org.spearce.egit.ui/src/org/spearce/egit/ui/internal/components/RefContentProposal.java

   1 /*******************************************************************************
   2  * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
   3  *
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * See LICENSE for the full license text, also available.
   7  *******************************************************************************/
   8 package org.spearce.egit.ui.internal.components;
   9
  10 import java.io.IOException;
  11 import java.sql.Blob;
  12
  13 import org.eclipse.jface.fieldassist.IContentProposal;
  14 import org.spearce.egit.ui.Activator;
  15 import org.spearce.jgit.lib.Commit;
  16 import org.spearce.jgit.lib.Constants;
  17 import org.spearce.jgit.lib.ObjectId;
  18 import org.spearce.jgit.lib.PersonIdent;
  19 import org.spearce.jgit.lib.Ref;
  20 import org.spearce.jgit.lib.Repository;
  21 import org.spearce.jgit.lib.Tag;
  22 import org.spearce.jgit.lib.Tree;
  23
  24 /**
  25  * Content proposal class for refs names, specifically Ref objects - name with
  26  * optionally associated object id. This class can be used for Eclipse field
  27  * assist as content proposal.
  28  * <p>
  29  * Content of this proposal is simply a ref name, but description and labels
  30  * tries to be smarter - showing easier to read label for user (stripping
  31  * prefixes) and information about pointed object if it exists locally.
  32  */
  33 public class RefContentProposal implements IContentProposal {
  34         private static final String PREFIXES[] = new String[] { Constants.R_HEADS,
  35                         Constants.R_REMOTES, Constants.R_TAGS };
  36
  37         private static final String PREFIXES_DESCRIPTIONS[] = new String[] {
  38                         " [branch]", " [tracking branch]", " [tag]" };
  39
  40         private static void appendObjectSummary(final StringBuilder sb,
  41                         final String type, final PersonIdent author, final String message) {
  42                 sb.append(type + " by ");
  43                 sb.append(author.getName());
  44                 sb.append("\n");
  45                 sb.append(author.getWhen());
  46                 sb.append("\n\n");
  47                 final int newLine = message.indexOf('\n');
  48                 final int last = (newLine != -1 ? newLine : message.length());
  49                 sb.append(message.substring(0, last));
  50         }
  51
  52         private final Repository db;
  53
  54         private final String refName;
  55
  56         private final ObjectId objectId;
  57
  58         /**
  59          * Create content proposal for specified ref.
  60          *
  61          * @param repo
  62          *            repository for accessing information about objects. Could be a
  63          *            local repository even for remote objects.
  64          * @param ref
  65          *            ref being a content proposal. May have null or locally
  66          *            non-existent object id.
  67          */
  68         public RefContentProposal(final Repository repo, final Ref ref) {
  69                 this(repo, ref.getName(), ref.getObjectId());
  70         }
  71
  72         /**
  73          * Create content proposal for specified ref name and object id.
  74          *
  75          * @param repo
  76          *            repository for accessing information about objects. Could be a
  77          *            local repository even for remote objects.
  78          * @param refName
  79          *            ref name being a content proposal.
  80          * @param objectId
  81          *            object being pointed by this ref name. May be null or locally
  82          *            non-existent object.
  83          */
  84         public RefContentProposal(final Repository repo, final String refName,
  85                         final ObjectId objectId) {
  86                 this.db = repo;
  87                 this.refName = refName;
  88                 this.objectId = objectId;
  89         }
  90
  91         public String getContent() {
  92                 return refName;
  93         }
  94
  95         public int getCursorPosition() {
  96                 return refName.length();
  97         }
  98
  99         public String getDescription() {
 100                 if (objectId == null)
 101                         return null;
 102                 final Object obj;
 103                 try {
 104                         obj = db.mapObject(objectId, refName);
 105                 } catch (IOException e) {
 106                         Activator.logError("Unable to read object " + objectId
 107                                         + " for content proposal assistance", e);
 108                         return null;
 109                 }
 110
 111                 final StringBuilder sb = new StringBuilder();
 112                 sb.append(refName);
 113                 sb.append('\n');
 114                 sb.append(objectId.abbreviate(db).name());
 115                 sb.append(" - ");
 116                 if (obj instanceof Commit) {
 117                         final Commit c = ((Commit) obj);
 118                         appendObjectSummary(sb, "commit", c.getAuthor(), c.getMessage());
 119                 } else if (obj instanceof Tag) {
 120                         final Tag t = ((Tag) obj);
 121                         appendObjectSummary(sb, "tag", t.getAuthor(), t.getMessage());
 122                 } else if (obj instanceof Tree) {
 123                         sb.append("tree");
 124                 } else if (obj instanceof Blob) {
 125                         sb.append("blob");
 126                 } else
 127                         sb.append("locally unknown object");
 128                 return sb.toString();
 129         }
 130
 131         public String getLabel() {
 132                 for (int i = 0; i < PREFIXES.length; i++)
 133                         if (refName.startsWith(PREFIXES[i]))
 134                                 return refName.substring(PREFIXES[i].length())
 135                                                 + PREFIXES_DESCRIPTIONS[i];
 136                 return refName;
 137
 138         }
 139 }