org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/uml2sd/load/LoadersManager.java

   1 /**********************************************************************
   2  * Copyright (c) 2005, 2008, 2011 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  * $Id: LoadersManager.java,v 1.5 2008/01/24 02:29:16 apnan Exp $
   8  *
   9  * Contributors:
  10  * IBM - Initial API and implementation
  11  * Bernd Hufmann - Updated for TMF
  12  **********************************************************************/
  13 package org.eclipse.linuxtools.tmf.ui.views.uml2sd.load;
  14
  15 import java.util.ArrayList;
  16 import java.util.HashMap;
  17 import java.util.Iterator;
  18 import java.util.List;
  19
  20 import org.eclipse.core.runtime.CoreException;
  21 import org.eclipse.core.runtime.IConfigurationElement;
  22 import org.eclipse.core.runtime.IExtension;
  23 import org.eclipse.core.runtime.IExtensionPoint;
  24 import org.eclipse.core.runtime.Platform;
  25 import org.eclipse.jface.preference.IPreferenceStore;
  26 import org.eclipse.linuxtools.internal.tmf.core.Tracer;
  27 import org.eclipse.linuxtools.internal.tmf.ui.TmfUiPlugin;
  28 import org.eclipse.linuxtools.tmf.ui.views.uml2sd.SDView;
  29 import org.eclipse.ui.IViewReference;
  30 import org.eclipse.ui.IWorkbenchPage;
  31
  32 /**
  33  * Manager class for the UML2SD extension point.
  34  */
  35 public class LoadersManager {
  36
  37     // ------------------------------------------------------------------------
  38     // Attributes
  39     // ------------------------------------------------------------------------
  40
  41     public static final String LOADER_TAG = "uml2SDLoader"; //$NON-NLS-1$
  42     public static final String LOADER_PREFIX = LOADER_TAG + "."; //$NON-NLS-1$
  43
  44     // The instance
  45     private static LoadersManager loadersManager;
  46
  47     // Maps for caching information
  48     protected HashMap<String, IUml2SDLoader> fViewLoaderMap = new HashMap<String, IUml2SDLoader>();
  49     protected HashMap<String, ArrayList<IConfigurationElement>> fViewLoadersList = new HashMap<String, ArrayList<IConfigurationElement>>();
  50
  51     // ------------------------------------------------------------------------
  52     // Constructor
  53     // ------------------------------------------------------------------------
  54     /**
  55      * This should not be used by the clients
  56      */
  57     private LoadersManager() {
  58     }
  59
  60     // ------------------------------------------------------------------------
  61     // Operations
  62     // ------------------------------------------------------------------------
  63     /**
  64      * A static method to get the manager instance.
  65      *
  66      * @return the manager instance
  67      */
  68     public static LoadersManager getInstance() {
  69         if (loadersManager == null) {
  70             loadersManager = new LoadersManager();
  71         }
  72         return loadersManager;
  73     }
  74
  75     /**
  76      * Creates a loader instance and associate it to the view. It requires
  77      * that the loader-view-association was created by an eclipse extension.
  78      *
  79      * @param className The name of the class to create an instance from
  80      * @param view The UML2 Sequence Diagram view instance
  81      * @return The created loader
  82      */
  83     public IUml2SDLoader createLoader(String className, SDView view) {
  84
  85         // Safety check
  86         if (view == null) {
  87             return null;
  88         }
  89
  90         String viewId = view.getViewSite().getId();
  91
  92         // Get loaders from all extensions for given view
  93         List<IConfigurationElement> loaderElements = getLoaderConfigurationElements(viewId);
  94         IConfigurationElement ce = getLoaderConfigurationElement(className, loaderElements);
  95
  96         if (ce != null) {
  97             // Assign a loader instance to this view
  98             createLoaderForView(viewId, ce);
  99             IUml2SDLoader loader = fViewLoaderMap.get(viewId);
 100             if (loader != null) {
 101                 loader.setViewer(view);
 102                 return loader;
 103             }
 104         }
 105         return null;
 106     }
 107
 108     /**
 109      * Sets the loader to null for this view, a kind of clean-up while disposing.
 110      *
 111      * @param viewId the id of the view
 112      */
 113     public void resetLoader(String viewId) {
 114         IUml2SDLoader loader = (IUml2SDLoader) fViewLoaderMap.get(viewId);
 115         if (loader != null) {
 116             loader.dispose();
 117         }
 118         fViewLoaderMap.put(viewId, null);
 119     }
 120
 121     /**
 122      * Returns the loader in use in given Sequence Diagram View
 123      *
 124      * @param viewId The Sequence Diagram viewId.
 125      * @return the current loader if any - null otherwise
 126      */
 127     public IUml2SDLoader getCurrentLoader(String viewId) {
 128         return getCurrentLoader(viewId, null);
 129     }
 130
 131     /**
 132      * Returns the loader in use in this Sequence Diagram View
 133      *
 134      * @param viewId The Sequence Diagram viewId
 135      * @param view The Sequence Diagram view (if known). Use null to reference the primary SD View.
 136      * @return the current loader if any - null otherwise
 137      */
 138     public IUml2SDLoader getCurrentLoader(String viewId, SDView view) {
 139         if (viewId == null) {
 140             return null;
 141         }
 142
 143         IWorkbenchPage persp = TmfUiPlugin.getDefault().getWorkbench().getActiveWorkbenchWindow().getActivePage();
 144
 145         SDView sdView = view;
 146
 147         try {
 148             // Search the view corresponding to the viewId
 149             if (sdView == null) {
 150                 IViewReference viewref = (IViewReference) persp.findViewReference(viewId);
 151                 if (viewref != null) {
 152                     sdView = (SDView) viewref.getView(false);
 153                 }
 154
 155                 if (sdView == null) {
 156                     // no corresponding view exists -> return null for the loader
 157                     return null;
 158                 }
 159             }
 160
 161             // Return the loader corresponding to that view (if any)
 162             IUml2SDLoader loader = fViewLoaderMap.get(viewId);
 163             if (loader == null) {
 164                 createLastLoaderIfAny(viewId);
 165                 loader = fViewLoaderMap.get(viewId);
 166             }
 167
 168             return loader;
 169         } catch (Exception e) {
 170             if (Tracer.isErrorTraced()) {
 171                 Tracer.traceError("Exception during getCurrentLoder(): " + e); //$NON-NLS-1$
 172             }
 173         }
 174         return null;
 175     }
 176
 177     /**
 178      * Returns the loader class name that have been saved last time.
 179      *
 180      * @param viewId The view this loader belongs to
 181      * @return the class name of the saved loader
 182      */
 183     public String getSavedLoader(String viewId) {
 184         IPreferenceStore p = TmfUiPlugin.getDefault().getPreferenceStore();
 185         return p.getString(LOADER_PREFIX + viewId);
 186     }
 187
 188     /**
 189      * Saves the last loader in order to reload it on next session.
 190      */
 191     public void saveLastLoader(String id, String id2) {
 192         IPreferenceStore p = TmfUiPlugin.getDefault().getPreferenceStore();
 193         p.setValue(LOADER_PREFIX + id2, id);
 194     }
 195
 196     /**
 197      * Changes the current unique loader to the given secondary viewId.
 198      *
 199      * @param loader The current loader
 200      * @param id the view secondary id or null
 201      */
 202     private void setCurrentLoader(IUml2SDLoader loader, String id) {
 203         if (id == null) {
 204             return;
 205         }
 206
 207         // Get the loader in use
 208         IUml2SDLoader currentLoader = fViewLoaderMap.get(id);
 209
 210         if ((currentLoader != null) && (currentLoader != loader)) {
 211             if (loader != null) {
 212                 IWorkbenchPage persp = TmfUiPlugin.getDefault().getWorkbench().getActiveWorkbenchWindow().getActivePage();
 213                 try {
 214                     // Search view corresponding to the viewId
 215                     SDView sdview = null;
 216                     IViewReference viewref = (IViewReference) persp.findViewReference(id);
 217                     if (viewref != null) {
 218                         sdview = (SDView) viewref.getView(false);
 219                     }
 220
 221                     // Make everything clean for the new loader
 222                     if (sdview != null) {
 223                         sdview.resetProviders();
 224                     }
 225
 226                 } catch (Exception e) {
 227                     e.printStackTrace();
 228                 }
 229             }
 230             // The old loader is going to be kicked
 231             currentLoader.dispose();
 232         }
 233
 234         // Replace the current loader by the new one in the map
 235         fViewLoaderMap.put(id, loader);
 236
 237         // Store this loader in the preferences to be able to restore it when the workbench will be re-launched
 238         if (loader != null) {
 239             saveLastLoader(loader.getClass().getName(), id);
 240         }
 241     }
 242
 243     /**
 244      * Creates the last loader and saves it. If not last is not available, it creates
 245      * and saves the default loader, else no loader is created.
 246      *
 247      * @param viewId The view ID.
 248      */
 249     private void createLastLoaderIfAny(String viewId) {
 250         // Get saved loader from preferences
 251         String loaderName = getSavedLoader(viewId);
 252
 253         // Get loaders from all extensions for given view
 254         List<IConfigurationElement> loaderElements = getLoaderConfigurationElements(viewId);
 255         IConfigurationElement ce = getLoaderConfigurationElement(loaderName, loaderElements);
 256
 257         if (ce == null) {
 258             ce = getDefaultLoader(loaderElements);
 259         }
 260
 261         if (ce != null) {
 262             createLoaderForView(viewId, ce);
 263         }
 264     }
 265
 266     /**
 267      * Gets a list of loader configuration elements from the extension point registry for a given view.
 268      * @param viewId The view ID
 269      * @return List of extension point configuration elements.
 270      */
 271     private List<IConfigurationElement> getLoaderConfigurationElements(String viewId) {
 272         List<IConfigurationElement> list = (List<IConfigurationElement>) fViewLoadersList.get(viewId);
 273         if (list != null) {
 274             return list;
 275         }
 276         ArrayList<IConfigurationElement> ret = new ArrayList<IConfigurationElement>();
 277         IExtensionPoint iep = Platform.getExtensionRegistry().getExtensionPoint(TmfUiPlugin.PLUGIN_ID, LOADER_TAG);
 278         if (iep == null) {
 279             return ret;
 280         }
 281
 282         IExtension[] ie = iep.getExtensions();
 283         if (ie == null) {
 284             return ret;
 285         }
 286
 287         for (int i = 0; i < ie.length; i++) {
 288             IConfigurationElement c[] = ie[i].getConfigurationElements();
 289             for (int j = 0; j < c.length; j++) {
 290                 if (viewId.equals(c[j].getAttribute("view"))) { //$NON-NLS-1$
 291                     ret.add(c[j]);
 292                 }
 293             }
 294         }
 295         fViewLoadersList.put(viewId, ret);
 296         return ret;
 297     }
 298
 299     /**
 300      * Returns the loader configuration element for given loader class name and for the given
 301      * list of configuration elements, if available else null.
 302      *
 303      * @param loaderClassName The loader class name.
 304      * @param loaderElements  The list of loader configuration elements
 305      * @return Extension point configuration element
 306      */
 307     private IConfigurationElement getLoaderConfigurationElement(String loaderClassName, List<IConfigurationElement> loaderElements) {
 308         if (loaderClassName != null && loaderClassName.length() > 0) {
 309             // Find configuration element corresponding to the saved loader
 310             for (Iterator<IConfigurationElement> i = loaderElements.iterator(); i.hasNext();) {
 311                 IConfigurationElement ce = (IConfigurationElement) i.next();
 312                 if (ce.getAttribute("class").equals(loaderClassName)) { //$NON-NLS-1$
 313                     return ce;
 314                 }
 315             }
 316         }
 317         return null;
 318     }
 319
 320     /**
 321      * Returns the loader configuration element for the given list of configuration elements, if available else null.
 322      * Note that if multiple default loaders are defined it selects the first one
 323
 324      * @param loaderElements The list of loader configuration elements
 325      * @return The default extension point configuration element.
 326      */
 327     private IConfigurationElement getDefaultLoader(List<IConfigurationElement> loaderElements) {
 328         // Look for a default loader
 329         for (Iterator<IConfigurationElement> i = loaderElements.iterator(); i.hasNext();) {
 330             IConfigurationElement ce = (IConfigurationElement) i.next();
 331             if (Boolean.valueOf(ce.getAttribute("default")).booleanValue()) { //$NON-NLS-1$
 332                 return ce;
 333             }
 334         }
 335         return null;
 336     }
 337
 338     /**
 339      * Creates an instance of the loader class for a given extension point configuration element and
 340      * also sets it as current loader for the given view.
 341      * @param viewId The view ID.
 342      * @param ce The extension point configuration element
 343      */
 344     private void createLoaderForView(String viewId, IConfigurationElement ce) {
 345         try {
 346             Object obj = ce.createExecutableExtension("class"); //$NON-NLS-1$
 347             IUml2SDLoader l = (IUml2SDLoader) obj;
 348             if (viewId != null) {
 349                 setCurrentLoader(l, viewId);
 350             }
 351         } catch (CoreException e4) {
 352             System.err.println("Error 'uml2SDLoader' Extension point :" + e4); //$NON-NLS-1$
 353         } catch (Exception e5) {
 354             e5.printStackTrace();
 355             System.err.println("Error 'uml2SDLoader' Extension point :" + e5); //$NON-NLS-1$
 356         }
 357     }
 358 }