ElementValidator


1   /*******************************************************************************
2    * Copyright (c) 2000, 2006 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   *******************************************************************************/
11  package org.eclipse.jdt.internal.ui.util;
12  
13  import java.util.HashSet  ;
14  import java.util.Set  ;
15  
16  import org.eclipse.core.runtime.IAdaptable;
17  import org.eclipse.core.runtime.IStatus;
18  
19  import org.eclipse.core.resources.IResource;
20  
21  import org.eclipse.swt.widgets.Shell;
22  
23  import org.eclipse.jface.dialogs.ErrorDialog;
24  
25  import org.eclipse.jdt.core.ICompilationUnit;
26  import org.eclipse.jdt.core.IJavaElement;
27  
28  import org.eclipse.jdt.internal.corext.util.Resources;
29  
30  import org.eclipse.jdt.internal.ui.JavaUIMessages;
31  
32  /**
33   * Helper class to check if a set of <tt>IJavaElement</tt> objects can be
34   * modified by an operation.
35   * 
36   * @since   2.1
37   */
38  public class ElementValidator {
39  
40      private ElementValidator() {
41          // no instance
42      }
43  
44      /**
45       * Checks if the given element is in sync with the underlying file system.
46       * 
47       * @param element the element to be checked
48       * @param parent a parent shell used to present a dialog to the user if the
49       * element is not in sync
50       * @param title a dialog's title used to present a dialog to the user if the
51       * element is not in sync
52       * @return boolean <code>true</code> if the element is in sync with the file
53       * system. Otherwise <code>false</code> is returned
54       */
55      public static boolean checkInSync(IAdaptable element, Shell parent,String   title) {
56          return checkInSync(new IAdaptable[] {element}, parent, title);
57      }
58      
59      /**
60       * Checks if the given array of elements is in sync with the underlying file
61       * system.
62       * 
63       * @param elements the array of elements to be checked
64       * @param parent a parent shell used to present a dialog to the user if
65       * one of the elements is not in sync
66       * @param title a dialog's title used to present a dialog to the user if
67       * one of the elements is not in sync
68       * @return boolean <code>true</code> if the all elements are in sync with
69       * the file system. Otherwise <code>false</code> is returned
70       */
71      public static boolean checkInSync(IAdaptable[] elements, Shell parent, String   title) {
72          return checkInSync(getResources(elements), parent, title);
73      }
74      
75      /**
76       * Checks if the given element is read-only and if so the methods tries
77       * to make the element writable by calling validate edit. If
78       * <code>validateEdit</code> was able to make the file writable the method
79       * additionally checks if the file has been changed by calling
80       * <code>validateEdit</code>.
81       * 
82       * @param element the element to be checked
83       * @param parent a parent shell used to present a dialog to the user if the
84       * check fails
85       * @param title a dialog's title used to present a dialog to the user if the
86       * check fails
87       * @return boolean <code>true</code> if the element is writable and its
88       * content didn't change by calling <code>validateEdit</code>. Otherwise
89       * <code>false</code> is returned
90       * 
91       * @see org.eclipse.core.resources.IWorkspace#validateEdit(org.eclipse.core.resources.IFile[], java.lang.Object)
92       */
93      public static boolean checkValidateEdit(IJavaElement element, Shell parent, String   title) {
94          return checkValidateEdit(new IJavaElement[] {element}, parent, title);
95      }
96      
97      /**
98       * Checks if the given elements are read-only and if so the methods tries to
99       * make the element writable by calling <code>validateEdit</code>. If
100      * <code>validateEdit</code> was able to make the file writable the method
101      * additionally checks if the file has been changed by calling
102      * <code>validateEdit</code>.
103      * 
104      * @param elements the elements to be checked
105      * @param parent a parent shell used to present a dialog to the user if the
106      * check fails
107      * @param title a dialog's title used to present a dialog to the user if the
108      * check fails
109      * @return boolean <code>true</code> if all elements are writable and their
110      * content didn't change by calling <code>validateEdit</code>. Otherwise
111      * <code>false</code> is returned
112      * 
113      * @see org.eclipse.core.resources.IWorkspace#validateEdit(org.eclipse.core.resources.IFile[], java.lang.Object)
114      */
115     public static boolean checkValidateEdit(IJavaElement[] elements, Shell parent, String   title) {
116         return checkValidateEdit(getResources(elements), parent, title);
117     }
118     
119     /**
120      * Checks a combination of <code>checkInSync</code> and
121      * <code>checkValidateEdit</code> depending of the value of
122      * <code>editor</code>. If <code>editor</code> is <code>true</code> only
123      * <code>checkValidateEdit</code> is performed since the editor does a in
124      * sync check on focus change. If <code>editor</code> is <code>false</code>
125      * both checks are performed.
126      * 
127      * @param element the element to be checked
128      * @param parent a parent shell used to present a dialog to the user if the
129      * check fails
130      * @param title a dialog's title used to present a dialog to the user if the
131      * check fails
132      * @return boolean <code>true</code> if the element passed the checks.
133      * Otherwise <code>false</code> is returned
134      * 
135      * @see #checkInSync(IAdaptable, Shell, String)
136      * @see #checkValidateEdit(IJavaElement, Shell, String)
137      */
138     public static boolean check(IJavaElement element, Shell parent, String   title, boolean editor) {
139         return check(new IJavaElement[] {element}, parent, title, editor);
140     }
141     
142     /**
143      * Checks a combination of <code>checkInSync</code> and
144      * <code>checkValidateEdit</code> depending of the value of
145      * <code>editor</code>. If <code>editor</code> is <code>true</code> only
146      * <code>checkValidateEdit</code> is performed since the editor does a in
147      * sync check on focus change. If <code>editor</code> is <code>false</code>
148      * both checks are performed.
149      * 
150      * @param elements the elements to be checked
151      * @param parent a parent shell used to present a dialog to the user if the
152      * check fails
153      * @param title a dialog's title used to present a dialog to the user if the
154      * check fails
155      * @return boolean <code>true</code> if all elements pass the checks.
156      * Otherwise <code>false</code> is returned
157      * 
158      * @see #checkInSync(IAdaptable[], Shell, String)
159      * @see #checkValidateEdit(IJavaElement[], Shell, String)
160      */
161     public static boolean check(IJavaElement[] elements, Shell parent,String   title, boolean editor) {
162         IResource[] resources= getResources(elements);
163         if (!editor && !checkInSync(resources, parent, title))
164             return false;
165         return checkValidateEdit(resources, parent, title);
166     }
167 
168     private static boolean checkInSync(IResource[] resources, Shell parent, String   title) {
169         IStatus status= Resources.checkInSync(resources);
170         if (status.isOK())
171             return true;
172         ErrorDialog.openError(parent, title, 
173             JavaUIMessages.ElementValidator_cannotPerform, 
174             status);
175         return false;
176     }
177 
178     private static boolean checkValidateEdit(IResource[] resources, Shell parent, String   title) {
179         IStatus status= Resources.makeCommittable(resources, parent);
180         if (!status.isOK()) {
181             ErrorDialog.openError(parent, title, 
182                 JavaUIMessages.ElementValidator_cannotPerform, 
183                 status);
184             return false;           
185         }
186         return true;
187     }
188     
189     private static IResource[] getResources(IAdaptable[] elements) {
190         Set   result= new HashSet  ();
191         for (int i= 0; i < elements.length; i++) {
192             IAdaptable element= elements[i];
193             IResource resource= null;
194             if (element instanceof IJavaElement) {
195                 IJavaElement je= (IJavaElement)element;
196                 ICompilationUnit cu= (ICompilationUnit)je.getAncestor(IJavaElement.COMPILATION_UNIT);
197                 if (cu != null) {
198                     je= cu.getPrimary();
199                 }
200                 resource= je.getResource();
201             } else {
202                 resource= (IResource)element.getAdapter(IResource.class);
203             }
204             if (resource != null)
205                 result.add(resource);
206         }
207         return (IResource[]) result.toArray(new IResource[result.size()]);
208     }   
209 }
210
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