fix(TTk): register resize event callbacks on init to avoid exception

Allows mainloop() to be started from a different thread without encountering exception "signal only works in main thread of the main interpreter" on start. This makes sense because window resizing events come from the host.

Author: slook

libs/pyTermTk/TermTk/TTkCore/drivers/term_unix_common.py

@@ -125,6 +125,7 @@ def _sigWinCh(signum, frame):
     def _registerResizeCb(callback):
         _TTkTerm._sigWinChCb = callback
         # Dummy call to retrieve the terminal size
+        # signal only works in main thread of the main interpreter
         _TTkTerm._sigWinCh(signal.SIGWINCH, None)
         signal.signal(signal.SIGWINCH, _TTkTerm._sigWinCh)
     TTkTermBase.registerResizeCb = _registerResizeCb

libs/pyTermTk/TermTk/TTkCore/ttk.py

@@ -106,11 +106,15 @@ def __init__(self, *,
         self._mouseCursor = None
         self._showMouseCursor = os.environ.get("TERMTK_MOUSE",mouseCursor)
         super().__init__(**kwargs)
+
+        # Register system event signals from main_thread
         TTkInput.inputEvent.connect(self._processInput)
         TTkInput.pasteEvent.connect(self._processPaste)
         TTkSignalDriver.sigStop.connect(self._SIGSTOP)
         TTkSignalDriver.sigCont.connect(self._SIGCONT)
         TTkSignalDriver.sigInt.connect( self._SIGINT)
+        TTkSignalDriver.init()
+
         self._drawMutex = threading.Lock()
         self._paintEvent = threading.Event()
         self._paintEvent.set()
@@ -127,6 +131,7 @@ def __init__(self, *,
             self._showMouseCursor = True
 
         TTkHelper.registerRootWidget(self)
+        TTkTerm.registerResizeCb(self._win_resize_cb)
 
     frame = 0
     time = time.time()
@@ -140,12 +145,12 @@ def _fps(self):
             self.time  = curtime
 
     def mainloop(self):
+        '''Enters the main event loop and waits until :meth:`~quit` is called or the main widget is destroyed.'''
         with ttk_capture_stderr():
             self._mainloop_1()
 
     def _mainloop_1(self):
         try:
-            '''Enters the main event loop and waits until :meth:`~quit` is called or the main widget is destroyed.'''
             TTkLog.debug( "" )
             TTkLog.debug( "         ████████╗            ████████╗    " )
             TTkLog.debug( "         ╚══██╔══╝            ╚══██╔══╝    " )
@@ -160,13 +165,6 @@ def _mainloop_1(self):
             TTkLog.debug( "Starting Main Loop..." )
             TTkLog.debug(f"screen = ({TTkTerm.getTerminalSize()})")
 
-            # Register events
-            TTkSignalDriver.init()
-
-            TTkLog.debug("Signal Event Registered")
-
-            TTkTerm.registerResizeCb(self._win_resize_cb)
-
             self._timer = TTkTimer()
             self._timer.timeout.connect(self._time_event)
             self._timer.start(0.1)