net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/externaltools/internal/registry/ExternalToolVariableRegistry.java

   1 package net.sourceforge.phpdt.externaltools.internal.registry;
   2
   3 /**********************************************************************
   4 Copyright (c) 2002 IBM Corp. and others. All rights reserved.
   5 This file is made available under the terms of the Common Public License v1.0
   6 which accompanies this distribution, and is available at
   7 http://www.eclipse.org/legal/cpl-v10.html
   8
   9 Contributors:
  10 **********************************************************************/
  11
  12 import java.util.HashMap;
  13
  14 import org.eclipse.core.runtime.IConfigurationElement;
  15 import org.eclipse.core.runtime.IExtension;
  16 import org.eclipse.core.runtime.IExtensionPoint;
  17 import org.eclipse.core.runtime.IPluginRegistry;
  18 import org.eclipse.core.runtime.Platform;
  19 import net.sourceforge.phpdt.externaltools.internal.model.ExternalToolsPlugin;
  20 import net.sourceforge.phpdt.externaltools.model.IExternalToolConstants;
  21
  22 /**
  23  * General registry reader for external tool variables.
  24  */
  25 public abstract class ExternalToolVariableRegistry {
  26         // Format of the variable extension points
  27         // <extension point="org.eclipse.ui.externalTools.***Variables>
  28         //              <variable
  29         //                      tag={string}
  30         //                      description={string}
  31         //                      componentClass={string:IVariableComponent}
  32         //                      expanderClass={string:IVariable***Expander}>
  33         //              </variable>
  34         // </extension>
  35         //
  36
  37         /**
  38          * Element and attribute tags of a variable extension.
  39          */
  40         /*package*/ static final String TAG_VARIABLE = "variable"; //$NON-NLS-1$
  41         /*package*/ static final String TAG_TAG = "tag"; //$NON-NLS-1$
  42         /*package*/ static final String TAG_DESCRIPTION = "description"; //$NON-NLS-1$
  43         /*package*/ static final String TAG_COMPONENT_CLASS = "componentClass"; //$NON-NLS-1$
  44         /*package*/ static final String TAG_EXPANDER_CLASS = "expanderClass"; //$NON-NLS-1$
  45
  46
  47         /**
  48          * Table of variables where the key is the variable tag
  49          * and the value is the corresponding variable.
  50          */
  51         private HashMap variables;
  52
  53         /**
  54          * The extension point id to read the variables from
  55          */
  56         private String extensionPointId;
  57
  58         /**
  59          * The
  60         /**
  61          * Creates a new registry and loads the variables.
  62          */
  63         public ExternalToolVariableRegistry(String extensionPointId) {
  64                 super();
  65                 this.extensionPointId = extensionPointId;
  66                 loadVariables();
  67         }
  68
  69         /**
  70          * Returns the variables in the registry
  71          */
  72         protected final void copyVariables(Object[] results) {
  73                 variables.values().toArray(results);
  74         }
  75
  76         /**
  77          * Returns the variable for the specified tag, or
  78          * <code>null</code> if none found.
  79          */
  80         protected final ExternalToolVariable findVariable(String tag) {
  81                 return (ExternalToolVariable) variables.get(tag);
  82         }
  83
  84         /**
  85          * Returns the number of variables in the registry.
  86          */
  87         public final int getVariableCount() {
  88                 return variables.size();
  89         }
  90
  91         /**
  92          * Load the available variables
  93          */
  94         private void loadVariables() {
  95                 variables = new HashMap();
  96                 IPluginRegistry registry = Platform.getPluginRegistry();
  97                 IExtensionPoint point = registry.getExtensionPoint(IExternalToolConstants.PLUGIN_ID, extensionPointId);
  98                 if (point != null) {
  99                         IExtension[] extensions = point.getExtensions();
 100                         for (int i = 0; i < extensions.length; i++) {
 101                                 IConfigurationElement[] elements = extensions[i].getConfigurationElements();
 102                                 for (int j = 0; j < elements.length; j++) {
 103                                         IConfigurationElement element = elements[j];
 104                                         if (element.getName().equals(TAG_VARIABLE)) {
 105                                                 String tag = element.getAttribute(TAG_TAG);
 106                                                 String description = element.getAttribute(TAG_DESCRIPTION);
 107                                                 String className = element.getAttribute(TAG_EXPANDER_CLASS);
 108
 109                                                 boolean valid = true;
 110                                                 if (tag == null || tag.length() == 0) {
 111                                                         valid = false;
 112                                                         ExternalToolsPlugin.getDefault().log("Missing tag attribute value for variable element.", null); //$NON-NLS-1$
 113                                                 }
 114                                                 if (description == null || description.length() == 0) {
 115                                                         valid = false;
 116                                                         ExternalToolsPlugin.getDefault().log("Missing description attribute value for variable element.", null); //$NON-NLS-1$
 117                                                 }
 118                                                 if (className == null || className.length() == 0) {
 119                                                         valid = false;
 120                                                         ExternalToolsPlugin.getDefault().log("Missing expander class attribute value for variable element.", null); //$NON-NLS-1$
 121                                                 }
 122
 123                                                 if (valid)
 124                                                         variables.put(tag, newVariable(tag, description, element));
 125                                         }
 126                                 }
 127                         }
 128                 }
 129         }
 130
 131         /**
 132          * Creates a new variable from the specified information.
 133          */
 134         protected abstract ExternalToolVariable newVariable(String tag, String description, IConfigurationElement element);
 135 }