core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/internal/ui/wizards/buildpath/BPListElementSorter.java

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 *******************************************************************************/
package org.eclipse.dltk.internal.ui.wizards.buildpath;

import org.eclipse.dltk.core.IAccessRule;
import org.eclipse.dltk.core.IBuildpathEntry;
import org.eclipse.jface.viewers.ContentViewer;
import org.eclipse.jface.viewers.IBaseLabelProvider;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;

public class BPListElementSorter extends ViewerComparator {

	private static final int SOURCE = 0;
	private static final int PROJECT = 1;
	private static final int LIBRARY = 2;
	private static final int CONTAINER = 3;

	private static final int ATTRIBUTE = 5;
	private static final int CONTAINER_ENTRY = 6;

	private static final int OTHER = 7;

	@Override
	public int category(Object obj) {
		if (obj instanceof BPListElement) {
			BPListElement element = (BPListElement) obj;
			if (element.getParentContainer() != null) {
				return CONTAINER_ENTRY;
			}
			switch (element.getEntryKind()) {
			case IBuildpathEntry.BPE_LIBRARY:
				return LIBRARY;
			case IBuildpathEntry.BPE_PROJECT:
				return PROJECT;
			case IBuildpathEntry.BPE_SOURCE:
				return SOURCE;
			case IBuildpathEntry.BPE_CONTAINER:
				return CONTAINER;
			}
		} else if (obj instanceof BPListElementAttribute) {
			return ATTRIBUTE;
		} else if (obj instanceof IAccessRule) {
			return ATTRIBUTE;
		}
		return OTHER;
	}

	@Override
	public int compare(Viewer viewer, Object e1, Object e2) {

		int cat1 = category(e1);
		int cat2 = category(e2);

		if (cat1 != cat2)
			return cat1 - cat2;

		if (cat1 == ATTRIBUTE || cat1 == CONTAINER_ENTRY) {
			return 0; // do not sort attributes or container entries
		}

		if (viewer instanceof ContentViewer) {
			IBaseLabelProvider prov = ((ContentViewer) viewer)
					.getLabelProvider();
			if (prov instanceof ILabelProvider) {
				ILabelProvider lprov = (ILabelProvider) prov;
				String name1 = lprov.getText(e1);
				String name2 = lprov.getText(e2);
				return getComparator().compare(name1, name2);
			}
		}
		return 0;
	}

}