expose IContextContributor as extension pointrefs/changes/53/6053/8

This changes exposes IContextContributor registrations
as an org.eclipse.mylyn.context.core extension point.

Bug: 378399
Change-Id: I62b2c4c3400d951b8dc800cd98b993bdcb03df85

6 files changed, 147 insertions, 7 deletions

diff --git a/org.eclipse.mylyn.context.core/plugin.xml b/org.eclipse.mylyn.context.core/plugin.xml
index 6d7e01b..bf7733b 100644
--- a/org.eclipse.mylyn.context.core/plugin.xml
+++ b/org.eclipse.mylyn.context.core/plugin.xml
@@ -8,9 +8,11 @@
    
     Contributors:
          Tasktop Technologies - initial API and implementation
+         Sebastian Schmidt - added contributor extension point
  -->
 
 <plugin>
+   <extension-point id="contributor" name="contributor" schema="schema/contributor.exsd"/>
    <extension-point id="bridges" name="bridges" schema="schema/bridges.exsd"/>
    <extension-point id="internalBridges" name="Internal Bridges" schema="schema/internalBridges.exsd"/>
    <extension-point id="relationProviders" name="relationProviders" schema="schema/relationProviders.exsd"/>
diff --git a/org.eclipse.mylyn.context.core/schema/contributor.exsd b/org.eclipse.mylyn.context.core/schema/contributor.exsd
new file mode 100644
index 0000000..ee0c1f7
--- a/dev/null
+++ b/org.eclipse.mylyn.context.core/schema/contributor.exsd
@@ -0,0 +1,95 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<!-- Schema file written by PDE -->
+<schema targetNamespace="org.eclipse.mylyn.context.core" xmlns="http://www.w3.org/2001/XMLSchema">
+<annotation>
+      <appInfo>
+         <meta.schema plugin="org.eclipse.mylyn.context.core" id="contributor" name="contributor"/>
+      </appInfo>
+      <documentation>
+         ContextContributor are allowed to persist arbitrary data in context.
+      </documentation>
+   </annotation>
+
+   <element name="extension">
+      <annotation>
+         <appInfo>
+            <meta.element />
+         </appInfo>
+      </annotation>
+      <complexType>
+         <sequence>
+            <element ref="contextContributor" minOccurs="0" maxOccurs="unbounded"/>
+         </sequence>
+         <attribute name="point" type="string" use="required">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+            </annotation>
+         </attribute>
+         <attribute name="id" type="string">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+            </annotation>
+         </attribute>
+         <attribute name="name" type="string">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+               <appInfo>
+                  <meta.attribute translatable="true"/>
+               </appInfo>
+            </annotation>
+         </attribute>
+      </complexType>
+   </element>
+
+   <element name="contextContributor">
+      <complexType>
+         <attribute name="name" type="string">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+               <appInfo>
+                  <meta.attribute translatable="true"/>
+               </appInfo>
+            </annotation>
+         </attribute>
+         <attribute name="id" type="string">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+            </annotation>
+         </attribute>
+         <attribute name="class" type="string" use="required">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+               <appInfo>
+                  <meta.attribute kind="java" basedOn="org.eclipse.mylyn.context.core.AbstractContextContributor:"/>
+               </appInfo>
+            </annotation>
+         </attribute>
+      </complexType>
+   </element>
+
+   <annotation>
+      <appInfo>
+         <meta.section type="since"/>
+      </appInfo>
+      <documentation>
+         3.8
+      </documentation>
+   </annotation>
+
+
+
+
+
+</schema>
diff --git a/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/AbstractContextContributor.java b/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/AbstractContextContributor.java
new file mode 100644
index 0000000..93abac3
--- a/dev/null
+++ b/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/AbstractContextContributor.java
@@ -0,0 +1,21 @@
+/*******************************************************************************
+ * Copyright (c) 2012 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Sebastian Schmidt - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.context.core;
+
+/**
+ * Clients should extend this class instead of implementing {@link IContextContributor}.
+ * 
+ * @since 3.9
+ */
+public abstract class AbstractContextContributor implements IContextContributor {
+
+}
\ No newline at end of file
diff --git a/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/ContextCore.java b/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/ContextCore.java
index 2ae4613..8a0d572 100644
--- a/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/ContextCore.java
+++ b/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/ContextCore.java
@@ -59,6 +59,9 @@ public final class ContextCore {
 	}
 
 	/**
+	 * Returns a list of all {@link IContextContributor} registered with Mylyn context. Please refer to the
+	 * org.eclipse.mylyn.context.core.contributor extension point.
+	 * 
 	 * @since 3.9
 	 */
 	public static List<IContextContributor> getContextContributor() {
diff --git a/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/internal/context/core/ContextCorePlugin.java b/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/internal/context/core/ContextCorePlugin.java
index fe7ecf8..ce46d9f 100644
--- a/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/internal/context/core/ContextCorePlugin.java
+++ b/org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/internal/context/core/ContextCorePlugin.java
@@ -31,7 +31,9 @@ import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Plugin;
 import org.eclipse.core.runtime.Status;
+import org.eclipse.mylyn.commons.core.ExtensionPointReader;
 import org.eclipse.mylyn.commons.core.StatusHandler;
+import org.eclipse.mylyn.context.core.AbstractContextContributor;
 import org.eclipse.mylyn.context.core.AbstractContextStructureBridge;
 import org.eclipse.mylyn.context.core.ContextCore;
 import org.eclipse.mylyn.context.core.IContextContributor;
@@ -52,7 +54,7 @@ public class ContextCorePlugin extends Plugin {
 
 	private final Map<String, Set<String>> childContentTypeMap = new ConcurrentHashMap<String, Set<String>>();
 
-	private final List<IContextContributor> contextContributor = new CopyOnWriteArrayList<IContextContributor>();
+	private List<IContextContributor> contextContributor = new CopyOnWriteArrayList<IContextContributor>();
 
 	// specifies that one content type should shadow another
 	// the <value> content type shadows the <key> content typee
@@ -70,6 +72,8 @@ public class ContextCorePlugin extends Plugin {
 
 	private final InteractionContextScaling commonContextScaling = new InteractionContextScaling();
 
+	private boolean contextContributorInitialized = false;
+
 	private static final AbstractContextStructureBridge DEFAULT_BRIDGE = new AbstractContextStructureBridge() {
 
 		@Override
@@ -133,6 +137,10 @@ public class ContextCorePlugin extends Plugin {
 		}
 	};
 
+	private static final String EXTENSION_ELEMENT_CONTRIBUTOR = "contextContributor"; //$NON-NLS-1$
+
+	private static final String EXTENSION_ID_CONTRIBUTOR = "contributor"; //$NON-NLS-1$
+
 	public ContextCorePlugin() {
 		INSTANCE = this;
 	}
@@ -215,15 +223,26 @@ public class ContextCorePlugin extends Plugin {
 	}
 
 	public List<IContextContributor> getContextContributor() {
+		initContextContributor();
 		return contextContributor;
 	}
 
-	// TODO: add extension point to register context provider
-	public void addContextContributor(IContextContributor contributor) {
+	private void initContextContributor() {
+		if (!contextContributorInitialized) {
+			ExtensionPointReader<IContextContributor> extensionPointReader = new ExtensionPointReader<IContextContributor>(
+					ContextCorePlugin.ID_PLUGIN, ContextCorePlugin.EXTENSION_ID_CONTRIBUTOR,
+					ContextCorePlugin.EXTENSION_ELEMENT_CONTRIBUTOR, IContextContributor.class);
+			extensionPointReader.read();
+			contextContributor = extensionPointReader.getItems();
+			contextContributorInitialized = true;
+		}
+	}
+
+	public void addContextContributor(AbstractContextContributor contributor) {
 		contextContributor.add(contributor);
 	}
 
-	public void removeContextContributor(IContextContributor contributor) {
+	public void removeContextContributor(AbstractContextContributor contributor) {
 		contextContributor.remove(contributor);
 	}
 
diff --git a/org.eclipse.mylyn.context.tests/src/org/eclipse/mylyn/context/tests/ContextExternalizerTest.java b/org.eclipse.mylyn.context.tests/src/org/eclipse/mylyn/context/tests/ContextExternalizerTest.java
index e5eb933..3a48531 100644
--- a/org.eclipse.mylyn.context.tests/src/org/eclipse/mylyn/context/tests/ContextExternalizerTest.java
+++ b/org.eclipse.mylyn.context.tests/src/org/eclipse/mylyn/context/tests/ContextExternalizerTest.java
@@ -24,8 +24,8 @@ import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
 import org.eclipse.mylyn.commons.sdk.util.CommonTestUtil;
+import org.eclipse.mylyn.context.core.AbstractContextContributor;
 import org.eclipse.mylyn.context.core.ContextCore;
-import org.eclipse.mylyn.context.core.IContextContributor;
 import org.eclipse.mylyn.context.core.IInteractionContext;
 import org.eclipse.mylyn.context.core.IInteractionContextScaling;
 import org.eclipse.mylyn.context.core.IInteractionElement;
@@ -314,7 +314,7 @@ public class ContextExternalizerTest extends AbstractContextTest {
 	public void testAddContextContributor() throws Exception {
 		InteractionContextExternalizer externalizer = new InteractionContextExternalizer();
 		ContextCorePlugin contextCorePlugin = ContextCorePlugin.getDefault();
-		IContextContributor contributor = mock(IContextContributor.class);
+		AbstractContextContributor contributor = mock(AbstractContextContributor.class);
 		when(contributor.getDataAsStream(context)).thenReturn(null);
 
 		contextCorePlugin.addContextContributor(contributor);
@@ -330,7 +330,7 @@ public class ContextExternalizerTest extends AbstractContextTest {
 
 	public void testWriteAdditionalContextData() throws Exception {
 		InteractionContextExternalizer externalizer = new InteractionContextExternalizer();
-		IContextContributor contributor = mock(IContextContributor.class);
+		AbstractContextContributor contributor = mock(AbstractContextContributor.class);
 		InteractionEvent event = mockNavigation("InteractionEvent");
 		context.parseEvent(event);