[JGIT PATCH v2 10/24] Added the iterface Rules.

@@ -0,0 +1,99 @@
+/*
+ *  Copyright (C) 2008 Florian Köberle
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public
+ *  License, version 2, as published by the Free Software Foundation.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
+ */
+package org.spearce.jgit.treewalk.rules;
+
+/**
+ * A {@link Rules} instances defines ignore or do not ignore rules for files in
+ * a directory. It can't directly be used to match files in sub directories, but
+ * provides a method {@link #getRulesForSubDirectory}.
+ * 
+ */
+public interface Rules {
+
+	/**
+	 * Provides the instance of {@link IgnoreAllRules}.
+	 */
+	public static final Rules IGNORE_ALL = new IgnoreAllRules();
+
+	/**
+	 * Provides the instance of {@link IgnoreNothingRules}.
+	 */
+	public static final Rules IGNORE_NOTHING = new IgnoreNothingRules();
+
+	/**
+	 * @param fileName
+	 *            the name of the file or directory.
+	 * @param fileIsDirectory
+	 *            should be true if the file is a directory.
+	 * @return true if the file or directory should be ignored.
+	 */
+	public abstract boolean toIgnore(String fileName, boolean fileIsDirectory);
+
+	/**
+	 * @param directoryName
+	 *            the sub directory for which you want an {@link Rules}
+	 *            instance.
+	 * @return an {@link Rules} instance, which can be used to check files in
+	 *         the specified sub directory.
+	 */
+	public abstract Rules getRulesForSubDirectory(String directoryName);
+
+	/**
+	 * This implementation ignores everything.
+	 */
+	public static final class IgnoreAllRules implements Rules {
+		private IgnoreAllRules() {
+			// declared to make the constructor private
+		}
+
+		public Rules getRulesForSubDirectory(String directoryName) {
+			return this;
+		}
+
+		public boolean toIgnore(String fileName, boolean fileIsDirectory) {
+			return true;
+		}
+
+		@Override
+		public String toString() {
+			return "ignore all rules";
+		}
+	}
+
+	/**
+	 * This implementation ignores nothing.
+	 */
+	public static final class IgnoreNothingRules implements Rules {
+		private IgnoreNothingRules() {
+			// declared to make the constructor private
+		}
+
+		public Rules getRulesForSubDirectory(String directoryName) {
+			return this;
+		}
+
+		public boolean toIgnore(String fileName, boolean fileIsDirectory) {
+			return false;
+		}
+
+		@Override
+		public String toString() {
+			return "ignore nothing rules";
+		}
+	}
+
+}