[Console] Cleanup terminal resize handler

Improve readability

Move imports available on Windows out of try..except.

For future reference in Python 3.11 termios now has window size methods
but the added complexity of handling older Python versions is not worth
it.

https://docs.python.org/3/library/termios.html#termios.tcgetwinsize

deluge/ui/console/main.py

@@ -253,8 +253,8 @@ deluge-console.exe "add -p c:\\mytorrents c:\\new.torrent"
         reactor.run()
 
     @overrides(TermResizeHandler)
-    def on_terminal_size(self, *args):
-        rows, cols = super().on_terminal_size(args)
+    def on_resize(self, *args):
+        rows, cols = super().on_resize(*args)
         for mode in self.modes:
             self.modes[mode].on_resize(rows, cols)
 

deluge/ui/console/modes/basemode.py

@@ -8,7 +8,10 @@
 #
 
 import logging
+import signal
+import struct
 import sys
+from typing import Tuple
 
 import deluge.component as component
 import deluge.ui.console.utils.colors as colors
@@ -22,10 +25,8 @@ except ImportError:
     pass
 
 try:
-    import signal
-    import struct
-    import termios
     from fcntl import ioctl
+    from termios import TIOCGWINSZ
 except ImportError:
     pass
 
@@ -62,17 +63,20 @@ class InputKeyHandler:
 class TermResizeHandler:
     def __init__(self):
         try:
-            signal.signal(signal.SIGWINCH, self.on_terminal_size)
+            signal.signal(signal.SIGWINCH, self.on_resize)
         except ValueError as ex:
             log.debug('TermResize unavailable, unable to catch SIGWINCH signal: %s', ex)
         except AttributeError as ex:
             log.debug('TermResize unavailable, no SIGWINCH signal on Windows: %s', ex)
 
-    def on_terminal_size(self, *args):
-        # Get the new rows and cols value
-        rows, cols = struct.unpack('hhhh', ioctl(0, termios.TIOCGWINSZ, b'\000' * 8))[
-            0:2
-        ]
+    @staticmethod
+    def get_window_size(fd: int = 0) -> Tuple[int, int]:
+        """Return the tty window size as row, col."""
+        return struct.unpack('4h', ioctl(fd, TIOCGWINSZ, b'\x00' * 8))[0:2]
+
+    def on_resize(self, _signum, _frame):
+        """Handler for SIGWINCH when terminal changes size"""
+        rows, cols = self.get_window_size()
         curses.resizeterm(rows, cols)
         return rows, cols