org.eclipse.emf.emfstore.internal.client.ui.handlers

Class AbstractEMFStoreHandlerWithResult<T>

java.lang.Object

org.eclipse.core.commands.common.EventManager

org.eclipse.core.commands.AbstractHandler

org.eclipse.emf.emfstore.internal.client.ui.handlers.AbstractEMFStoreHandlerWithResult<T>

Type Parameters:

T - the return type of the handler

All Implemented Interfaces:

org.eclipse.core.commands.IHandler, org.eclipse.core.commands.IHandler2

Direct Known Subclasses:

AbstractEMFStoreHandler

public abstract class AbstractEMFStoreHandlerWithResult<T>
extends org.eclipse.core.commands.AbstractHandler

Handlers are the top level abstraction that clients should use execute actions within the EMFStore workspace. They are responsible for calling the UI controllers and therefore provide helper methods that can determine the currently selected element, if needed. This handler is capable of returning a result.

Author:

ovonwesen, emueller

See Also:

AbstractEMFStoreHandler

Constructor Summary

Constructors

Constructor and Description
AbstractEMFStoreHandlerWithResult()

Method Summary

Modifier and Type	Method and Description
T	execute(org.eclipse.core.commands.ExecutionEvent event)
org.eclipse.swt.widgets.Shell	getShell() Returns the currently active shell.
abstract T	handleWithResult() Executes the handler and returns a result.
<U> boolean	hasSelection(Class<U> clazz) Returns whether an object of the given clazz can be extracted from the current selection.
<U> U	requireSelection(Class<U> clazz) Returns an object of the given clazz if it can be extracted from the current selection.

Methods inherited from class org.eclipse.core.commands.AbstractHandler

addHandlerListener, dispose, isEnabled, isHandled, removeHandlerListener, setEnabled

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractEMFStoreHandlerWithResult

public AbstractEMFStoreHandlerWithResult()

Method Detail

execute

public T execute(org.eclipse.core.commands.ExecutionEvent event)
          throws org.eclipse.core.commands.ExecutionException

Throws:

org.eclipse.core.commands.ExecutionException

See Also:

IHandler.execute(org.eclipse.core.commands.ExecutionEvent)

handleWithResult

public abstract T handleWithResult()

Executes the handler and returns a result.

Returns:

a return value of type T

requireSelection

public <U> U requireSelection(Class<U> clazz)
                       throws RequiredSelectionException

Returns an object of the given clazz if it can be extracted from the current selection.

Type Parameters:

U - the type of the object to be extracted from the current selection

Parameters:

clazz - the type of the object that is requested to be extracted from the current selection

Returns:

an object of type T that is contained within the current selection

Throws:

RequiredSelectionException - if the selection is invalid, i.e. if no object of the given type is contained in the selection or if the selection is null

hasSelection

public <U> boolean hasSelection(Class<U> clazz)

Returns whether an object of the given clazz can be extracted from the current selection.

Type Parameters:

U - the type of the object to be extracted from the current selection

Parameters:

clazz - the type of the object that is requested to be extracted from the current selection

Returns:

true, if an object of type T is contained within the current selection, false otherwise

getShell

public org.eclipse.swt.widgets.Shell getShell()

Returns the currently active shell.

Returns:

the active shell