import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public ViewInstanceDescriptor ( final String id, final String parentId, final ViewInstanceFactory factory, final URI uri, final String name, final int order, final boolean defaultInstance, final Boolean zooming, final Expression lazyExpression, final Expression visibleExpression, final Expression defaultInstanceExpression, final String summaryConnectionId, final String summaryItemId, final boolean mainView, final Map<String, String> properties )
{
    super ();
    this.id = id;
    this.parentId = parentId;
    this.factory = factory;
    this.uri = uri;
    this.name = name;
    this.properties = properties;
    this.order = order;
    this.defaultInstance = defaultInstance;
    this.zooming = zooming;
    this.lazyExpression = lazyExpression;
    this.visibleExpression = visibleExpression;
    this.defaultInstanceExpression = defaultInstanceExpression;
    this.summaryConnectionId = summaryConnectionId;
    this.summaryItemId = summaryItemId;
    this.mainView = mainView;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
private ModernActionKeyBindingSupport(
    final IAdaptable serviceLocator,
    final Expression expression,
    final int sourcePriorities) {
    Check.notNull(serviceLocator, "serviceLocator"); //$NON-NLS-1$
    Check.notNull(expression, "expression"); //$NON-NLS-1$

    bindingService = (IBindingService) serviceLocator.getAdapter(IBindingService.class);
    handlerService = (IHandlerService) serviceLocator.getAdapter(IHandlerService.class);

    if (bindingService == null || handlerService == null) {
        throw new IllegalArgumentException(
            "specified IAdapable could not provide IBindingService or IHandlerService"); //$NON-NLS-1$
    }

    this.expression = expression;
    this.sourcePriorities = sourcePriorities;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public boolean test(Object receiver, String property, Object[] args,
    Object expectedValue) {
  String delegateShortcutID = (String) args[0];
  Expression expr = expressions.get(delegateShortcutID);
  if (expr == null) {
    expr = createEnablementExpression(delegateShortcutID);
    expressions.put(delegateShortcutID, expr);
  }
  try {
    return expr.evaluate(createContext(receiver)) != EvaluationResult.FALSE;
  } catch (CoreException ce) {
    EclEmmaUIPlugin.getInstance().getLog()
        .log(EclEmmaUIPlugin.errorStatus("Launch shortcut '" //$NON-NLS-1$
            + delegateShortcutID
            + "' enablement expression caused exception.", //$NON-NLS-1$
            ce));
    return false;
  }
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
@Override
public void createContributionItems(IServiceLocator serviceLocator, IContributionRoot additions) {
	IMenuService menuService = (IMenuService) serviceLocator.getService(IMenuService.class);
	if (menuService == null) {
		CloudFoundryPlugin
				.logError("Unable to retrieve Eclipse menu service. Cannot add Cloud Foundry context menus."); //$NON-NLS-1$
		return;
	}

	List<IAction> debugActions = getActions(menuService);
	for (IAction action : debugActions) {
		additions.addContributionItem(new ActionContributionItem(action), new Expression() {
			public EvaluationResult evaluate(IEvaluationContext context) {
				return EvaluationResult.TRUE;
			}

			public void collectExpressionInfo(ExpressionInfo info) {
			}
		});
	}
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
@Override
public void createContributionItems(IServiceLocator serviceLocator, IContributionRoot additions) {
	IMenuService menuService = (IMenuService) serviceLocator.getService(IMenuService.class);
	if (menuService == null) {
		DockerFoundryPlugin
				.logError("Unable to retrieve Eclipse menu service. Cannot add Cloud Foundry context menus."); //$NON-NLS-1$
		return;
	}

	List<IAction> debugActions = getActions(menuService);
	for (IAction action : debugActions) {
		additions.addContributionItem(new ActionContributionItem(action), new Expression() {
			public EvaluationResult evaluate(IEvaluationContext context) {
				return EvaluationResult.TRUE;
			}

			public void collectExpressionInfo(ExpressionInfo info) {
			}
		});
	}
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
@Override
public void createContributionItems(IServiceLocator serviceLocator,
		IContributionRoot additions) {
	CommandContributionItemParameter toggleWatchpointParam = new CommandContributionItemParameter(serviceLocator, null, "org.eclipse.debug.ui.commands.ToggleWatchpoint", CommandContributionItem.STYLE_PUSH);
	toggleWatchpointParam.icon = DebugUITools.getImageDescriptor(IDebugUIConstants.IMG_OBJS_WATCHPOINT);
	toggleWatchpointParam.disabledIcon = DebugUITools.getImageDescriptor(IDebugUIConstants.IMG_OBJS_WATCHPOINT_DISABLED);
	toggleWatchpointParam.label = "Add Watchpoint";
	CommandContributionItem toggleWatchpoint = new CommandContributionItem(toggleWatchpointParam);
	Expression toggleWatchpointVisible = new Expression() {
		
		@Override
		public EvaluationResult evaluate(IEvaluationContext context)
				throws CoreException {
			return EvaluationResult.valueOf((context.getVariable("activeEditor") instanceof BfEditor));
		}
	};
	additions.addContributionItem(toggleWatchpoint, toggleWatchpointVisible);
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
@Override
public void createContributionItems(IServiceLocator serviceLocator, IContributionRoot additions) {
	for (PlanModifierFactory factory : PlanModifierRegistry.getInstance().getModifierFactories()) {
		String name = factory.getName();
		ImageDescriptor imageDescriptor = factory.getImageDescriptor();
		String id = null;
		String commandId = TEMPORAL_MODIFICATION_COMMAND_ID;
		Map<?, ?> parameters = Collections.singletonMap("name", name);
		ImageDescriptor icon = imageDescriptor;
		String label = name;
		String tooltip = name;
		FactoryServiceLocator locator = new FactoryServiceLocator(serviceLocator, factory);
		CommandContributionItemParameter parameter = new CommandContributionItemParameter(locator, id, commandId, parameters, icon, null, null, label, null, tooltip, SWT.RADIO, null, false);
		IContributionItem item = new CommandContributionItem(parameter);
		Expression visibleWhen = null;
		additions.addContributionItem(item, visibleWhen);
	}
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public boolean matches(IJavaProject javaProject) {
	if (fStatus != null) {
		return fStatus.booleanValue();
	}

	IConfigurationElement[] children= fConfigurationElement.getChildren(ExpressionTagNames.ENABLEMENT);
	if (children.length == 1) {
		try {
			ExpressionConverter parser= ExpressionConverter.getDefault();
			Expression expression= parser.perform(children[0]);
			EvaluationContext evalContext= new EvaluationContext(null, javaProject);
			evalContext.addVariable("project", javaProject); //$NON-NLS-1$
			evalContext.addVariable("sourceLevel", javaProject.getOption(JavaCore.COMPILER_SOURCE, true)); //$NON-NLS-1$
			return expression.evaluate(evalContext) == EvaluationResult.TRUE;
		} catch (CoreException e) {
			JavaPlugin.log(e);
		}
		return false;
	}
	fStatus= Boolean.FALSE;
	return false;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public static EditPart createEditPart( EditPart context, Object model )
{
	EvaluationContext econtext = new EvaluationContext( null, model );
	for ( Iterator<Expression> iterator = extensionMap.keySet( ).iterator( ); iterator.hasNext( ); )
	{
		try
		{
			Expression expression = iterator.next( );
			if ( expression.evaluate( econtext ) == EvaluationResult.TRUE )
			{
				EditPart editPart = (EditPart) extensionMap.get( expression )
						.createExecutableExtension( "type" ); //$NON-NLS-1$
				editPart.setModel( model );
				return editPart;
			}
		}
		catch ( CoreException e )
		{
			logger.log( Level.SEVERE, e.getMessage( ), e );
		}
	}
	return null;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
private Expression createEnablementExpression(String delegateShortcutID) {
  IConfigurationElement element = findEnablementConfiguration(delegateShortcutID);
  if (element != null) {
    try {
      return ExpressionConverter.getDefault().perform(element);
    } catch (CoreException ce) {
      EclEmmaUIPlugin.log(ce);
    }
  }
  return Expression.FALSE;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
private boolean matches(ICompilationUnit cunit) {
	if (fRequiredSourceLevel != null) {
		String current= cunit.getJavaProject().getOption(JavaCore.COMPILER_SOURCE, true);
		if (JavaModelUtil.isVersionLessThan(current, fRequiredSourceLevel)) {
			return false;
		}
	}

	if (fStatus != null) {
		return fStatus.booleanValue();
	}

	IConfigurationElement[] children= fConfigurationElement.getChildren(ExpressionTagNames.ENABLEMENT);
	if (children.length == 1) {
		try {
			ExpressionConverter parser= ExpressionConverter.getDefault();
			Expression expression= parser.perform(children[0]);
			EvaluationContext evalContext= new EvaluationContext(null, cunit);
			evalContext.addVariable("compilationUnit", cunit); //$NON-NLS-1$
			IJavaProject javaProject= cunit.getJavaProject();
			String[] natures= javaProject.getProject().getDescription().getNatureIds();
			evalContext.addVariable("projectNatures", Arrays.asList(natures)); //$NON-NLS-1$
			evalContext.addVariable("sourceLevel", javaProject.getOption(JavaCore.COMPILER_SOURCE, true)); //$NON-NLS-1$
			return expression.evaluate(evalContext) == EvaluationResult.TRUE;
		} catch (CoreException e) {
			JavaPlugin.log(e);
		}
		return false;
	}
	fStatus= Boolean.FALSE;
	return false;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public Expression getDefaultInstanceExpression ()
{
    return this.defaultInstanceExpression;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public Expression getLazyExpression ()
{
    return this.lazyExpression;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public Expression getVisibleExpression ()
{
    return this.visibleExpression;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public Expression getExpression( )
{
	return expression;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
public void setExpression( Expression expression )
{
	this.expression = expression;
}
 

import org.eclipse.core.expressions.Expression; //导入依赖的package包/类
/**
 * Returns the enablement element of the described extension.
 * 
 * @return the enablement expression or <code>null</code> if it is not specified
 * @since 3.8.1
 */
Expression getEnablementExpression() {
	return fEnablementExpression;
}