From a93c80292d0474420654eb9cfa873ce20a6fbdc8 Mon Sep 17 00:00:00 2001
From: Sebastian Spaeth <Sebastian@SSpaeth.de>
Date: Tue, 8 Nov 2011 13:51:36 +0100
Subject: [PATCH] Curses UI: Simplify text buffer handling

Rather than keeping a separate queue of all logged lines in memory, we
rely on the curses window scrolling functionality to scroll lines. On
resizing the terminal this means, we'll clear the screen and start
filling it afresh, but that should be acceptable.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
---
 offlineimap/ui/Curses.py | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/offlineimap/ui/Curses.py b/offlineimap/ui/Curses.py
index 35a17fb..f1626c4 100644
--- a/offlineimap/ui/Curses.py
+++ b/offlineimap/ui/Curses.py
@@ -278,6 +278,7 @@ class InputHandler(ExitNotifyThread):
 
 
 class CursesLogHandler(logging.StreamHandler):
+    """self.ui has been set to the UI class before anything is invoked"""
 
     def emit(self, record):
         log_str = super(CursesLogHandler, self).format(record)
@@ -290,11 +291,9 @@ class CursesLogHandler(logging.StreamHandler):
         self.ui.tframe_lock.acquire()
         self.ui.lock()
         try:
-            for line in log_str.split("\n"):
-                self.ui.logwin.addstr("\n" + line, color)
-                self.ui.text.append((line, color))
-            while len(self.ui.text) > self.ui.logheight:
-                self.ui.text.popleft()
+            y,x = self.ui.logwin.getyx()
+            if y or x: self.ui.logwin.addch(10) # no \n before 1st item
+            self.ui.logwin.addstr(log_str, color)
         finally:
             self.ui.unlock()
             self.ui.tframe_lock.release()
@@ -360,7 +359,6 @@ class Blinkenlights(UIBase, CursesUtil):
         self.threadframes = {}
         self.accframes = {}
         self.aflock = Lock()
-        self.text = deque()
 
         self.stdscr = curses.initscr()
         # turn off automatic echoing of keys to the screen
@@ -543,7 +541,8 @@ class Blinkenlights(UIBase, CursesUtil):
     def setupwindows(self, resize=False):
         """Setup and draw bannerwin and logwin
 
-        If `resize`, don't create new windows, just adapt size"""
+        If `resize`, don't create new windows, just adapt size. This
+        function should be invoked with CursesUtils.locked()."""
         self.height, self.width = self.stdscr.getmaxyx()
         self.logheight = self.height - len(self.accframes) - 1
         if resize:
@@ -555,9 +554,8 @@ class Blinkenlights(UIBase, CursesUtil):
             self.logwin = curses.newwin(self.logheight, self.width, 1, 0)
 
         self.draw_bannerwin()
-        self.logwin.idlok(True) # needed for scrollok below
+        self.logwin.idlok(True)    # needed for scrollok below
         self.logwin.scrollok(True) # scroll window when too many lines added
-        self.logwin.move(self.logheight - 1, 0)
         self.draw_logwin()
         self.accounts = reversed(sorted(self.accframes.keys()))
         pos = self.height - 1
@@ -592,11 +590,9 @@ class Blinkenlights(UIBase, CursesUtil):
             color = curses.color_pair(0) #default colors
         else:
             color = curses.A_NORMAL
-        self.logwin.clear()
+        self.logwin.move(0, 0)
+        self.logwin.erase()
         self.logwin.bkgd(' ', color)
-        for line, color in self.text:
-            self.logwin.addstr("\n" + line, color)
-        self.logwin.noutrefresh()
 
     def getaccountframe(self, acc_name):
         """Return an AccountFrame() corresponding to acc_name