content: /*******************************************************************************
   * Copyright (c) 2000, 2008 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.wst.jsdt.internal.ui.util;
  
  import java.util.HashSet;
  import java.util.Set;
  
  import org.eclipse.core.resources.IResource;
  import org.eclipse.core.runtime.IAdaptable;
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.jface.dialogs.ErrorDialog;
  import org.eclipse.swt.widgets.Shell;
  import org.eclipse.wst.jsdt.core.IJavaScriptUnit;
  import org.eclipse.wst.jsdt.core.IJavaScriptElement;
  import org.eclipse.wst.jsdt.internal.corext.util.Resources;
  import org.eclipse.wst.jsdt.internal.ui.JavaUIMessages;
  
  /**
   * Helper class to check if a set of <tt>IJavaScriptElement</tt> objects can be
   * modified by an operation.
   * 
   * 
   */
  public class ElementValidator {
  
  	private ElementValidator() {
  		// no instance
  	}
  
  	/**
  	 * Checks if the given element is in sync with the underlying file system.
  	 * 
  	 * @param element the element to be checked
  	 * @param parent a parent shell used to present a dialog to the user if the
  	 * element is not in sync
  	 * @param title a dialog's title used to present a dialog to the user if the
  	 * element is not in sync
  	 * @return boolean <code>true</code> if the element is in sync with the file
  	 * system. Otherwise <code>false</code> is returned
  	 */
  	public static boolean checkInSync(IAdaptable element, Shell parent,String title) {
  		return checkInSync(new IAdaptable[] {element}, parent, title);
  	}
  	
  	/**
  	 * Checks if the given array of elements is in sync with the underlying file
  	 * system.
  	 * 
  	 * @param elements the array of elements to be checked
  	 * @param parent a parent shell used to present a dialog to the user if
  	 * one of the elements is not in sync
  	 * @param title a dialog's title used to present a dialog to the user if
  	 * one of the elements is not in sync
  	 * @return boolean <code>true</code> if the all elements are in sync with
  	 * the file system. Otherwise <code>false</code> is returned
  	 */
  	public static boolean checkInSync(IAdaptable[] elements, Shell parent, String title) {
  		return checkInSync(getResources(elements), parent, title);
  	}
  	
  	/**
  	 * Checks if the given element is read-only and if so the methods tries
  	 * to make the element writable by calling validate edit. If
  	 * <code>validateEdit</code> was able to make the file writable the method
  	 * additionally checks if the file has been changed by calling
  	 * <code>validateEdit</code>.
  	 * 
  	 * @param element the element to be checked
  	 * @param parent a parent shell used to present a dialog to the user if the
  	 * check fails
  	 * @param title a dialog's title used to present a dialog to the user if the
  	 * check fails
  	 * @return boolean <code>true</code> if the element is writable and its
  	 * content didn't change by calling <code>validateEdit</code>. Otherwise
  	 * <code>false</code> is returned
  	 * 
  	 * @see org.eclipse.core.resources.IWorkspace#validateEdit(org.eclipse.core.resources.IFile[], java.lang.Object)
  	 */
  	public static boolean checkValidateEdit(IJavaScriptElement element, Shell parent, String title) {
  		return checkValidateEdit(new IJavaScriptElement[] {element}, parent, title);
  	}
  	
  	/**
  	 * Checks if the given elements are read-only and if so the methods tries to
  	 * make the element writable by calling <code>validateEdit</code>. If
  	 * <code>validateEdit</code> was able to make the file writable the method
  	 * additionally checks if the file has been changed by calling
  	 * <code>validateEdit</code>.
  	 * 
  	 * @param elements the elements to be checked
  	 * @param parent a parent shell used to present a dialog to the user if the
  	 * check fails
  	 * @param title a dialog's title used to present a dialog to the user if the
  	 * check fails
  	 * @return boolean <code>true</code> if all elements are writable and their
  	 * content didn't change by calling <code>validateEdit</code>. Otherwise
  	 * <code>false</code> is returned
  	 * 
  	 * @see org.eclipse.core.resources.IWorkspace#validateEdit(org.eclipse.core.resources.IFile[], java.lang.Object)
  	 */
  	public static boolean checkValidateEdit(IJavaScriptElement[] elements, Shell parent, String title) {
  		return checkValidateEdit(getResources(elements), parent, title);
  	}
  	
  	/**
  	 * Checks a combination of <code>checkInSync</code> and
  	 * <code>checkValidateEdit</code> depending of the value of
  	 * <code>editor</code>. If <code>editor</code> is <code>true</code> only
  	 * <code>checkValidateEdit</code> is performed since the editor does a in
  	 * sync check on focus change. If <code>editor</code> is <code>false</code>
  	 * both checks are performed.
  	 * 
  	 * @param element the element to be checked
  	 * @param parent a parent shell used to present a dialog to the user if the
  	 * check fails
  	 * @param title a dialog's title used to present a dialog to the user if the
  	 * check fails
  	 * @return boolean <code>true</code> if the element passed the checks.
  	 * Otherwise <code>false</code> is returned
  	 * 
  	 * @see #checkInSync(IAdaptable, Shell, String)
  	 * @see #checkValidateEdit(IJavaScriptElement, Shell, String)
  	 */
  	public static boolean check(IJavaScriptElement element, Shell parent, String title, boolean editor) {
  		return check(new IJavaScriptElement[] {element}, parent, title, editor);
  	}
  	
  	/**
  	 * Checks a combination of <code>checkInSync</code> and
  	 * <code>checkValidateEdit</code> depending of the value of
  	 * <code>editor</code>. If <code>editor</code> is <code>true</code> only
  	 * <code>checkValidateEdit</code> is performed since the editor does a in
  	 * sync check on focus change. If <code>editor</code> is <code>false</code>
  	 * both checks are performed.
  	 * 
  	 * @param elements the elements to be checked
  	 * @param parent a parent shell used to present a dialog to the user if the
  	 * check fails
  	 * @param title a dialog's title used to present a dialog to the user if the
  	 * check fails
  	 * @return boolean <code>true</code> if all elements pass the checks.
  	 * Otherwise <code>false</code> is returned
  	 * 
  	 * @see #checkInSync(IAdaptable[], Shell, String)
  	 * @see #checkValidateEdit(IJavaScriptElement[], Shell, String)
  	 */
  	public static boolean check(IJavaScriptElement[] elements, Shell parent,String title, boolean editor) {
  		IResource[] resources= getResources(elements);
  		if (!editor && !checkInSync(resources, parent, title))
  			return false;
  		return checkValidateEdit(resources, parent, title);
  	}
  
  	private static boolean checkInSync(IResource[] resources, Shell parent, String title) {
  		IStatus status= Resources.checkInSync(resources);
  		if (status.isOK())
  			return true;
  		ErrorDialog.openError(parent, title, 
  			JavaUIMessages.ElementValidator_cannotPerform, 
  			status);
  		return false;
  	}
  
  	private static boolean checkValidateEdit(IResource[] resources, Shell parent, String title) {
  		IStatus status= Resources.makeCommittable(resources, parent);
  		if (!status.isOK()) {
  			ErrorDialog.openError(parent, title, 
  				JavaUIMessages.ElementValidator_cannotPerform, 
  				status);
  			return false;			
  		}
  		return true;
  	}
  	
  	private static IResource[] getResources(IAdaptable[] elements) {
  		Set result= new HashSet();
  		for (int i= 0; i < elements.length; i++) {
  			IAdaptable element= elements[i];
  			IResource resource= null;
  			if (element instanceof IJavaScriptElement) {
  				IJavaScriptElement je= (IJavaScriptElement)element;
  				IJavaScriptUnit cu= (IJavaScriptUnit)je.getAncestor(IJavaScriptElement.JAVASCRIPT_UNIT);
  				if (cu != null) {
  					je= cu.getPrimary();
  				}
  				resource= je.getResource();
  			} else {
  				resource= (IResource)element.getAdapter(IResource.class);
  			}
  			if (resource != null)
  				result.add(resource);
  		}
  		return (IResource[]) result.toArray(new IResource[result.size()]);
  	}	
  }
  