/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package net.sourceforge.phpdt.internal.ui.viewsupport;

import net.sourceforge.phpdt.core.IJavaElement;
import net.sourceforge.phpdt.internal.ui.PHPUIMessages;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IResource;
import org.eclipse.jface.action.IStatusLineManager;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;

/**
 * Add the <code>StatusBarUpdater</code> to your ViewPart to have the
 * statusbar describing the selected elements.
 */
public class StatusBarUpdater implements ISelectionChangedListener {

	private final int LABEL_FLAGS = JavaElementLabels.DEFAULT_QUALIFIED
			| JavaElementLabels.ROOT_POST_QUALIFIED
			| JavaElementLabels.APPEND_ROOT_PATH
			| JavaElementLabels.M_PARAMETER_TYPES
			| JavaElementLabels.M_PARAMETER_NAMES
			| JavaElementLabels.M_APP_RETURNTYPE
			| JavaElementLabels.M_EXCEPTIONS
			| JavaElementLabels.F_APP_TYPE_SIGNATURE;

	private IStatusLineManager fStatusLineManager;

	public StatusBarUpdater(IStatusLineManager statusLineManager) {
		fStatusLineManager = statusLineManager;
	}

	/*
	 * @see ISelectionChangedListener#selectionChanged
	 */
	public void selectionChanged(SelectionChangedEvent event) {
		String statusBarMessage = formatMessage(event.getSelection());
		fStatusLineManager.setMessage(statusBarMessage);
	}

	protected String formatMessage(ISelection sel) {
		if (sel instanceof IStructuredSelection && !sel.isEmpty()) {
			IStructuredSelection selection = (IStructuredSelection) sel;

			int nElements = selection.size();
			if (nElements > 1) {
				return PHPUIMessages
						.getFormattedString(
								"StatusBarUpdater.num_elements_selected", String.valueOf(nElements)); //$NON-NLS-1$
			} else {
				Object elem = selection.getFirstElement();
				if (elem instanceof IJavaElement) {
					return formatJavaElementMessage((IJavaElement) elem);
				} else if (elem instanceof IResource) {
					return formatResourceMessage((IResource) elem);
				}
			}
		}
		return ""; //$NON-NLS-1$
	}

	private String formatJavaElementMessage(IJavaElement element) {
		return JavaElementLabels.getElementLabel(element, LABEL_FLAGS);
	}

	private String formatResourceMessage(IResource element) {
		IContainer parent = element.getParent();
		if (parent != null && parent.getType() != IResource.ROOT)
			return element.getName() + JavaElementLabels.CONCAT_STRING
					+ parent.getFullPath().makeRelative().toString();
		else
			return element.getName();
	}

}