[cuegui] Add exit handler to save state (AcademySoftwareFoundation#1489)

When the application is closed or killed, an exit_handler is triggered
to save the state on a qt settings file.

cuegui/cuegui/Main.py

@@ -24,6 +24,7 @@
 import signal
 
 from qtpy import QtGui
+from qtpy import QtCore
 
 import cuegui
 import cuegui.Layout
@@ -81,6 +82,14 @@ def startup(app_name, app_version, argv):
     mainWindow.displayStartupNotice()
     mainWindow.show()
 
+    # Allow ctrl-c to kill the application
+    signal.signal(signal.SIGINT, mainWindow.handleExit)
+    signal.signal(signal.SIGTERM, mainWindow.handleExit)
+
+    # Custom qt message handler to ignore known warnings
+    QtCore.qInstallMessageHandler(warning_handler)
+
+
     # Open all windows that were open when the app was last closed
     for name in mainWindow.windows_names[1:]:
         if settings.value("%s/Open" % name, "false").lower() == 'true':
@@ -112,6 +121,22 @@ def __setup_sentry():
     except ImportError:
         logger.warning('Failed to import Sentry')
 
+
+def warning_handler(msg_type, msg_log_context, msg_string):
+    """
+    Handler qt warnings. Ignore known warning messages that happens when
+    multi-threaded/multiple updates happen in a short span
+    """
+    if ('QTextCursor::setPosition:' in msg_string or
+        'SelectionRequest too old' in msg_string):
+        return
+
+    logger.warning('%s: %s, Message: %s',
+                   str(msg_type),
+                   str(msg_log_context),
+                   str(msg_string))
+
+
 def closingTime():
     """Window close callback."""
     logger.info("Closing all threads...")

cuegui/cuegui/MainWindow.py

@@ -119,6 +119,13 @@ def displayAbout(self):
         msg += "Python:\n%s\n\n" % sys.version
         QtWidgets.QMessageBox.about(self, "About", msg)
 
+    def handleExit(self, sig, flag):
+        """Save current state and close the application"""
+        del sig
+        del flag
+        self.__saveSettings()
+        self.__windowCloseApplication()
+
     @staticmethod
     def openSuggestionPage():
         """Opens the suggestion page URL."""
@@ -364,9 +371,6 @@ def __windowOpened(self):
     def __windowClosed(self):
         """Called from closeEvent on window close"""
 
-        # Disconnect to avoid multiple attempts to close a window
-        self.app.quit.connect(self.close)
-
         # Save the fact that this window is open or not when the app closed
         self.settings.setValue("%s/Open" % self.name, self.app.closingApp)
 
@@ -386,6 +390,8 @@ def __windowCloseApplication(self):
         to exit."""
         self.app.closingApp = True
         self.app.quit.emit()
+        # Give the application some time to save the state
+        time.sleep(4)
 
     ################################################################################
 

cuegui/cuegui/plugins/LogViewPlugin.py

@@ -514,6 +514,7 @@ def __init__(self, parent=None):
 
         self.SIG_CONTENT_UPDATED.connect(self._update_log_content)
         self.log_thread_pool = QtCore.QThreadPool()
+        self.log_thread_pool.waitForDone()
 
     def _on_mouse_pressed(self, pos):
         """