Windows: Detect system shutdown and don't restart daemon throught it …

…(Ref #83)

syncthing_gtk/app.py

@@ -106,6 +106,9 @@ def __init__(self, gladepath="/usr/share/syncthing-gtk",
 		self.devices_never_loaded = True
 		self.folders_never_loaded = True
 		self.sync_animation = 0
+		if IS_WINDOWS:
+			import syncthing_gtk.windows
+			self.shutdown_detector = windows.detect_shutdown()
 
 	def do_startup(self, *a):
 		Gtk.Application.do_startup(self, *a)
@@ -362,9 +365,12 @@ def start_daemon_ui(self):
 		self.display_connect_dialog(_("Starting Syncthing daemon"))
 		# Start daemon
 		self.start_daemon()
-
+	
 	def start_daemon(self):
 		if self.process is None:
+			if IS_WINDOWS and self.shutdown_detector.shuting_down:
+				log.warning("Not starting daemon: System shutdown detected")
+				return
 			self.process = DaemonProcess([self.config["syncthing_binary"], "-no-browser"])
 			self.process.connect('failed', self.cb_daemon_startup_failed)
 			self.process.connect('exit', self.cb_daemon_exit)
@@ -1747,10 +1753,8 @@ def cb_daemon_exit(self, proc, error_code):
 				# New daemon version is downloaded and ready to use.
 				# Switch to this version before restarting
 				self.swap_updated_binary()
-			self.process = DaemonProcess([self.config["syncthing_binary"], "-no-browser"])
-			self.process.connect('failed', self.cb_daemon_startup_failed)
-			self.process.connect('exit', self.cb_daemon_exit)
-			self.process.start()
+			self.process = None
+			self.start_daemon()
 
 	def cb_daemon_startup_failed(self, proc, exception):
 		"""

syncthing_gtk/windows.py

@@ -9,7 +9,8 @@
 from __future__ import unicode_literals
 from syncthing_gtk.tools import IS_WINDOWS
 from gi.repository import Gio, GLib, GObject
-import os, logging, codecs, msvcrt, win32pipe, _winreg
+import os, logging, codecs, msvcrt, win32pipe
+import win32gui, win32api, win32con, _winreg
 log = logging.getLogger("windows.py")
 
 def fix_localized_system_error_messages():
@@ -38,6 +39,45 @@ def dont_use_localization_in_gtk():
 	"""
 	os.environ['LANGUAGE'] = 'en_US'
 
+def detect_shutdown():
+	"""
+	Returns ShutdownDetector object. If system shutdown is detected,
+	shuting_down property of returned object will be set to True.
+	"""
+	return ShutdownDetector()
+
+class ShutdownDetector:
+	"""
+	Creates dummy, invisible win32 window and listens for windows
+	messages on it (using GLib.idle_add). If WM_ENDSESSION message
+	is recieved, set's own shuting_down property to True
+	"""
+	def __init__(self):
+		self.shuting_down = False
+		hinst = win32api.GetModuleHandle(None)
+		wndclass = win32gui.WNDCLASS()
+		wndclass.hInstance = hinst
+		wndclass.lpszClassName = str("STGTKDummyWindowClass")
+		messageMap = { win32con.WM_ENDSESSION : self._proc }
+
+		wndclass.lpfnWndProc = messageMap
+		wc = win32gui.RegisterClass(wndclass)
+		self.hwnd = win32gui.CreateWindowEx(win32con.WS_EX_LEFT,
+				wc, "STGTKDummyWindowClass", 0, 0, 0, 
+				win32con.CW_USEDEFAULT, win32con.CW_USEDEFAULT,
+				0, 0, hinst, None)
+
+		GLib.timeout_add_seconds(1, self._pump)
+
+	def _pump(self):
+		win32gui.PumpWaitingMessages()
+		return True
+
+	def _proc(self, hwnd, msg, wparam, lparam):
+		if msg == win32con.WM_ENDSESSION:
+			log.warning("System shutdown detected")
+			self.shuting_down = True
+
 class WinPopenReader:
 	"""
 	Reads from PIPE using GLib timers or idle_add. Emulates part of