jview
Class BlinkImage

java.lang.Object
  java.awt.Image
      jview.BlinkImage

All Implemented Interfaces:

ActionListener, EventListener

public class BlinkImage
extends Image
implements ActionListener

A blinking image is used to allow blinking of icons or other images. This class can work also on parts of a graphics object, so it is possible to differently animate compunds of the entire component.

This class expects two images, the on and off image in its constructor, along with the swing component within which this image animation should be drwan. If the user wants to specify a different location than (0,0) for the image to be displayed, call the method setUpperLeftCorner(java.awt.Point) prior to starting the blinker with startBlink(). Because this implementation uses a swing timer to perform the blinking, the time intervall between the on and off state are equal.

Nested Class Summary

static class

BlinkImage.Test For testing.

Field Summary

private boolean	afteroff If true we draw the off image after animation, otherwise on.
private int	count The current invocation number in the action performed method.
private boolean	current True if the on image should be isplayed.
private static int	DEFBLINK The default blinking time, in ms.
private boolean	draw A boolean determining whether the blinker is drawing.
private Timer	flash The timer used to produce action events for the blinking.
private int	frequency The number of action events to drop for the next frame.
private Image	off The off-image.
private Point	offset The offset where to draw the blinking image.
private Image	on The on-image.
private Component	pane The component where to get the graphics object from.
private boolean	prioron If true we draw the on image prior to animation start, otherwise off.
private Dimension	size The dimension of the images.

Fields inherited from class java.awt.Image

accelerationPriority, SCALE_AREA_AVERAGING, SCALE_DEFAULT, SCALE_FAST, SCALE_REPLICATE, SCALE_SMOOTH, UndefinedProperty

Constructor Summary

BlinkImage(Image high, Image low, Component observer, Timer time)
Creates a new blinking image instance.

BlinkImage(Image high, Image low, int delay, Component observer, Timer time)
Creates a new blinking image instance.

Method Summary

void	actionPerformed(ActionEvent ae) Does the blinking.
void	flush()
private Image	getActualImage() Returns the actual image.
Graphics	getGraphics()
int	getHeight(ImageObserver observer)
Object	getProperty(String name, ImageObserver observer)
Image	getScaledInstance(int width, int height, int hints)
ImageProducer	getSource()
Point	getUpperLeftCorner() Returns the offset.
int	getWidth(ImageObserver observer)
boolean	isActive() Queries this component whether it is drawing.
void	setBlinkIntervall(int delay) Sets the blinking intervall.
void	setPriorAndAfterState(boolean onprior, boolean offafter) Determines which images are to displayed prior to the animation and after stopping it.
void	setUpperLeftCorner(Point ul) Sets an offset where this blinking image should be displayed on the observer's graphics object.
void	startBlink() Starts the blinking.
void	stopBlink() Stops the blinking.

Methods inherited from class java.awt.Image

getAccelerationPriority, getCapabilities, setAccelerationPriority

Methods inherited from class java.lang.Object

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

Field Detail

DEFBLINK

private static final int DEFBLINK

The default blinking time, in ms.

See Also:

Constant Field Values

on

private Image on

The on-image.

off

private Image off

The off-image. This is in most cases the background of the component.

current

private boolean current

True if the on image should be isplayed.

flash

private Timer flash

The timer used to produce action events for the blinking.

pane

private Component pane

The component where to get the graphics object from.

offset

private Point offset

The offset where to draw the blinking image. Defaults to 0,0 .

size

private Dimension size

The dimension of the images.

draw

private boolean draw

A boolean determining whether the blinker is drawing.

prioron

private boolean prioron

If true we draw the on image prior to animation start, otherwise off.

afteroff

private boolean afteroff

If true we draw the off image after animation, otherwise on.

frequency

private int frequency

The number of action events to drop for the next frame.

count

private int count

The current invocation number in the action performed method.

Constructor Detail

BlinkImage

public BlinkImage(Image high,
                  Image low,
                  Component observer,
                  Timer time)

Creates a new blinking image instance. The image does not blink until the method startBlink() is explicedly called.

Parameters:

high - The image to display in the on state or prior to start.

low - The image to display in the off state or after stop.

observer - The component whose graphics is used to draw the image.

time - The timer to allow synchronous blinking for multiple blinking images.

BlinkImage

public BlinkImage(Image high,
                  Image low,
                  int delay,
                  Component observer,
                  Timer time)

Creates a new blinking image instance. The delay time between on and off states is explicetly given and matched to the timer's delay. The image does not blink until the method startBlink() is explicedly called.

Parameters:

high - The image to display in the on state or prior to start.

low - The image to display in the off state or after stop.

observer - The component whose graphics is used to draw the image.

delay - The target blinking delay. If not a straight multiple of the timer's delay, round to closest multiple.

time - The timer to allow synchronous blinking for multiple blinking images.

Method Detail

setPriorAndAfterState

public void setPriorAndAfterState(boolean onprior,
                                  boolean offafter)

Determines which images are to displayed prior to the animation and after stopping it. Per default, the on image is displayed before start and the off after stopping.

Parameters:

onprior - If false, use the off image before animation

offafter - If false, use the on image after animation.

setUpperLeftCorner

public void setUpperLeftCorner(Point ul)

Sets an offset where this blinking image should be displayed on the observer's graphics object.

getUpperLeftCorner

public Point getUpperLeftCorner()

Returns the offset.

setBlinkIntervall

public void setBlinkIntervall(int delay)

Sets the blinking intervall.

startBlink

public void startBlink()

Starts the blinking.

stopBlink

public void stopBlink()

Stops the blinking.

isActive

public boolean isActive()

Queries this component whether it is drawing.

actionPerformed

public void actionPerformed(ActionEvent ae)

Does the blinking.

Specified by:

actionPerformed in interface ActionListener

flush

public void flush()

Overrides:

flush in class Image

getGraphics

public Graphics getGraphics()

Specified by:

getGraphics in class Image

getHeight

public int getHeight(ImageObserver observer)

Specified by:

getHeight in class Image

getProperty

public Object getProperty(String name,
                          ImageObserver observer)

Specified by:

getProperty in class Image

getScaledInstance

public Image getScaledInstance(int width,
                               int height,
                               int hints)

Overrides:

getScaledInstance in class Image

getSource

public ImageProducer getSource()

Specified by:

getSource in class Image

getWidth

public int getWidth(ImageObserver observer)

Specified by:

getWidth in class Image

getActualImage

private Image getActualImage()

Returns the actual image.