Only erase unwritten parts of screen

This avoids some unpleasant flickering when there's frequent updates.

2 files changed, 8 insertions, 3 deletions

diff --git a/ttystatus/area.py b/ttystatus/area.py
index c4e1aab..4e59fd8 100644
--- a/ttystatus/area.py
+++ b/ttystatus/area.py
@@ -51,6 +51,7 @@ class AreaManager(object):
         max_chars = self.get_max_line_length()
         up = self._terminal.get_up_sequence()
         down = self._terminal.get_down_sequence()
+        cr = self._terminal.get_carriage_return_sequence()
         erase = self._terminal.get_erase_line_sequence()
         lines = message.split('\n')
 
@@ -58,8 +59,9 @@ class AreaManager(object):
         for i, line in enumerate(message.split('\n')):
             if i > 0:
                 parts.append(down)
-            parts.append(erase)
+            parts.append(cr)
             parts.append(line[:max_chars])
+            parts.append(erase)
 
         self._terminal.write(''.join(parts))
 
diff --git a/ttystatus/tty.py b/ttystatus/tty.py
index db0962a..83561b6 100644
--- a/ttystatus/tty.py
+++ b/ttystatus/tty.py
@@ -57,10 +57,13 @@ class PhysicalTerminal(object):
         assert self._cud is not None
         return self._cud
 
-    def get_erase_line_sequence(self):
+    def get_carriage_return_sequence(self):
         assert self._cr is not None
+        return self._cr
+
+    def get_erase_line_sequence(self):
         assert self._el is not None
-        return self._cr + self._el
+        return self._el
 
     def get_size(self):
         '''Return width, height of terminal in characters, rows.