plugins/org.argeo.slc.client.ui.dist/src/main/java/org/argeo/slc/client/ui/dist/utils/NameVersionComparator.java

   1 package org.argeo.slc.client.ui.dist.utils;
   2
   3 import org.argeo.eclipse.ui.TreeParent;
   4 import org.eclipse.jface.viewers.Viewer;
   5 import org.eclipse.jface.viewers.ViewerComparator;
   6
   7 /**
   8  * Enable comparison of two names version string with form org.argeo.slc-1.2.x.
   9  * with following rules and assumptions:
  10  * <ul>
  11  * <li>
  12  * Names are ordered using Lexicographical order</li>
  13  * <li>
  14  * Version are parsed and compared segment by segment; doing best effort to
  15  * convert major, minor and micro to integer and compare them as such (to have
  16  * 0.1 < 0.9 < 0.10 not 0.1 < 0.10 < 0.9).</li>
  17  * <li>Version should not contain any dash (-), version segments should be
  18  * separated by dots (.)</li>
  19  * </ul>
  20  */
  21
  22 public class NameVersionComparator extends ViewerComparator {
  23
  24         private VersionComparator vc = new VersionComparator();
  25
  26         @Override
  27         public int category(Object element) {
  28                 if (element instanceof String) {
  29                         int lastInd = ((String) element).lastIndexOf('-');
  30                         if (lastInd > 0)
  31                                 return 10;
  32                 }
  33                 // unvalid names always last
  34                 return 5;
  35         }
  36
  37         @Override
  38         public int compare(Viewer viewer, Object e1, Object e2) {
  39                 int cat1 = category(e1);
  40                 int cat2 = category(e2);
  41
  42                 if (cat1 != cat2) {
  43                         return cat1 - cat2;
  44                 }
  45
  46                 int result = 0;
  47
  48                 String s1, s2;
  49
  50                 if (e1 instanceof TreeParent) {
  51                         s1 = ((TreeParent) e1).getName();
  52                         s2 = ((TreeParent) e2).getName();
  53                 } else {
  54                         s1 = e1.toString();
  55                         s2 = e2.toString();
  56                 }
  57
  58                 int i1 = s1.lastIndexOf('-');
  59                 int i2 = s2.lastIndexOf('-');
  60
  61                 // Specific cases, unvalid Strings
  62                 if (i1 < 0)
  63                         if (i2 < 0)
  64                                 return s1.compareTo(s2);
  65                         else
  66                                 return 1;
  67                 else if (i2 < 0)
  68                         return -1;
  69
  70                 String aName = s1.substring(0, s1.lastIndexOf('-'));
  71                 String aVersion = s1.substring(s1.lastIndexOf('-'));
  72
  73                 String bName = s2.substring(0, s2.lastIndexOf('-'));
  74                 String bVersion = s2.substring(s2.lastIndexOf('-'));
  75
  76                 result = aName.compareTo(bName);
  77                 if (result != 0)
  78                         return result;
  79                 else
  80                         return vc.compare(viewer, aVersion, bVersion);
  81         }
  82 }