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 net.sourceforge.phpdt.externaltools.internal.model.ExternalToolsPlugin;
  15 import net.sourceforge.phpdt.externaltools.model.IExternalToolConstants;
  16
  17 import org.eclipse.core.runtime.IConfigurationElement;
  18 import org.eclipse.core.runtime.IExtension;
  19 import org.eclipse.core.runtime.IExtensionPoint;
  20 import org.eclipse.core.runtime.IPluginRegistry;
  21 import org.eclipse.core.runtime.Platform;
  22
  23 /**
  24  * General registry reader for external tool variables.
  25  */
  26 public abstract class ExternalToolVariableRegistry {
  27         // Format of the variable extension points
  28         // <extension point="org.eclipse.ui.externalTools.***Variables>
  29         //              <variable
  30         //                      tag={string}
  31         //                      description={string}
  32         //                      componentClass={string:IVariableComponent}
  33         //                      expanderClass={string:IVariable***Expander}>
  34         //              </variable>
  35         // </extension>
  36         //
  37
  38         /**
  39          * Element and attribute tags of a variable extension.
  40          */
  41         /*package*/ static final String TAG_VARIABLE = "variable"; //$NON-NLS-1$
  42         /*package*/ static final String TAG_TAG = "tag"; //$NON-NLS-1$
  43         /*package*/ static final String TAG_DESCRIPTION = "description"; //$NON-NLS-1$
  44         /*package*/ static final String TAG_COMPONENT_CLASS = "componentClass"; //$NON-NLS-1$
  45         /*package*/ static final String TAG_EXPANDER_CLASS = "expanderClass"; //$NON-NLS-1$
  46
  47
  48         /**
  49          * Table of variables where the key is the variable tag
  50          * and the value is the corresponding variable.
  51          */
  52         private HashMap variables;
  53
  54         /**
  55          * The extension point id to read the variables from
  56          */
  57         private String extensionPointId;
  58
  59         /**
  60          * The
  61         /**
  62          * Creates a new registry and loads the variables.
  63          */
  64         public ExternalToolVariableRegistry(String extensionPointId) {
  65                 super();
  66                 this.extensionPointId = extensionPointId;
  67                 loadVariables();
  68         }
  69
  70         /**
  71          * Returns the variables in the registry
  72          */
  73         protected final void copyVariables(Object[] results) {
  74                 variables.values().toArray(results);
  75         }
  76
  77         /**
  78          * Returns the variable for the specified tag, or
  79          * <code>null</code> if none found.
  80          */
  81         protected final ExternalToolVariable findVariable(String tag) {
  82                 return (ExternalToolVariable) variables.get(tag);
  83         }
  84
  85         /**
  86          * Returns the number of variables in the registry.
  87          */
  88         public final int getVariableCount() {
  89                 return variables.size();
  90         }
  91
  92         /**
  93          * Load the available variables
  94          */
  95         private void loadVariables() {
  96                 variables = new HashMap();
  97                 IPluginRegistry registry = Platform.getPluginRegistry();
  98                 IExtensionPoint point = registry.getExtensionPoint(IExternalToolConstants.PLUGIN_ID, extensionPointId);
  99                 if (point != null) {
 100                         IExtension[] extensions = point.getExtensions();
 101                         for (int i = 0; i < extensions.length; i++) {
 102                                 IConfigurationElement[] elements = extensions[i].getConfigurationElements();
 103                                 for (int j = 0; j < elements.length; j++) {
 104                                         IConfigurationElement element = elements[j];
 105                                         if (element.getName().equals(TAG_VARIABLE)) {
 106                                                 String tag = element.getAttribute(TAG_TAG);
 107                                                 String description = element.getAttribute(TAG_DESCRIPTION);
 108                                                 String className = element.getAttribute(TAG_EXPANDER_CLASS);
 109
 110                                                 boolean valid = true;
 111                                                 if (tag == null || tag.length() == 0) {
 112                                                         valid = false;
 113                                                         ExternalToolsPlugin.getDefault().log("Missing tag attribute value for variable element.", null); //$NON-NLS-1$
 114                                                 }
 115                                                 if (description == null || description.length() == 0) {
 116                                                         valid = false;
 117                                                         ExternalToolsPlugin.getDefault().log("Missing description attribute value for variable element.", null); //$NON-NLS-1$
 118                                                 }
 119                                                 if (className == null || className.length() == 0) {
 120                                                         valid = false;
 121                                                         ExternalToolsPlugin.getDefault().log("Missing expander class attribute value for variable element.", null); //$NON-NLS-1$
 122                                                 }
 123
 124                                                 if (valid)
 125                                                         variables.put(tag, newVariable(tag, description, element));
 126                                         }
 127                                 }
 128                         }
 129                 }
 130         }
 131
 132         /**
 133          * Creates a new variable from the specified information.
 134          */
 135         protected abstract ExternalToolVariable newVariable(String tag, String description, IConfigurationElement element);
 136 }