case-study/jdt-after/ui/org/eclipse/jdt/internal/ui/text/java/AbstractTemplateCompletionProposalComputer.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2011 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.jdt.internal.ui.text.java;
  12
  13 import java.util.ArrayList;
  14 import java.util.Arrays;
  15 import java.util.Collections;
  16 import java.util.List;
  17
  18 import org.eclipse.core.runtime.IProgressMonitor;
  19
  20 import org.eclipse.jface.text.contentassist.ICompletionProposal;
  21 import org.eclipse.jface.text.contentassist.IContextInformation;
  22
  23 import org.eclipse.jdt.core.ICompilationUnit;
  24
  25 import org.eclipse.jdt.ui.text.java.ContentAssistInvocationContext;
  26 import org.eclipse.jdt.ui.text.java.IJavaCompletionProposal;
  27 import org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer;
  28 import org.eclipse.jdt.ui.text.java.JavaContentAssistInvocationContext;
  29
  30 import org.eclipse.jdt.internal.ui.text.template.contentassist.TemplateEngine;
  31 import org.eclipse.jdt.internal.ui.text.template.contentassist.TemplateProposal;
  32
  33
  34 /**
  35  * An template completion proposal computer can generate template completion proposals
  36  * from a given TemplateEngine.
  37  *
  38  * Subclasses must implement {@link #computeCompletionEngine(JavaContentAssistInvocationContext)}
  39  *
  40  * @since 3.4
  41  */
  42 public abstract class AbstractTemplateCompletionProposalComputer implements IJavaCompletionProposalComputer {
  43
  44         /**
  45          * The engine for the current session, if any
  46          */
  47         private TemplateEngine fEngine;
  48
  49         /*
  50          * @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#computeCompletionProposals(org.eclipse.jface.text.contentassist.TextContentAssistInvocationContext, org.eclipse.core.runtime.IProgressMonitor)
  51          */
  52         public List<ICompletionProposal> computeCompletionProposals(ContentAssistInvocationContext context, IProgressMonitor monitor) {
  53                 if (!(context instanceof JavaContentAssistInvocationContext))
  54                         return Collections.emptyList();
  55
  56                 JavaContentAssistInvocationContext javaContext= (JavaContentAssistInvocationContext) context;
  57                 ICompilationUnit unit= javaContext.getCompilationUnit();
  58                 if (unit == null)
  59                         return Collections.emptyList();
  60
  61                 fEngine= computeCompletionEngine(javaContext);
  62                 if (fEngine == null)
  63                         return Collections.emptyList();
  64
  65                 fEngine.reset();
  66                 fEngine.complete(javaContext.getViewer(), javaContext.getInvocationOffset(), unit);
  67
  68                 TemplateProposal[] templateProposals= fEngine.getResults();
  69                 List<ICompletionProposal> result= new ArrayList<ICompletionProposal>(Arrays.asList(templateProposals));
  70
  71                 IJavaCompletionProposal[] keyWordResults= javaContext.getKeywordProposals();
  72                 if (keyWordResults.length == 0)
  73                         return result;
  74
  75                 /* Update relevance of template proposals that match with a keyword
  76                  * give those templates slightly more relevance than the keyword to
  77                  * sort them first.
  78                  */
  79                 for (int k= 0; k < templateProposals.length; k++) {
  80                         TemplateProposal curr= templateProposals[k];
  81                         curr.generated_5688875060909217458(keyWordResults);
  82                 }
  83                 return result;
  84         }
  85
  86         /**
  87          * Compute the engine used to retrieve completion proposals in the given context
  88          *
  89          * @param context the context where proposals will be made
  90          * @return the engine or <code>null</code> if no engine available in the context
  91          */
  92         protected abstract TemplateEngine computeCompletionEngine(JavaContentAssistInvocationContext context);
  93
  94         /*
  95          * @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#computeContextInformation(org.eclipse.jface.text.contentassist.TextContentAssistInvocationContext, org.eclipse.core.runtime.IProgressMonitor)
  96          */
  97         public List<IContextInformation> computeContextInformation(ContentAssistInvocationContext context, IProgressMonitor monitor) {
  98                 return Collections.emptyList();
  99         }
 100
 101         /*
 102          * @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#getErrorMessage()
 103          */
 104         public String getErrorMessage() {
 105                 return null;
 106         }
 107
 108         /*
 109          * @see org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer#sessionStarted()
 110          */
 111         public void sessionStarted() {
 112         }
 113
 114         /* (non-Javadoc)
 115          * @see org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer#sessionEnded()
 116          */
 117         public void sessionEnded() {
 118                 if (fEngine != null) {
 119                         fEngine.reset();
 120                         fEngine= null;
 121                 }
 122         }
 123
 124 }