From 4a847a9870e0eebb5efff3012e4eaaf5974735f1 Mon Sep 17 00:00:00 2001
From: Nikos Skalkotos <skalkoto@grnet.gr>
Date: Wed, 8 Aug 2012 16:13:57 +0300
Subject: [PATCH] Add a new clear method in the Output class

In the cli output classes this method will clear terminal screen if
the standard output is a terminal.
---
 image_creator/dialog_wizard.py   |    2 +-
 image_creator/output/__init__.py |    3 +++
 image_creator/output/cli.py      |    9 +++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/image_creator/dialog_wizard.py b/image_creator/dialog_wizard.py
index 8e122a8..e26975e 100644
--- a/image_creator/dialog_wizard.py
+++ b/image_creator/dialog_wizard.py
@@ -177,7 +177,7 @@ def extract_image(session):
     device.out = out
     image_os.out = out
 
-    out.output()
+    out.clear()
 
     #Sysprep
     device.mount(False)
diff --git a/image_creator/output/__init__.py b/image_creator/output/__init__.py
index 99653d3..3992846 100644
--- a/image_creator/output/__init__.py
+++ b/image_creator/output/__init__.py
@@ -48,6 +48,9 @@ class Output(object):
     def cleanup(self):
         pass
 
+    def clear(self):
+        pass
+
     def _get_progress(self):
         progress = self._Progress
         progress.output = self
diff --git a/image_creator/output/cli.py b/image_creator/output/cli.py
index c7b5a55..37022d5 100644
--- a/image_creator/output/cli.py
+++ b/image_creator/output/cli.py
@@ -58,6 +58,12 @@ def success(msg, new_line=True, colored=True):
     output(msg, new_line, color)
 
 
+def clear():
+    #clear the page
+    if sys.stderr.isatty():
+        sys.stderr.write('\033[H\033[2J')
+
+
 class SilentOutput(Output):
     pass
 
@@ -78,6 +84,9 @@ class SimpleOutput(Output):
     def output(self, msg='', new_line=True):
         output(msg, new_line)
 
+    def clear(self):
+        clear()
+
 
 class OutputWthProgress(SimpleOutput):
     class _Progress(Bar):
-- 
1.7.10.4