net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/folding/JavaFoldingStructureProviderDescriptor.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 net.sourceforge.phpdt.ui.text.folding.IJavaFoldingPreferenceBlock;
  14 import net.sourceforge.phpdt.ui.text.folding.IJavaFoldingStructureProvider;
  15
  16 import org.eclipse.core.runtime.CoreException;
  17 import org.eclipse.core.runtime.IConfigurationElement;
  18 import org.eclipse.jface.text.Assert;
  19
  20 /**
  21  * Describes a contribution to the folding provider extension point.
  22  *
  23  * @since 3.0
  24  */
  25 public final class JavaFoldingStructureProviderDescriptor {
  26
  27         /* extension point attribute names */
  28
  29         private static final String PREFERENCES_CLASS = "preferencesClass"; //$NON-NLS-1$
  30
  31         private static final String CLASS = "class"; //$NON-NLS-1$
  32
  33         private static final String NAME = "name"; //$NON-NLS-1$
  34
  35         private static final String ID = "id"; //$NON-NLS-1$
  36
  37         /** The identifier of the extension. */
  38         private String fId;
  39
  40         /** The name of the extension. */
  41         private String fName;
  42
  43         /** The class name of the provided <code>IJavaFoldingStructureProvider</code>. */
  44         private String fClass;
  45
  46         /**
  47          * <code>true</code> if the extension specifies a custom
  48          * <code>IJavaFoldingPreferenceBlock</code>.
  49          */
  50         private boolean fHasPreferences;
  51
  52         /** The configuration element of this extension. */
  53         private IConfigurationElement fElement;
  54
  55         /**
  56          * Creates a new descriptor.
  57          *
  58          * @param element
  59          *            the configuration element to read
  60          */
  61         JavaFoldingStructureProviderDescriptor(IConfigurationElement element) {
  62                 fElement = element;
  63                 fId = element.getAttributeAsIs(ID);
  64                 Assert.isLegal(fId != null);
  65
  66                 fName = element.getAttribute(NAME);
  67                 if (fName == null)
  68                         fName = fId;
  69
  70                 fClass = element.getAttributeAsIs(CLASS);
  71                 Assert.isLegal(fClass != null);
  72
  73                 if (element.getAttributeAsIs(PREFERENCES_CLASS) == null)
  74                         fHasPreferences = false;
  75                 else
  76                         fHasPreferences = true;
  77         }
  78
  79         /**
  80          * Creates a folding provider as described in the extension's xml.
  81          *
  82          * @return a new instance of the folding provider described by this
  83          *         descriptor
  84          * @throws CoreException
  85          *             if creation fails
  86          */
  87         public IJavaFoldingStructureProvider createProvider() throws CoreException {
  88                 IJavaFoldingStructureProvider prov = (IJavaFoldingStructureProvider) fElement
  89                                 .createExecutableExtension(CLASS);
  90                 return prov;
  91         }
  92
  93         /**
  94          * Creates a preferences object as described in the extension's xml.
  95          *
  96          * @return a new instance of the reference provider described by this
  97          *         descriptor
  98          * @throws CoreException
  99          *             if creation fails
 100          */
 101         public IJavaFoldingPreferenceBlock createPreferences() throws CoreException {
 102                 if (fHasPreferences) {
 103                         IJavaFoldingPreferenceBlock prefs = (IJavaFoldingPreferenceBlock) fElement
 104                                         .createExecutableExtension(PREFERENCES_CLASS);
 105                         return prefs;
 106                 } else {
 107                         return new EmptyJavaFoldingPreferenceBlock();
 108                 }
 109         }
 110
 111         /**
 112          * Returns the identifier of the described extension.
 113          *
 114          * @return Returns the id
 115          */
 116         public String getId() {
 117                 return fId;
 118         }
 119
 120         /**
 121          * Returns the name of the described extension.
 122          *
 123          * @return Returns the name
 124          */
 125         public String getName() {
 126                 return fName;
 127         }
 128 }