net.sourceforge.phpeclipse.ui/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 import net.sourceforge.phpeclipse.PHPeclipsePlugin;
  21 import net.sourceforge.phpeclipse.ui.WebUI;
  22
  23 import org.eclipse.core.runtime.CoreException;
  24 import org.eclipse.core.runtime.IConfigurationElement;
  25 import org.eclipse.core.runtime.IExtensionRegistry;
  26 import org.eclipse.core.runtime.Platform;
  27
  28 /**
  29  * @since 3.0
  30  */
  31 public class JavaFoldingStructureProviderRegistry {
  32
  33         private static final String EXTENSION_POINT = "foldingStructureProviders"; //$NON-NLS-1$
  34
  35         /** The map of descriptors, indexed by their identifiers. */
  36         private Map fDescriptors;
  37
  38         /**
  39          * Creates a new instance.
  40          */
  41         public JavaFoldingStructureProviderRegistry() {
  42         }
  43
  44         /**
  45          * Returns an array of <code>IJavaFoldingProviderDescriptor</code>
  46          * describing all extension to the <code>foldingProviders</code> extension
  47          * point.
  48          *
  49          * @return the list of extensions to the
  50          *         <code>quickDiffReferenceProvider</code> extension point.
  51          */
  52         public JavaFoldingStructureProviderDescriptor[] getFoldingProviderDescriptors() {
  53                 synchronized (this) {
  54                         ensureRegistered();
  55                         return (JavaFoldingStructureProviderDescriptor[]) fDescriptors
  56                                         .values()
  57                                         .toArray(
  58                                                         new JavaFoldingStructureProviderDescriptor[fDescriptors
  59                                                                         .size()]);
  60                 }
  61         }
  62
  63         /**
  64          * Returns the folding provider with identifier <code>id</code> or
  65          * <code>null</code> if no such provider is registered.
  66          *
  67          * @param id
  68          *            the identifier for which a provider is wanted
  69          * @return the corresponding provider, or <code>null</code> if none can be
  70          *         found
  71          */
  72         public JavaFoldingStructureProviderDescriptor getFoldingProviderDescriptor(
  73                         String id) {
  74                 synchronized (this) {
  75                         ensureRegistered();
  76                         return (JavaFoldingStructureProviderDescriptor) fDescriptors
  77                                         .get(id);
  78                 }
  79         }
  80
  81         /**
  82          * Instantiates and returns the provider that is currently configured in the
  83          * preferences.
  84          *
  85          * @return the current provider according to the preferences
  86          */
  87         public IJavaFoldingStructureProvider getCurrentFoldingProvider() {
  88                 String id = WebUI.getDefault().getPreferenceStore()
  89                                 .getString(PreferenceConstants.EDITOR_FOLDING_PROVIDER);
  90                 JavaFoldingStructureProviderDescriptor desc = getFoldingProviderDescriptor(id);
  91                 if (desc != null) {
  92                         try {
  93                                 return desc.createProvider();
  94                         } catch (CoreException e) {
  95                                 WebUI.log(e);
  96                         }
  97                 }
  98                 return null;
  99         }
 100
 101         /**
 102          * Ensures that the extensions are read and stored in
 103          * <code>fDescriptors</code>.
 104          */
 105         private void ensureRegistered() {
 106                 if (fDescriptors == null)
 107                         reloadExtensions();
 108         }
 109
 110         /**
 111          * Reads all extensions.
 112          * <p>
 113          * This method can be called more than once in order to reload from a
 114          * changed extension registry.
 115          * </p>
 116          */
 117         public void reloadExtensions() {
 118                 IExtensionRegistry registry = Platform.getExtensionRegistry();
 119                 Map map = new HashMap();
 120
 121                 IConfigurationElement[] elements = registry
 122                                 .getConfigurationElementsFor(PHPeclipsePlugin.getPluginId(),
 123                                                 EXTENSION_POINT);
 124                 for (int i = 0; i < elements.length; i++) {
 125                         JavaFoldingStructureProviderDescriptor desc = new JavaFoldingStructureProviderDescriptor(
 126                                         elements[i]);
 127                         map.put(desc.getId(), desc);
 128                 }
 129
 130                 synchronized (this) {
 131                         fDescriptors = Collections.unmodifiableMap(map);
 132                 }
 133         }
 134
 135 }