添加到emf模型

Question

我有一个基于emf的模型。在模型中，我有一个feature类，我可以向这些feature添加约束。例如，特性A“暗示”特性B。我正在尝试使用emf命令堆栈向特性添加约束。它将约束添加到特征中，但缺少属性。我的代码如下

 public static Object doExecute(Feature contextFeature, FeatureModel featureModel, ComposedAdapterFactory adapterFactory) {


    CreateConstraintDialog dlg = new CreateConstraintDialog(Display.getCurrent().getActiveShell(), contextFeature, featureModel, adapterFactory);
    dlg.open();

    // check if dialog was cancelled:
    if (dlg.getReturnCode() == Window.CANCEL)
        return null;

    Feature selectedFeature = dlg.getSelectedFeature();
    if (selectedFeature == null)
        return null;

    ConstraintType selectedConstraintType = dlg.getSelectedConstraintType();

    Constraint constraint = FmFactory.eINSTANCE.createConstraint();
    constraint.setType(selectedConstraintType);
    constraint.setConstrainedFeature(selectedFeature);
    constraint.setContext(contextFeature);

    EditingDomain editingDomain = AdapterFactoryEditingDomain.getEditingDomainFor(contextFeature);
    Command cmd = AddCommand.create(editingDomain, contextFeature, FmPackage.FEATURE__CONSTRAINTS, constraint);
    editingDomain.getCommandStack().execute(cmd);
    return null;

}

/**
 * <!-- begin-user-doc -->
 * <!-- end-user-doc -->
 * @generated
 */
public void setContext(Feature newContext) {
    if (newContext != eInternalContainer() || (eContainerFeatureID() != FmPackage.CONSTRAINT__CONTEXT && newContext != null)) {
        if (EcoreUtil.isAncestor(this, newContext))
            throw new IllegalArgumentException("Recursive containment not allowed for " + toString());
        NotificationChain msgs = null;
        if (eInternalContainer() != null)
            msgs = eBasicRemoveFromContainer(msgs);
        if (newContext != null)
            msgs = ((InternalEObject)newContext).eInverseAdd(this, FmPackage.FEATURE__CONSTRAINTS, Feature.class, msgs);
        msgs = basicSetContext(newContext, msgs);
        if (msgs != null) msgs.dispatch();
    }
    else if (eNotificationRequired())
        eNotify(new ENotificationImpl(this, Notification.SET, FmPackage.CONSTRAINT__CONTEXT, newContext, newContext));
}

Answer 1

由于您刚刚创建了constraint实例，因此不需要使用命令来设置它的属性，因为它还没有附加到EMF模型。您可以只调用setter方法。使用命令的地方只是将constraint添加到现有特性中。

不相关，但在执行命令之前，您还应该始终对该命令调用canexecute方法：

CompoundCommand cmd = ....;
if (cmd.canExecute()) {
    editingDomain.getCommandStack().execute( cmd );
}