fix for opening a file that does not belong to a library

editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/handlers/OpenFileHandler.java

 /*
  * Copyright (c) 2011, the Dart project authors.
  * 
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  * 
  * http://www.eclipse.org/legal/epl-v10.html
  * 
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
  * or implied. See the License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.dart.tools.ui.internal.handlers;
 
 import com.google.dart.tools.core.DartCore;
 import com.google.dart.tools.core.internal.util.Extensions;
 import com.google.dart.tools.core.internal.util.ResourceUtil;
 import com.google.dart.tools.core.model.DartLibrary;
 import com.google.dart.tools.core.model.DartModelException;
 import com.google.dart.tools.ui.DartToolsPlugin;
 import com.google.dart.tools.ui.DartUI;
-import com.google.dart.tools.ui.actions.ActionMessages;
+import com.google.dart.tools.ui.Messages;
 import com.google.dart.tools.ui.internal.actions.WorkbenchRunnableAdapter;
 import com.google.dart.tools.ui.internal.text.editor.EditorUtility;
 import com.google.dart.tools.ui.internal.util.ExceptionHandler;
 
 import org.eclipse.core.commands.AbstractHandler;
 import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IWorkspaceRunnable;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.jface.dialogs.IDialogSettings;
+import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.widgets.FileDialog;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.handlers.HandlerUtil;
 
 import java.io.File;
 import java.lang.reflect.InvocationTargetException;
 
@@ skipping 43 matching lines @@
                   if (file.getProject().equals(libFile[0].getDartProject().getProject())) {
                     files[0] = file;
                   }
                 }
               }
               monitor.done();
             }
           })); // workspace lock
 
     } catch (InvocationTargetException e) {
-      ExceptionHandler.handle(e, shell, ActionMessages.FormatAllAction_error_title,
-          ActionMessages.FormatAllAction_error_message);
+      ExceptionHandler.handle(e, shell, HandlerMessages.OpenFile_label,
+          HandlerMessages.OpenFile_errorMessage);
     } catch (InterruptedException e) {
       // canceled by user
     }
 
     try {
       if (files[0] != null) {
         EditorUtility.openInEditor(files[0], true);
+      } else if (libFile[0] == null) {
+        MessageDialog.openError(shell, HandlerMessages.OpenFile_label,
+            Messages.format(HandlerMessages.OpenFile_errorFileNotInLibrary, selectedFile.getName()));
       }
     } catch (PartInitException e) {
       throwFailedToOpen(selectedFile, e);
     } catch (DartModelException e) {
       throwFailedToOpen(selectedFile, e);
     }
     return null;
   }
 
   /**
@@ skipping 45 matching lines @@
     if (result != null) {
       settings.put(FILTER_PATH_KEY, dialog.getFilterPath());
     }
     return result;
   }
 
   private void throwFailedToOpen(File file, Exception e) throws ExecutionException {
     throw new ExecutionException("Failed to open " + file, e);
   }
 }