### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.ui
Index: schema/javaCompletionProposalComputer.exsd
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.ui/schema/javaCompletionProposalComputer.exsd,v
retrieving revision 1.8
diff -u -r1.8 javaCompletionProposalComputer.exsd
--- schema/javaCompletionProposalComputer.exsd	18 Apr 2008 06:23:21 -0000	1.8
+++ schema/javaCompletionProposalComputer.exsd	28 Dec 2011 15:27:58 -0000
@@ -7,13 +7,20 @@
       </appInfo>
       <documentation>
          This extension point allows to contribute Java completion proposal computers to participate in the content assist process of the Java editor.
+&lt;p&gt;
+This extension point supports the &lt;code&gt;enablement&lt;/code&gt; tag. Properties to test on are:
+&lt;dl&gt;
+&lt;li&gt;project: type IJavaProject; the current project&lt;/li&gt;
+&lt;/dl&gt;
       </documentation>
    </annotation>
 
+   <include schemaLocation="schema://org.eclipse.core.expressions/schema/expressionLanguage.exsd"/>
+
    <element name="extension">
       <annotation>
          <appInfo>
-            <meta.element labelAttribute="name"/>
+            <meta.element labelAttribute="name" />
          </appInfo>
       </annotation>
       <complexType>
@@ -131,6 +138,9 @@
          </documentation>
       </annotation>
       <complexType>
+         <sequence>
+            <element ref="enablement" minOccurs="0" maxOccurs="1"/>
+         </sequence>
          <attribute name="icon" type="string">
             <annotation>
                <documentation>
@@ -204,7 +214,7 @@
          <meta.section type="copyright"/>
       </appInfo>
       <documentation>
-         Copyright (c) 2006, 2008 IBM Corporation and others.&lt;br&gt;
+         Copyright (c) 2006, 2011 IBM Corporation and others.&lt;br&gt;
 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 &lt;a href=&quot;http://www.eclipse.org/legal/epl-v10.html&quot;&gt;http://www.eclipse.org/legal/epl-v10.html&lt;/a&gt;
       </documentation>
    </annotation>
Index: ui/org/eclipse/jdt/internal/ui/javaeditor/SpecificContentAssistAction.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/SpecificContentAssistAction.java,v
retrieving revision 1.13
diff -u -r1.13 SpecificContentAssistAction.java
--- ui/org/eclipse/jdt/internal/ui/javaeditor/SpecificContentAssistAction.java	27 Apr 2011 07:48:35 -0000	1.13
+++ ui/org/eclipse/jdt/internal/ui/javaeditor/SpecificContentAssistAction.java	28 Dec 2011 15:27:58 -0000
@@ -7,6 +7,8 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Paul Fullbright <paul.fullbright@oracle.com> 
+ *     		- content assist category enablement (https://bugs.eclipse.org/bugs/show_bug.cgi?id=345213)
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.javaeditor;
 
@@ -29,6 +31,8 @@
 import org.eclipse.ui.texteditor.ITextEditor;
 import org.eclipse.ui.texteditor.IUpdate;
 
+import org.eclipse.jdt.core.IJavaProject;
+
 import org.eclipse.jdt.ui.text.IJavaPartitions;
 
 import org.eclipse.jdt.internal.ui.text.java.CompletionProposalCategory;
@@ -101,11 +105,15 @@
 	private boolean computeEnablement(ITextEditor editor) {
 		if (editor == null)
 			return false;
+		
 		ITextOperationTarget target= (ITextOperationTarget) editor.getAdapter(ITextOperationTarget.class);
-		boolean hasContentAssist= target != null && target.canDoOperation(ISourceViewer.CONTENTASSIST_PROPOSALS);
-		if (!hasContentAssist)
+		if (target == null || ! target.canDoOperation(ISourceViewer.CONTENTASSIST_PROPOSALS))
 			return false;
-
+		
+		IJavaProject javaProject = EditorUtility.getJavaProject(editor.getEditorInput());
+		if (! fCategory.matches(javaProject))
+			return false;
+		
 		ISelection selection= editor.getSelectionProvider().getSelection();
 		return isValidSelection(selection);
 	}
Index: ui/org/eclipse/jdt/internal/ui/text/java/CompletionProposalCategory.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/CompletionProposalCategory.java,v
retrieving revision 1.19
diff -u -r1.19 CompletionProposalCategory.java
--- ui/org/eclipse/jdt/internal/ui/text/java/CompletionProposalCategory.java	1 Mar 2011 11:50:36 -0000	1.19
+++ ui/org/eclipse/jdt/internal/ui/text/java/CompletionProposalCategory.java	28 Dec 2011 15:27:58 -0000
@@ -7,6 +7,8 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Paul Fullbright <paul.fullbright@oracle.com> 
+ *     		- content assist category enablement (https://bugs.eclipse.org/bugs/show_bug.cgi?id=345213)
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.text.java;
 
@@ -17,6 +19,12 @@
 
 import org.osgi.framework.Bundle;
 
+import org.eclipse.core.expressions.EvaluationContext;
+import org.eclipse.core.expressions.EvaluationResult;
+import org.eclipse.core.expressions.Expression;
+import org.eclipse.core.expressions.ExpressionConverter;
+import org.eclipse.core.expressions.ExpressionTagNames;
+
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.FileLocator;
 import org.eclipse.core.runtime.IConfigurationElement;
@@ -33,6 +41,8 @@
 import org.eclipse.jface.text.contentassist.ICompletionProposal;
 import org.eclipse.jface.text.contentassist.IContextInformation;
 
+import org.eclipse.jdt.core.IJavaProject;
+
 import org.eclipse.jdt.internal.corext.util.Messages;
 
 import org.eclipse.jdt.ui.text.java.ContentAssistInvocationContext;
@@ -54,6 +64,9 @@
 	private final IConfigurationElement fElement;
 	/** The image descriptor for this category, or <code>null</code> if none specified. */
 	private final ImageDescriptor fImage;
+	
+	/** The enablement expression for this category, or <code>null</code> if none specified. */
+	private final Expression fEnablementExpression;
 
 	private boolean fIsSeparateCommand= true;
 	private boolean fIsEnabled= true;
@@ -74,7 +87,16 @@
 			fName= fId;
 		else
 			fName= name;
-
+		
+		IConfigurationElement[] children= fElement.getChildren(ExpressionTagNames.ENABLEMENT);
+		if (children.length == 1) {
+			ExpressionConverter parser= ExpressionConverter.getDefault();
+			fEnablementExpression = parser.perform(children[0]);
+		}
+		else {
+			fEnablementExpression = null;
+		}
+		
 		String icon= element.getAttribute(ICON);
 		ImageDescriptor img= null;
 		if (icon != null) {
@@ -94,6 +116,7 @@
 		fId= id;
 		fName= name;
 		fElement= null;
+		fEnablementExpression = null;
 		fImage= null;
 	}
 
@@ -245,6 +268,35 @@
 	public void setSortOrder(int sortOrder) {
 		fSortOrder= sortOrder;
 	}
+	
+	/**
+	 * Determines if the project matches any enablement expression defined on the extension.
+	 * If there is no enablement expression, return true for any project.
+	 * Otherwise, if the project is null, return false.
+	 * 
+	 * @param javaProject - the project against which to test the enablement expression
+	 * @return true if this category is to be included in content proposals
+	 * @since 3.8
+	 */
+	public boolean matches(IJavaProject javaProject) {
+		if (fEnablementExpression == null) {
+			return true;
+		}
+		
+		if (javaProject == null) {
+			return false;
+		}
+		
+		try {
+			EvaluationContext evalContext= new EvaluationContext(null, javaProject);
+			evalContext.addVariable("project", javaProject); //$NON-NLS-1$
+			return fEnablementExpression.evaluate(evalContext) == EvaluationResult.TRUE;
+		} catch (CoreException e) {
+			JavaPlugin.log(e);
+		}
+		
+		return false;
+	}
 
 	/**
 	 * Safely computes completion proposals of all computers of this category through their
Index: ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java,v
retrieving revision 1.26
diff -u -r1.26 ContentAssistProcessor.java
--- ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java	1 Mar 2011 11:50:36 -0000	1.26
+++ ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java	28 Dec 2011 15:27:58 -0000
@@ -7,6 +7,8 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Paul Fullbright <paul.fullbright@oracle.com> 
+ *     		- content assist category enablement (https://bugs.eclipse.org/bugs/show_bug.cgi?id=345213)
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.text.java;
 
@@ -471,13 +473,24 @@
 		List<CompletionProposalCategory> included= new ArrayList<CompletionProposalCategory>();
 		for (Iterator<CompletionProposalCategory> it= fCategories.iterator(); it.hasNext();) {
 			CompletionProposalCategory category= it.next();
-			if (category.isIncluded() && category.hasComputers(fPartition))
+			if (checkDefaultEnablement(category)) 
 				included.add(category);
 		}
 		return included;
 	}
 
 	/**
+	 * Determine whether the category is enabled by default
+	 * 
+	 * @param category - the category to check
+	 * @return true if this category is enabled by default
+	 * @since 3.8
+	 */
+	protected boolean checkDefaultEnablement(CompletionProposalCategory category) {
+		return category.isIncluded() && category.hasComputers(fPartition);
+	}
+
+	/**
 	 * Informs the user about the fact that there are no enabled categories in the default content
 	 * assist set and shows a link to the preferences.
 	 *
@@ -565,12 +578,23 @@
 		ArrayList<CompletionProposalCategory> sorted= new ArrayList<CompletionProposalCategory>();
 		for (Iterator<CompletionProposalCategory> it= fCategories.iterator(); it.hasNext();) {
 			CompletionProposalCategory category= it.next();
-			if (category.isSeparateCommand() && category.hasComputers(fPartition))
+			if (checkSeparateEnablement(category))
 				sorted.add(category);
 		}
 		Collections.sort(sorted, ORDER_COMPARATOR);
 		return sorted;
 	}
+	
+	/**
+	 * Determine whether the category is enabled for separate use
+	 * 
+	 * @param category - the category to check
+	 * @return true if this category is enabled for separate use
+	 * @since 3.8
+	 */
+	protected boolean checkSeparateEnablement(CompletionProposalCategory category) {
+		return category.isSeparateCommand() && category.hasComputers(fPartition);
+	}
 
 	private String createEmptyMessage() {
 		return Messages.format(JavaTextMessages.ContentAssistProcessor_empty_message, new String[]{getCategoryLabel(fRepetition)});
Index: ui/org/eclipse/jdt/internal/ui/text/java/JavaCompletionProcessor.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/JavaCompletionProcessor.java,v
retrieving revision 1.82
diff -u -r1.82 JavaCompletionProcessor.java
--- ui/org/eclipse/jdt/internal/ui/text/java/JavaCompletionProcessor.java	1 Mar 2011 11:50:36 -0000	1.82
+++ ui/org/eclipse/jdt/internal/ui/text/java/JavaCompletionProcessor.java	28 Dec 2011 15:27:58 -0000
@@ -7,6 +7,8 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Paul Fullbright <paul.fullbright@oracle.com> 
+ *     		- content assist category enablement (https://bugs.eclipse.org/bugs/show_bug.cgi?id=345213)
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.text.java;
 
@@ -22,11 +24,14 @@
 
 import org.eclipse.ui.IEditorPart;
 
+import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.JavaCore;
 
 import org.eclipse.jdt.ui.text.java.ContentAssistInvocationContext;
 import org.eclipse.jdt.ui.text.java.JavaContentAssistInvocationContext;
 
+import org.eclipse.jdt.internal.ui.javaeditor.EditorUtility;
+
 /**
  * Java completion processor.
  */
@@ -83,6 +88,26 @@
 	}
 
 	/*
+	 * @see ContentAssistProcessor#checkDefaultEnablement(CompletionProposalCategory)
+	 */
+	@Override
+	protected boolean checkDefaultEnablement(CompletionProposalCategory category) {
+		return super.checkDefaultEnablement(category) && category.matches(getJavaProject());
+	}
+
+	/*
+	 * @see ContentAssistProcessor#checkSeparateEnablement(CompletionProposalCategory)
+	 */
+	@Override
+	protected boolean checkSeparateEnablement(CompletionProposalCategory category) {
+		return super.checkSeparateEnablement(category) && category.matches(getJavaProject());
+	}
+
+	private IJavaProject getJavaProject() {
+		return EditorUtility.getJavaProject(fEditor.getEditorInput());
+	}
+	
+	/*
 	 * @see org.eclipse.jdt.internal.ui.text.java.ContentAssistProcessor#filterAndSort(java.util.List, org.eclipse.core.runtime.IProgressMonitor)
 	 */
 	@Override