Package org.eclipse.e4.core.contexts

Class ContextFunction

java.lang.Object

org.eclipse.e4.core.contexts.ContextFunction

All Implemented Interfaces:

IContextFunction

Direct Known Subclasses:

BindingServiceCreationFunction, CommandServiceCreationFunction, EventBrokerFactory, HandlerServiceCreationFunction, LocaleChangeServiceContextFunction

public abstract class ContextFunction
extends Object
implements IContextFunction

The base class for all computed value implementations. Clients may subclass this class. See the class comment of IContextFunction for specific rules that must be followed by function implementations.

This class is intended to be subclassed by clients.

Since:

1.3

See Also:

• IContextFunction

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.e4.core.contexts.IContextFunction

IContextFunction.ServiceContextKey

Field Summary

Fields inherited from interface org.eclipse.e4.core.contexts.IContextFunction

SERVICE_CONTEXT_KEY, SERVICE_NAME

Constructor Summary

Constructors

Constructor	Description
ContextFunction()	Constructs a new instance of the context function

Method Summary

Modifier and Type	Method	Description
Object	compute(IEclipseContext context)	Deprecated. IContextFunction's compute() was changed to take the context key
Object	compute(IEclipseContext context, String contextKey)	Evaluates the function based on the provided arguments and context to produce a consistent result.

Methods inherited from class java.lang.Object

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

Constructor Details

ContextFunction

public ContextFunction()

Constructs a new instance of the context function

Method Details

compute

@Deprecated
public Object compute(IEclipseContext context)

Deprecated.

IContextFunction's compute() was changed to take the context key

compute

public Object compute(IEclipseContext context,
 String contextKey)

Description copied from interface: IContextFunction

Evaluates the function based on the provided arguments and context to produce a consistent result.

Specified by:

compute in interface IContextFunction

Parameters:

context - The context in which to perform the value computation.

contextKey - The context key used to find this function; may be null such as if invoked directly.

Returns:

The concrete value. Implementations may return IInjector.NOT_A_VALUE to cause lookup to continue up the context hierarchy.