ant/org.eclipse.ant.ui/Ant Tools Support/org/eclipse/ant/internal/ui/preferences/AntContentProvider.java

/*******************************************************************************
 * Copyright (c) 2000, 2009 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
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ant.internal.ui.preferences;


import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;

/**
 * Content provider that maintains a generic list of objects which are shown in
 * a table viewer.
 */
public class AntContentProvider implements IStructuredContentProvider {
	protected List elements = new ArrayList();
	protected TableViewer tableViewer;
	private ViewerComparator fComparator= null;
	/**
	 * @since 3.5
	 */
	private boolean defaultcomparator = true;
	
	
	/**
	 * Default Constructor
	 */
	public AntContentProvider() {
	}
	
	/**
	 * Constructor
	 * 
	 * @param defaultcomparator if the default comparator should be used for the returned data
	 * @since 3.5
	 */
	public AntContentProvider(boolean defaultcomparator) {
		this.defaultcomparator = defaultcomparator;
	}
	
	/**
	 * Add an element to the current listing of elements and to the underlying viewer. Does nothing
	 * if the listing already contains the given element
	 * @param o
	 */
	public void add(Object o) {
		if (elements.contains(o)) {
			return;
		}
		elements.add(o);
		tableViewer.add(o);
		tableViewer.setSelection(new StructuredSelection(o), true);
	}

	/**
	 * @see org.eclipse.jface.viewers.IContentProvider#dispose()
	 */
	public void dispose() {
	}

	/**
	 * @see org.eclipse.jface.viewers.IStructuredContentProvider#getElements(java.lang.Object)
	 */
	public Object[] getElements(Object inputElement) {
		return elements.toArray();
	}

	/**
	 * @see org.eclipse.jface.viewers.IContentProvider#inputChanged(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
	 */
	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
		tableViewer = (TableViewer) viewer;
		elements.clear();
		if (newInput != null) {
			if(defaultcomparator) {
				tableViewer.setComparator(getComparator());
			}
			List list;
			if (newInput instanceof List) {
				list= (List) newInput;
			} else {
				list= Arrays.asList((Object[]) newInput);	
			}
			elements.addAll(list);
		}
	}

	/**
	 * Removes the given element from the listing of elements and from the backing viewer.
	 * @param o
	 */
	public void remove(Object o) {
		elements.remove(o);
		tableViewer.remove(o);
	}
	
	/**
	 * Removes the given selection of the listing of elements and from the backing viewer
	 * @param selection
	 */
	public void remove(IStructuredSelection selection) {
		Object[] array= selection.toArray();
		elements.removeAll(Arrays.asList(array));
		tableViewer.remove(array);
	}

	/**
	 * Returns the default comparator which compares the {@link #toString()} value of the elements for ordering
	 * @return the default comparator
	 */
	protected ViewerComparator getComparator() {
		if (fComparator == null) {
			fComparator= new ViewerComparator() {
				/* (non-Javadoc)
				 * @see org.eclipse.jface.viewers.ViewerComparator#compare(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
				 */
				public int compare(Viewer viewer, Object e1, Object e2) {
					return e1.toString().compareToIgnoreCase(e2.toString());
				}
			};
		}
		return fComparator;
	}
}