core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/internal/ui/typehierarchy/FocusOnSelectionAction.java

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 *******************************************************************************/
package org.eclipse.dltk.internal.ui.typehierarchy;

import org.eclipse.dltk.core.IType;
import org.eclipse.dltk.internal.corext.util.Messages;
import org.eclipse.dltk.internal.ui.util.SelectionUtil;
import org.eclipse.dltk.ui.ScriptElementLabels;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionProvider;

/**
 * Refocuses the type hierarchy on the currently selection type.
 */
public class FocusOnSelectionAction extends Action {

	private TypeHierarchyViewPart fViewPart;

	public FocusOnSelectionAction(TypeHierarchyViewPart part) {
		super(TypeHierarchyMessages.FocusOnSelectionAction_label);
		setDescription(TypeHierarchyMessages.FocusOnSelectionAction_description);
		setToolTipText(TypeHierarchyMessages.FocusOnSelectionAction_tooltip);
		fViewPart= part;

		//PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IJavaHelpContextIds.FOCUS_ON_SELECTION_ACTION);
	}

	private ISelection getSelection() {
		ISelectionProvider provider= fViewPart.getSite().getSelectionProvider();
		if (provider != null) {
			return provider.getSelection();
		}
		return null;
	}

	@Override
	public void run() {
		Object element= SelectionUtil.getSingleElement(getSelection());
		if (element instanceof IType) {
			fViewPart.setInputElement((IType)element);
		}
	}

	public boolean canActionBeAdded() {
		Object element= SelectionUtil.getSingleElement(getSelection());
		if (element instanceof IType) {
			IType type= (IType)element;
			setText(Messages.format(
					TypeHierarchyMessages.FocusOnSelectionAction_label,
					ScriptElementLabels.getDefault().getTextLabel(type, 0)));
			return true;
		}
		return false;
	}
}