org.eclipse.core.commands.contexts
Class ContextManager
java.lang.Object
org.eclipse.core.commands.common.EventManager
org.eclipse.core.commands.common.HandleObjectManager
org.eclipse.core.commands.contexts.ContextManager
-
All Implemented Interfaces:
-
IContextListener
-
public final class ContextManager
- extends
HandleObjectManager
- implements
IContextListener
A context manager tracks the sets of defined and enabled contexts within the
application. The manager sends notification events to listeners when these
sets change. It is also possible to retrieve any given context with its
identifier.
This class is not intended to be extended by clients.
-
Since:
- 3.1
Field Summary
|
static boolean
|
DEBUG
This flag can be set to true if the context manager should
print information to System.out when certain boundary
conditions occur. |
Methods inherited from class java.lang.
Object
|
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
|
DEBUG
public static boolean DEBUG
- This flag can be set to
true
if the context manager should
print information to System.out
when certain boundary
conditions occur.
ContextManager
public ContextManager()
deferUpdates
public void deferUpdates(boolean defer)
- Informs the manager that a batch operation has started.
Note: You must insure that if you call
deferUpdates(true)
that nothing in your batched operation
will prevent the matching call to deferUpdates(false)
.
-
-
-
Parameters:
-
defer
- true when starting a batch operation false when ending the
operation -
Since:
- 3.5
addActiveContext
public final void addActiveContext(
String contextId)
- Activates a context in this context manager.
-
-
-
Parameters:
-
contextId
- The identifier of the context to activate; must not be
null
.
addContextManagerListener
public final void addContextManagerListener(
IContextManagerListener listener)
- Adds a listener to this context manager. The listener will be notified
when the set of defined contexts changes. This can be used to track the
global appearance and disappearance of contexts.
-
-
-
Parameters:
-
listener
- The listener to attach; must not be null
.
contextChanged
public final void contextChanged(
ContextEvent contextEvent)
-
Description copied from interface:
IContextListener
- Notifies that one or more properties of an instance of
IContext
have changed. Specific details are described in
the ContextEvent
.
-
-
Specified by:
-
contextChanged
in interface
IContextListener
-
-
Parameters:
-
contextEvent
- the context event. Guaranteed not to be null
.
getActiveContextIds
public final
Set getActiveContextIds()
- Returns the set of active context identifiers.
-
-
-
Returns:
- The set of active context identifiers; this value may be
null
if no active contexts have been set yet. If
the set is not null
, then it contains only
instances of String
.
getContext
public final
Context getContext(
String contextId)
- Gets the context with the given identifier. If no such context currently
exists, then the context will be created (but be undefined).
-
-
-
Parameters:
-
contextId
- The identifier to find; must not be null
.
-
Returns:
- The context with the given identifier; this value will never be
null
, but it might be undefined. -
See Also:
-
Context
getDefinedContextIds
public final
Set getDefinedContextIds()
- Returns the set of identifiers for those contexts that are defined.
-
-
-
Returns:
- The set of defined context identifiers; this value may be empty,
but it is never
null
.
getDefinedContexts
public final
Context[] getDefinedContexts()
- Returns the those contexts that are defined.
-
-
-
Returns:
- The defined contexts; this value may be empty, but it is never
null
. -
Since:
- 3.2
removeActiveContext
public final void removeActiveContext(
String contextId)
- Deactivates a context in this context manager.
-
-
-
Parameters:
-
contextId
- The identifier of the context to deactivate; must not be
null
.
removeContextManagerListener
public final void removeContextManagerListener(
IContextManagerListener listener)
- Removes a listener from this context manager.
-
-
-
Parameters:
-
listener
- The listener to be removed; must not be null
.
setActiveContextIds
public final void setActiveContextIds(
Set activeContextIds)
- Changes the set of active contexts for this context manager. The whole
set is required so that internal consistency can be maintained and so
that excessive recomputations do nothing occur.
-
-
-
Parameters:
-
activeContextIds
- The new set of active context identifiers; may be
null
.
Guidelines for using Eclipse APIs.
Copyright (c) Eclipse contributors and others 2000, 2008. All rights reserved.