core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/ui/wizards/WorkingSetDetector.java

/*******************************************************************************
 * Copyright (c) 2009, 2018 xored software, Inc. 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
 *
 * Contributors:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.ui.wizards;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.dltk.internal.ui.scriptview.ScriptExplorerPart;
import org.eclipse.dltk.internal.ui.workingsets.WorkingSetIDs;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeSelection;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.IWorkingSet;

/**
 * Detects {@link IWorkingSet}s selected before project wizard was called.
 *
 * @since 2.0
 */
public class WorkingSetDetector {

	private static final IWorkingSet[] EMPTY_WORKING_SET_ARRAY = new IWorkingSet[0];

	/**
	 * Detects workings sets currently selected
	 *
	 * @param selection
	 * @param workbench
	 * @return
	 */
	public IWorkingSet[] detect(IStructuredSelection selection,
			IWorkbench workbench) {
		IWorkingSet[] selected = getSelectedWorkingSet(selection);
		if (selected != null && selected.length > 0) {
			for (int i = 0; i < selected.length; i++) {
				if (!isValidWorkingSet(selected[i]))
					return EMPTY_WORKING_SET_ARRAY;
			}
			return selected;
		}

		IWorkbenchPart activePart = getActivePart(workbench);

		if (!(activePart instanceof ScriptExplorerPart))
			return EMPTY_WORKING_SET_ARRAY;

		ScriptExplorerPart explorerPart = (ScriptExplorerPart) activePart;
		if (explorerPart
				.getRootMode() == ScriptExplorerPart.PROJECTS_AS_ROOTS) {
			// Get active filter
			IWorkingSet filterWorkingSet = explorerPart.getFilterWorkingSet();
			if (filterWorkingSet == null)
				return EMPTY_WORKING_SET_ARRAY;

			if (!isValidWorkingSet(filterWorkingSet))
				return EMPTY_WORKING_SET_ARRAY;

			return new IWorkingSet[] { filterWorkingSet };
		}
		// If we have been gone into a working set return the working set
		Object input = explorerPart.getViewPartInput();
		if (!(input instanceof IWorkingSet))
			return EMPTY_WORKING_SET_ARRAY;

		IWorkingSet workingSet = (IWorkingSet) input;
		if (!isValidWorkingSet(workingSet))
			return EMPTY_WORKING_SET_ARRAY;

		return new IWorkingSet[] { workingSet };
	}

	private IWorkbenchPart getActivePart(IWorkbench workbench) {
		IWorkbenchWindow activeWindow = workbench.getActiveWorkbenchWindow();
		if (activeWindow != null) {
			IWorkbenchPage activePage = activeWindow.getActivePage();
			if (activePage != null) {
				return activePage.getActivePart();
			}
		}
		return null;
	}

	private IWorkingSet[] getSelectedWorkingSet(
			IStructuredSelection selection) {
		if (!(selection instanceof ITreeSelection))
			return EMPTY_WORKING_SET_ARRAY;

		ITreeSelection treeSelection = (ITreeSelection) selection;
		if (treeSelection.isEmpty())
			return EMPTY_WORKING_SET_ARRAY;

		List<?> elements = treeSelection.toList();
		if (elements.size() == 1) {
			Object element = elements.get(0);
			TreePath[] paths = treeSelection.getPathsFor(element);
			if (paths.length != 1)
				return EMPTY_WORKING_SET_ARRAY;

			TreePath path = paths[0];
			if (path.getSegmentCount() == 0)
				return EMPTY_WORKING_SET_ARRAY;

			Object candidate = path.getSegment(0);
			if (!(candidate instanceof IWorkingSet))
				return EMPTY_WORKING_SET_ARRAY;

			IWorkingSet workingSetCandidate = (IWorkingSet) candidate;
			if (isValidWorkingSet(workingSetCandidate))
				return new IWorkingSet[] { workingSetCandidate };

			return EMPTY_WORKING_SET_ARRAY;
		}

		List<IWorkingSet> result = new ArrayList<>();
		for (Iterator<?> iterator = elements.iterator(); iterator.hasNext();) {
			Object element = iterator.next();
			if (element instanceof IWorkingSet) {
				final IWorkingSet ws = (IWorkingSet) element;
				if (isValidWorkingSet(ws)) {
					result.add(ws);
				}
			}
		}
		return result.toArray(new IWorkingSet[result.size()]);
	}

	protected boolean isValidWorkingSet(IWorkingSet workingSet) {
		String id = workingSet.getId();
		if (!WorkingSetIDs.SCRIPT.equals(id)
				&& !WorkingSetIDs.RESOURCE.equals(id))
			return false;

		if (workingSet.isAggregateWorkingSet())
			return false;

		return true;
	}

}