org.eclipse.core.runtime.dynamichelpers

Interface IExtensionTracker

All Known Implementing Classes:

ExtensionTracker

public interface IExtensionTracker

An extension tracker keeps associations between extensions and their derived objects on an extension basis. All extensions being added in a tracker will automatically be removed when the extension is uninstalled from the registry. Users interested in extension removal can register a handler that will let them know when an object is being removed.

This interface can be used without OSGi running.

This interface is not intended to be implemented by clients.

Since:

3.1

Field Summary

Fields

Modifier and Type	Field and Description
static int	REF_SOFT Constant for soft reference holding.
static int	REF_STRONG Constant for strong (normal) reference holding.
static int	REF_WEAK Constant for weak reference holding.

Method Summary

Modifier and Type	Method and Description
void	close() Close the tracker.
java.lang.Object[]	getObjects(IExtension extension) Return all the objects that have been associated with the given extension.
void	registerHandler(IExtensionChangeHandler handler, IFilter filter) Register an extension change handler with this tracker using the given filter.
void	registerObject(IExtension extension, java.lang.Object object, int referenceType) Create an association between the given extension and the given object.
void	unregisterHandler(IExtensionChangeHandler handler) Unregister the given extension change handler previously registered with this tracker.
java.lang.Object[]	unregisterObject(IExtension extension) Remove all the objects associated with the given extension.
void	unregisterObject(IExtension extension, java.lang.Object object) Remove an association between the given extension and the given object.

Field Detail

REF_STRONG

static final int REF_STRONG

Constant for strong (normal) reference holding. Value 1.

REF_SOFT

static final int REF_SOFT

Constant for soft reference holding. Value 2.

REF_WEAK

static final int REF_WEAK

Constant for weak reference holding. Value 3.

Method Detail

registerHandler

void registerHandler(IExtensionChangeHandler handler,
                     IFilter filter)

Register an extension change handler with this tracker using the given filter.

Parameters:

handler - the handler to be registered

filter - the filter to use to choose interesting changes

unregisterHandler

void unregisterHandler(IExtensionChangeHandler handler)

Unregister the given extension change handler previously registered with this tracker.

Parameters:

handler - the handler to be unregistered

registerObject

void registerObject(IExtension extension,
                    java.lang.Object object,
                    int referenceType)

Create an association between the given extension and the given object. The referenceType indicates how strongly the object is being kept in memory. There is 3 possible values: REF_STRONG, REF_SOFT, REF_WEAK.

Parameters:

extension - the extension

object - the object to associate with the extension

referenceType - one of REF_STRONG, REF_SOFT, REF_WEAK

See Also:

REF_STRONG, REF_SOFT, REF_WEAK

unregisterObject

void unregisterObject(IExtension extension,
                      java.lang.Object object)

Remove an association between the given extension and the given object.

Parameters:

extension - the extension under which the object has been registered

object - the object to unregister

unregisterObject

java.lang.Object[] unregisterObject(IExtension extension)

Remove all the objects associated with the given extension. Return the removed objects.

Parameters:

extension - the extension for which the objects are removed

Returns:

the objects that were associated with the extension

getObjects

java.lang.Object[] getObjects(IExtension extension)

Return all the objects that have been associated with the given extension. All objects registered strongly will be return unless they have been unregistered. The objects registered softly or weakly may not be returned if they have been garbage collected. Return an empty array if no associations exist.

Parameters:

extension - the extension for which the object must be returned

Returns:

the array of associated objects

close

void close()

Close the tracker. All registered objects are freed and all handlers are being automatically removed.