net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/text/folding/JavaFoldingStructureProviderRegistry.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.ui.text.folding;
  12
  13 import java.util.Collections;
  14 import java.util.HashMap;
  15 import java.util.Map;
  16
  17 import net.sourceforge.phpdt.ui.PreferenceConstants;
  18 import net.sourceforge.phpdt.ui.text.folding.IJavaFoldingStructureProvider;
  19 import net.sourceforge.phpeclipse.PHPeclipsePlugin;
  20
  21 import org.eclipse.core.runtime.CoreException;
  22 import org.eclipse.core.runtime.IConfigurationElement;
  23 import org.eclipse.core.runtime.IExtensionRegistry;
  24 import org.eclipse.core.runtime.Platform;
  25
  26 /**
  27  * @since 3.0
  28  */
  29 public class JavaFoldingStructureProviderRegistry {
  30
  31         private static final String EXTENSION_POINT= "foldingStructureProviders"; //$NON-NLS-1$
  32
  33         /** The map of descriptors, indexed by their identifiers. */
  34         private Map fDescriptors;
  35
  36         /**
  37          * Creates a new instance.
  38          */
  39         public JavaFoldingStructureProviderRegistry() {
  40         }
  41
  42         /**
  43          * Returns an array of <code>IJavaFoldingProviderDescriptor</code> describing
  44          * all extension to the <code>foldingProviders</code> extension point.
  45          *
  46          * @return the list of extensions to the
  47          *         <code>quickDiffReferenceProvider</code> extension point.
  48          */
  49         public JavaFoldingStructureProviderDescriptor[] getFoldingProviderDescriptors() {
  50                 synchronized (this) {
  51                         ensureRegistered();
  52                         return (JavaFoldingStructureProviderDescriptor[]) fDescriptors.values().toArray(new JavaFoldingStructureProviderDescriptor[fDescriptors.size()]);
  53                 }
  54         }
  55
  56         /**
  57          * Returns the folding provider with identifier <code>id</code> or
  58          * <code>null</code> if no such provider is registered.
  59          *
  60          * @param id the identifier for which a provider is wanted
  61          * @return the corresponding provider, or <code>null</code> if none can be
  62          *         found
  63          */
  64         public JavaFoldingStructureProviderDescriptor getFoldingProviderDescriptor(String id) {
  65                 synchronized (this) {
  66                         ensureRegistered();
  67                         return (JavaFoldingStructureProviderDescriptor) fDescriptors.get(id);
  68                 }
  69         }
  70
  71         /**
  72          * Instantiates and returns the provider that is currently configured in the
  73          * preferences.
  74          *
  75          * @return the current provider according to the preferences
  76          */
  77         public IJavaFoldingStructureProvider getCurrentFoldingProvider() {
  78                 String id= PHPeclipsePlugin.getDefault().getPreferenceStore().getString(PreferenceConstants.EDITOR_FOLDING_PROVIDER);
  79                 JavaFoldingStructureProviderDescriptor desc= getFoldingProviderDescriptor(id);
  80                 if (desc != null) {
  81                         try {
  82                                 return desc.createProvider();
  83                         } catch (CoreException e) {
  84                           PHPeclipsePlugin.log(e);
  85                         }
  86                 }
  87                 return null;
  88         }
  89
  90         /**
  91          * Ensures that the extensions are read and stored in
  92          * <code>fDescriptors</code>.
  93          */
  94         private void ensureRegistered() {
  95                 if (fDescriptors == null)
  96                         reloadExtensions();
  97         }
  98
  99         /**
 100          * Reads all extensions.
 101          * <p>
 102          * This method can be called more than once in
 103          * order to reload from a changed extension registry.
 104          * </p>
 105          */
 106         public void reloadExtensions() {
 107                 IExtensionRegistry registry= Platform.getExtensionRegistry();
 108                 Map map= new HashMap();
 109
 110                 IConfigurationElement[] elements= registry.getConfigurationElementsFor(PHPeclipsePlugin.getPluginId(), EXTENSION_POINT);
 111                 for (int i= 0; i < elements.length; i++) {
 112                         JavaFoldingStructureProviderDescriptor desc= new JavaFoldingStructureProviderDescriptor(elements[i]);
 113                         map.put(desc.getId(), desc);
 114                 }
 115
 116                 synchronized(this) {
 117                         fDescriptors= Collections.unmodifiableMap(map);
 118                 }
 119         }
 120
 121 }