public boolean onKeyEvent(KeyEvent e)

Keyboard event handler. Overwrite this method if you want to receive key events.

Parameters:

e - the KeyEvent

Returns:

If this method returns true, the KeyEvent is handled by the super Container.

onActionEvent

public void onActionEvent(ActionEvent e)

ActionEvent event handler. Overwrite this method if you want to receive ActionEvents.

Parameters:

e - the ActionEvent

getParent

public Container getParent()

Return the parent container if available.

Returns:

the parent container

setParent

public void setParent(Container parent)

Sets the parent Container

Parameters:

parent - the Container to be the parent Object

transferFocus

public boolean transferFocus()

Transfers the focus to the next component.

Returns:

true, if the focus was transferred successfully.

removeFocus

public void removeFocus()

Removes the focus from this Component.

requestFocus

public void requestFocus()

Sets the focus to this Component.

setGraphics

public void setGraphics(Graphics g)

This method is called to set the main Display context for this component. Normally, this is done only for the top-level container, then, all child components are set automatically.

Parameters:

g - the Display

remove

public void remove()

Removes this component and draws a rectangle in the background color.

paint

public void paint()

Paints this component.

setVisible

public void setVisible(boolean visible)

Turns the component visible or invisible.

Parameters:

onoff - true, if visible - false, otherwise

isVisible

public boolean isVisible()

Get visible state.

Returns:

boolean visible state

setBounds

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

Set the dimensions of this component. The component is repainted automatically.

Parameters:

x - x coordinate of the upper left corner

y - y coordinate of the upper left corner

width - The width of this component

height - The height of this component

getBounds

public int[] getBounds()

Returns the current bounds of this component as array of int.

Returns:

int[] The bounds of this component, ordered {x, y, width, height}.

setFont

public void setFont(Resource font)

Sets the font for this component.

Parameters:

font - The new font.

validate

public void validate()

Calculate and set the preferred size of this Component. The calculated values depend on various parameters like font size and drawing styles. After calculation, the component's paint- method should be invoked.