Keep ioctl to VT when correcting OpenRoberta#72

roberta/lab.py

@@ -154,29 +154,41 @@ def status(self, status):
 class GfxMode(object):
 
     def __init__(self):
+        self.tty_name = os.ttyname(sys.stdin.fileno())
+        # get digit from string
+        self.tty_num = int(list(filter(str.isdigit, self.tty_name))[0])
+        # TODO: get tty number from calling program as parameter
         self.previous_tty_num = 3
-        self.previous_tty_name = "/dev/tty" + str(self.previous_tty_num)
-        self.tty_num = 5
-        self.tty_name = "/dev/tty" + str(self.tty_num)
+        self.previous_tty_name = '/dev/tty' + str(self.previous_tty_num)
         try:
-            self.bus = dbus.SystemBus()
-            self.devobj = self.bus.get_object('org.freedesktop.login1', '/org/freedesktop/login1/seat/seat0')
-            self.devprop = dbus.Interface(self.devobj, "org.freedesktop.DBus.Properties")
-            self.dev = dbus.Interface(self.devobj, 'org.freedesktop.login1.Seat')
+            bus = dbus.SystemBus()
+            seat_obj = bus.get_object('org.freedesktop.login1', '/org/freedesktop/login1/seat/seat0')
+            seat_props = dbus.Interface(seat_obj, 'org.freedesktop.DBus.Properties')
+            self.seat_methods = dbus.Interface(seat_obj, 'org.freedesktop.login1.Seat')
         except:
             logger.exception('cannot open dbus interface for org.freedesktop.login1.Seat')
 
     def __enter__(self):
+        logger.info('running on tty: %s', self.tty_name)
+        # really useful ? Can block if permission is not set correctly on /dev/ttyx
+        with open(self.tty_name, 'r') as tty:
+            # KDSETMODE = 0x4B3A, GRAPHICS = 0x01
+            ioctl(tty, 0x4B3A, 0x01)
         try:
-            self.dev.SwitchTo(self.tty_num)
-            logger.info('running on tty: %s', self.tty_name)
+            self.seat_methods.SwitchTo(self.tty_num)
         except:
             logger.exception('cannot switch to: %s', self.tty_name)
 
     def __exit__(self, type, value, traceback):
+        logger.info('switching back to tty: %s', self.previous_tty_name)
+        # really useful ? Can block if permission is not set correctly on /dev/ttyx
+        with open(self.tty_name, 'w') as tty:
+            # KDSETMODE = 0x4B3A, TEXT = 0x00
+            ioctl(tty, 0x4B3A, 0x00)
+            # send Ctrl-L to tty to clear
+            tty.write('\033c')
         try:
-            self.dev.SwitchTo(self.previous_tty_num)
-            logger.info('running on tty: %s', self.previous_tty_name)
+            self.seat_methods.SwitchTo(self.previous_tty_num)
         except:
             logger.exception('cannot switch back to: %s', self.previous_tty_name)