Add command line support for "git difftool"

see: http://git-scm.com/docs/git-difftool

* add command line support for "jgit difftool"
* show supported commands with "jgit difftool --help"
* added "git difftool --tool-help" to show the tools (empty now)
* prepare for all other commands

Bug: 356832
Change-Id: Ice0c13ef7953a20feaf25e7746d62b94ff4e89e5
Signed-off-by: Andre Bossert <andre.bossert@siemens.com>
Signed-off-by: Simeon Andreev <simeon.danailov.andreev@gmail.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/diffmergetool/ExternalDiffTool.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/diffmergetool/ExternalDiffTool.java
new file mode 100644
index 0000000000..f2d7e828cb
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/diffmergetool/ExternalDiffTool.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2018-2021, Andre Bossert <andre.bossert@siemens.com>
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+package org.eclipse.jgit.internal.diffmergetool;
+
+/**
+ * The external tool interface.
+ */
+public interface ExternalDiffTool {
+
+	/**
+	 * @return the tool name
+	 */
+	String getName();
+
+	/**
+	 * @return the tool path
+	 */
+	String getPath();
+
+	/**
+	 * @return the tool command
+	 */
+	String getCommand();
+
+}