lemonbar: Screen working somewhat. Remove one fifo

.i3/lemonbar/i3_lemonbar_common.py

@@ -1,4 +1,4 @@
-import subprocess
+import subprocess, os, getpass
 from enum import Enum
 
 import i3_lemonbar_config as config
@@ -9,6 +9,9 @@ kill_on_unfocus = []
 logger = None
 health_logger = None
 
+screen = None
+parsing_queue = None
+
 class bar_mode(Enum):
     power, normal, control = range(-1,2) # Don't cycle through power
 
@@ -20,9 +23,6 @@ class bar_mode(Enum):
 
 mode = bar_mode.normal
 
-screen_args = ['screen', '-d', '-m', '-U', '-S', 'lemonbar'
-                , '-L', '-Logfile', config.fifo_screen_log]
-
 floatterm_args = lambda prog : ['terminator', '-r', 'FLOAT_TERM', '-p'
         , 'dark', '-e', 'echo kill_unfocus $$ > {}; exec {}'.format(
             config.fifo_file_executor, prog)]
@@ -66,16 +66,13 @@ def bluetooth(args):
     btcargs = args.split()[1:]
     btcargs = [a.replace('pxc550', '00:16:94:22:29:0E') for a in btcargs]
     inp = ' '.join(btcargs)
-    stuff_screen(inp)
+    screen.send_cmd('bluetoothctl ' + inp)
 
 show_secs = False
 def toggle_secs(args):
     global show_secs
     show_secs = not show_secs
 
-def stuff_screen(cmd):
-    subprocess.run(['screen', '-S', 'lemonbar', '-X', 'stuff', "echo " + cmd + "\\n"])
-
 # Keymaps
 def_keymap = 'pl'
 keymaps = {'Firefox': 'se'}
@@ -154,3 +151,49 @@ def set_keymap(i3ws):
         new_km = def_keymap
         logger.debug('Setting default keymap {} for {}'.format(def_keymap, wclass))
     subprocess.call(['/home/kuba/.i3/scripts/lang.sh', 'qset', new_km])
+
+def create_new_fifo(fifo_file):
+    """
+    Create new fifo file, removing old one if it exists
+    """
+    try:
+        os.remove(fifo_file)
+        logger.debug('''Removed old fifo file''')
+    except OSError:
+        logger.debug('''No old fifo file, good''')
+
+    try:
+        os.mkfifo(fifo_file)
+    except OSError:
+        logger.error('''Failed, couldn't create fifo file''')
+        os.remove(config.pid_file) # Clean up own PID file
+        sys.exit(0)
+
+class LemonbarScreen:
+    # Start, stop and send commands to screen instance
+
+    # Start detached, in UTF-8 mode. Log to fifo
+    start_flags = ['-d', '-m', '-U', '-L', '-Logfile', config.fifo_screen_log]
+
+    def __init__(self):
+        self.identifier = 'lemonbar_{}_{}'.format(getpass.getuser(), os.getpid())
+
+        create_new_fifo(config.fifo_screen_log)
+        self.send(self.start_flags)          # Start screen
+        self.send_cmd('stty -echo')          # Do not echo what is written to screen terminal
+        self.send_colon('logfile flush 0.1') # Log quickly
+
+    def destroy(self):
+        self.send_colon('kill')
+
+    def send(self, args):
+        # Send something to our screen instance
+        subprocess.call(['screen', '-S', self.identifier] + args)
+
+    def send_cmd(self, cmd):
+        # Send terminal input to our screen instance
+        self.send(['-X', 'stuff', cmd + '\n'])
+
+    def send_colon(self, cmd):
+        # Send colon command to our screen instance
+        self.send(['-X', 'colon', cmd + '\n'])