java.awt
Class MediaTracker

java.lang.Object
  |
  +--java.awt.MediaTracker

All Implemented Interfaces:

Serializable

public class MediaTracker

extends Object

implements Serializable

Safe:

See Also:

Serialized Form

Field Summary

static int	ABORTED Enabled: Flag indicating that the downloading of media was aborted.
static int	COMPLETE Enabled: Flag indicating that the downloading of media was completed successfully.
(package private) static int	DONE
static int	ERRORED Enabled: Flag indicating that the downloading of media encountered an error.
(package private) MediaEntry	head The head of the list of Images that is being tracked by the MediaTracker.
static int	LOADING Enabled: Flag indicating that media is currently being loaded.
private static long	serialVersionUID
(package private) Component	target A given Component that will be tracked by a media tracker where the image will eventually be drawn.

Constructor Summary

MediaTracker(Component comp)
Enabled: Creates a media tracker to track images for a given component.

Method Summary

void	addImage(Image image, int id) Enabled: Adds an image to the list of images being tracked by this media tracker.
void	addImage(Image image, int id, int w, int h) Enabled: Adds a scaled image to the list of images being tracked by this media tracker.
boolean	checkAll() Enabled: Checks to see if all images being tracked by this media tracker have finished loading.
boolean	checkAll(boolean load) Enabled: Checks to see if all images being tracked by this media tracker have finished loading.
private boolean	checkAll(boolean load, boolean verify)
boolean	checkID(int id) Enabled: Checks to see if all images tracked by this media tracker that are tagged with the specified identifier have finished loading.
boolean	checkID(int id, boolean load) Enabled: Checks to see if all images tracked by this media tracker that are tagged with the specified identifier have finished loading.
private boolean	checkID(int id, boolean load, boolean verify)
Object[]	getErrorsAny() Enabled: Returns a list of all media that have encountered an error.
Object[]	getErrorsID(int id) Enabled: Returns a list of media with the specified ID that have encountered an error.
boolean	isErrorAny() Enabled: Checks the error status of all of the images.
boolean	isErrorID(int id) Enabled: Checks the error status of all of the images tracked by this media tracker with the specified identifier.
void	removeImage(Image image) Enabled: Removes the specified image from this media tracker.
void	removeImage(Image image, int id) Enabled: Removes the specified image from the specified tracking ID of this media tracker.
void	removeImage(Image image, int id, int width, int height) Enabled: Removes the specified image with the specified width, height, and ID from this media tracker.
(package private) void	setDone()
int	statusAll(boolean load) Enabled: Calculates and returns the bitwise inclusive OR of the status of all media that are tracked by this media tracker.
private int	statusAll(boolean load, boolean verify)
int	statusID(int id, boolean load) Enabled: Calculates and returns the bitwise inclusive OR of the status of all media with the specified identifier that are tracked by this media tracker.
private int	statusID(int id, boolean load, boolean verify)
void	waitForAll() Enabled: Starts loading all images tracked by this media tracker.
boolean	waitForAll(long ms) Enabled: Starts loading all images tracked by this media tracker.
void	waitForID(int id) Enabled: Starts loading all images tracked by this media tracker with the specified identifier.
boolean	waitForID(int id, long ms) Enabled: Starts loading all images tracked by this media tracker with the specified identifier.

Methods inherited from class java.lang.Object

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

Field Detail

target

Component target

A given Component that will be tracked by a media tracker where the image will eventually be drawn.

See Also:

MediaTracker()

head

MediaEntry head

The head of the list of Images that is being tracked by the MediaTracker.

See Also:

addImage(), removeImage()

serialVersionUID

private static final long serialVersionUID

LOADING

public static final int LOADING

Enabled: Flag indicating that media is currently being loaded.

See Also:

java.awt.MediaTracker#statusAll, java.awt.MediaTracker#statusID

ABORTED

public static final int ABORTED

Enabled: Flag indicating that the downloading of media was aborted.

See Also:

java.awt.MediaTracker#statusAll, java.awt.MediaTracker#statusID

ERRORED

public static final int ERRORED

Enabled: Flag indicating that the downloading of media encountered an error.

See Also:

java.awt.MediaTracker#statusAll, java.awt.MediaTracker#statusID

COMPLETE

public static final int COMPLETE

Enabled: Flag indicating that the downloading of media was completed successfully.

See Also:

java.awt.MediaTracker#statusAll, java.awt.MediaTracker#statusID

DONE

static final int DONE

Constructor Detail

MediaTracker

public MediaTracker(Component comp)

Enabled: Creates a media tracker to track images for a given component.

Parameters:

comp - the component on which the images will eventually be drawn

Method Detail

addImage

public void addImage(Image image,
                     int id)

Enabled: Adds an image to the list of images being tracked by this media tracker. The image will eventually be rendered at its default (unscaled) size.

Parameters:

image - the image to be tracked

id - an identifier used to track this image

addImage

public void addImage(Image image,
                     int id,
                     int w,
                     int h)

Enabled: Adds a scaled image to the list of images being tracked by this media tracker. The image will eventually be rendered at the indicated width and height.

Parameters:

image - the image to be tracked

id - an identifier that can be used to track this image

w - the width at which the image is rendered

h - the height at which the image is rendered

checkAll

public boolean checkAll()

Enabled: Checks to see if all images being tracked by this media tracker have finished loading.

This method does not start loading the images if they are not already loading.

If there is an error while loading or scaling an image, then that image is considered to have finished loading. Use the isErrorAny or isErrorID methods to check for errors.

Returns:

true if all images have finished loading, have been aborted, or have encountered an error; false otherwise

See Also:

java.awt.MediaTracker#checkAll(boolean), java.awt.MediaTracker#checkID, java.awt.MediaTracker#isErrorAny, java.awt.MediaTracker#isErrorID

checkAll

public boolean checkAll(boolean load)

Enabled: Checks to see if all images being tracked by this media tracker have finished loading.

If the value of the load flag is true, then this method starts loading any images that are not yet being loaded.

If there is an error while loading or scaling an image, that image is considered to have finished loading. Use the isErrorAny and isErrorID methods to check for errors.

Parameters:

load - if true, start loading any images that are not yet being loaded

Returns:

true if all images have finished loading, have been aborted, or have encountered an error; false otherwise

See Also:

java.awt.MediaTracker#checkID, java.awt.MediaTracker#checkAll(), java.awt.MediaTracker#isErrorAny(), java.awt.MediaTracker#isErrorID(int)

checkAll

private boolean checkAll(boolean load,
                         boolean verify)

isErrorAny

public boolean isErrorAny()

Enabled: Checks the error status of all of the images.

Returns:

true if any of the images tracked by this media tracker had an error during loading; false otherwise

See Also:

java.awt.MediaTracker#isErrorID, java.awt.MediaTracker#getErrorsAny

getErrorsAny

public Object[] getErrorsAny()

Enabled: Returns a list of all media that have encountered an error.

Returns:

an array of media objects tracked by this media tracker that have encountered an error, or null if there are none with errors

See Also:

java.awt.MediaTracker#isErrorAny, java.awt.MediaTracker#getErrorsID

waitForAll

public void waitForAll()
                throws InterruptedException

Enabled: Starts loading all images tracked by this media tracker. This method waits until all the images being tracked have finished loading.

If there is an error while loading or scaling an image, then that image is considered to have finished loading. Use the isErrorAny or isErrorID methods to check for errors.

InterruptedException

See Also:

java.awt.MediaTracker#waitForID(int), java.awt.MediaTracker#waitForAll(long), java.awt.MediaTracker#isErrorAny, java.awt.MediaTracker#isErrorID

waitForAll

public boolean waitForAll(long ms)
                   throws InterruptedException

Enabled: Starts loading all images tracked by this media tracker. This method waits until all the images being tracked have finished loading, or until the length of time specified in milliseconds by the ms argument has passed.

If there is an error while loading or scaling an image, then that image is considered to have finished loading. Use the isErrorAny or isErrorID methods to check for errors.

Parameters:

ms - the number of milliseconds to wait for the loading to complete

Returns:

true if all images were successfully loaded; false otherwise

InterruptedException

See Also:

java.awt.MediaTracker#waitForID(int), java.awt.MediaTracker#waitForAll(long), java.awt.MediaTracker#isErrorAny, java.awt.MediaTracker#isErrorID

statusAll

public int statusAll(boolean load)

Enabled: Calculates and returns the bitwise inclusive OR of the status of all media that are tracked by this media tracker.

Possible flags defined by the MediaTracker class are LOADING, ABORTED, ERRORED, and COMPLETE. An image that hasn't started loading has zero as its status.

If the value of load is true, then this method starts loading any images that are not yet being loaded.

Parameters:

load - if true, start loading any images that are not yet being loaded

Returns:

the bitwise inclusive OR of the status of all of the media being tracked

See Also:

java.awt.MediaTracker#statusID(int, boolean), java.awt.MediaTracker#LOADING, java.awt.MediaTracker#ABORTED, java.awt.MediaTracker#ERRORED, java.awt.MediaTracker#COMPLETE

statusAll

private int statusAll(boolean load,
                      boolean verify)

checkID

public boolean checkID(int id)

Enabled: Checks to see if all images tracked by this media tracker that are tagged with the specified identifier have finished loading.

This method does not start loading the images if they are not already loading.

If there is an error while loading or scaling an image, then that image is considered to have finished loading. Use the isErrorAny or isErrorID methods to check for errors.

Parameters:

id - the identifier of the images to check

Returns:

true if all images have finished loading, have been aborted, or have encountered an error; false otherwise

See Also:

java.awt.MediaTracker#checkID(int, boolean), java.awt.MediaTracker#checkAll(), java.awt.MediaTracker#isErrorAny(), java.awt.MediaTracker#isErrorID(int)

checkID

public boolean checkID(int id,
                       boolean load)

Enabled: Checks to see if all images tracked by this media tracker that are tagged with the specified identifier have finished loading.

If the value of the load flag is true, then this method starts loading any images that are not yet being loaded.

If there is an error while loading or scaling an image, then that image is considered to have finished loading. Use the isErrorAny or isErrorID methods to check for errors.

Parameters:

id - the identifier of the images to check

load - if true, start loading any images that are not yet being loaded

Returns:

true if all images have finished loading, have been aborted, or have encountered an error; false otherwise

See Also:

java.awt.MediaTracker#checkID(int, boolean), java.awt.MediaTracker#checkAll(), java.awt.MediaTracker#isErrorAny(), java.awt.MediaTracker#isErrorID(int)

checkID

private boolean checkID(int id,
                        boolean load,
                        boolean verify)

isErrorID

public boolean isErrorID(int id)

Enabled: Checks the error status of all of the images tracked by this media tracker with the specified identifier.

Parameters:

id - the identifier of the images to check

Returns:

true if any of the images with the specified identifier had an error during loading; false otherwise

See Also:

java.awt.MediaTracker#isErrorAny, java.awt.MediaTracker#getErrorsID

getErrorsID

public Object[] getErrorsID(int id)

Enabled: Returns a list of media with the specified ID that have encountered an error.

Parameters:

id - the identifier of the images to check

Returns:

an array of media objects tracked by this media tracker with the specified identifier that have encountered an error, or null if there are none with errors

See Also:

java.awt.MediaTracker#isErrorID, java.awt.MediaTracker#isErrorAny, java.awt.MediaTracker#getErrorsAny

waitForID

public void waitForID(int id)
               throws InterruptedException

Enabled: Starts loading all images tracked by this media tracker with the specified identifier. This method waits until all the images with the specified identifier have finished loading.

If there is an error while loading or scaling an image, then that image is considered to have finished loading. Use the isErrorAny and isErrorID methods to check for errors.

Parameters:

id - the identifier of the images to check

InterruptedException

See Also:

java.awt.MediaTracker#waitForAll, java.awt.MediaTracker#isErrorAny(), java.awt.MediaTracker#isErrorID(int)

waitForID

public boolean waitForID(int id,
                         long ms)
                  throws InterruptedException

Enabled: Starts loading all images tracked by this media tracker with the specified identifier. This method waits until all the images with the specified identifier have finished loading, or until the length of time specified in milliseconds by the ms argument has passed.

If there is an error while loading or scaling an image, then that image is considered to have finished loading. Use the statusID, isErrorID, and isErrorAny methods to check for errors.

Parameters:

id - the identifier of the images to check

ms - the length of time, in milliseconds, to wait for the loading to complete

InterruptedException

See Also:

java.awt.MediaTracker#waitForAll, java.awt.MediaTracker#waitForID(int), java.awt.MediaTracker#statusID, java.awt.MediaTracker#isErrorAny(), java.awt.MediaTracker#isErrorID(int)

statusID

public int statusID(int id,
                    boolean load)

Enabled: Calculates and returns the bitwise inclusive OR of the status of all media with the specified identifier that are tracked by this media tracker.

Possible flags defined by the MediaTracker class are LOADING, ABORTED, ERRORED, and COMPLETE. An image that hasn't started loading has zero as its status.

If the value of load is true, then this method starts loading any images that are not yet being loaded.

Parameters:

id - the identifier of the images to check

load - if true, start loading any images that are not yet being loaded

Returns:

the bitwise inclusive OR of the status of all of the media with the specified identifier that are being tracked

See Also:

java.awt.MediaTracker#statusAll(boolean), java.awt.MediaTracker#LOADING, java.awt.MediaTracker#ABORTED, java.awt.MediaTracker#ERRORED, java.awt.MediaTracker#COMPLETE

statusID

private int statusID(int id,
                     boolean load,
                     boolean verify)

removeImage

public void removeImage(Image image)

Enabled: Removes the specified image from this media tracker. All instances of the specified image are removed, regardless of scale or ID.

Parameters:

image - the image to be removed

Since:

JDK1.1

See Also:

java.awt.MediaTracker#removeImage(java.awt.Image, int), java.awt.MediaTracker#removeImage(java.awt.Image, int, int, int)

removeImage

public void removeImage(Image image,
                        int id)

Enabled: Removes the specified image from the specified tracking ID of this media tracker. All instances of Image being tracked under the specified ID are removed regardless of scale.

Parameters:

image - the image to be removed

id - the tracking ID frrom which to remove the image

Since:

JDK1.1

See Also:

java.awt.MediaTracker#removeImage(java.awt.Image), java.awt.MediaTracker#removeImage(java.awt.Image, int, int, int)

removeImage

public void removeImage(Image image,
                        int id,
                        int width,
                        int height)

Enabled: Removes the specified image with the specified width, height, and ID from this media tracker. Only the specified instance (with any duplicates) is removed.

Parameters:

image - the image to be removed

id - the tracking ID from which to remove the image

width - the width to remove (-1 for unscaled)

height - the height to remove (-1 for unscaled)

Since:

JDK1.1

See Also:

java.awt.MediaTracker#removeImage(java.awt.Image), java.awt.MediaTracker#removeImage(java.awt.Image, int)

setDone

void setDone()