X-Git-Url: http://git.argeo.org/?a=blobdiff_plain;ds=sidebyside;f=org.argeo.slc.client.ui.dist%2Fsrc%2Forg%2Fargeo%2Fslc%2Fclient%2Fui%2Fdist%2Futils%2FVersionComparator.java;fp=org.argeo.slc.client.ui.dist%2Fsrc%2Forg%2Fargeo%2Fslc%2Fclient%2Fui%2Fdist%2Futils%2FVersionComparator.java;h=4492b06694f81ef3042a07aeb12afffe93949e49;hb=2db415932b071525adb52c6374e021174512a924;hp=0000000000000000000000000000000000000000;hpb=7e2f6c6ae08e97925955184aaa29035ac05de149;p=gpl%2Fargeo-slc.git

diff --git a/org.argeo.slc.client.ui.dist/src/org/argeo/slc/client/ui/dist/utils/VersionComparator.java b/org.argeo.slc.client.ui.dist/src/org/argeo/slc/client/ui/dist/utils/VersionComparator.java
new file mode 100644
index 000000000..4492b0669
--- /dev/null
+++ b/org.argeo.slc.client.ui.dist/src/org/argeo/slc/client/ui/dist/utils/VersionComparator.java
@@ -0,0 +1,68 @@
+package org.argeo.slc.client.ui.dist.utils;
+
+import org.eclipse.jface.viewers.Viewer;
+import org.eclipse.jface.viewers.ViewerComparator;
+
+/**
+ * Enable comparison of two version string with form "1.2.5.qualifier" with
+ * following rules and assumptions:
+ * <ul>
+ * <li>
+ * Version are parsed and compared segment by segment; doing best effort to
+ * convert major, minor and micro to integer and compare them as such (to have
+ * 0.1 < 0.9 < 0.10 not 0.1 < 0.10 < 0.9).</li>
+ * <li>Version should not contain any dash (-), version segments should be
+ * separated by dots (.)</li>
+ * </ul>
+ */
+
+public class VersionComparator extends ViewerComparator {
+
+	@Override
+	public int compare(Viewer viewer, Object e1, Object e2) {
+		String s1 = (String) e1;
+		String s2 = (String) e2;
+		return compareVersion(s1, s2);
+	}
+
+	/**
+	 * Enable comparison of two versions of the form
+	 * "major.minor.micro.qualifier". We assume the separator is always a "."
+	 * and make best effort to convert major, minor and micro to int.
+	 */
+	private int compareVersion(String v1, String v2) {
+		String[] t1 = v1.split("\\.");
+		String[] t2 = v2.split("\\.");
+
+		for (int i = 0; i < t1.length && i < t2.length; i++) {
+			int result = compareToken(t1[i], t2[i]);
+			if (result != 0)
+				return result;
+		}
+		if (t1.length > t2.length)
+			return 1;
+		else if (t1.length < t2.length)
+			return -1;
+		else
+			return 0;
+	}
+
+	private int compareToken(String t1, String t2) {
+		if (t1 == null && t2 == null)
+			return 0;
+		else if (t1 == null)
+			return -1;
+		else if (t2 == null)
+			return 1;
+
+		Integer i1 = null, i2 = null;
+		try {
+			i1 = new Integer(t1);
+			i2 = new Integer(t2);
+		} catch (NumberFormatException nfe) {
+			// the format is not valid we silently compare as String
+			return t1.compareTo(t2);
+		}
+		return i1.compareTo(i2);
+	}
+}
\ No newline at end of file