Make init_window_content compatible with the way async calls work in GTK

though the async call itself is commented. Related to #377

src/main.py

@@ -111,11 +111,11 @@ def open_window_with_content(self, gfile, get_cb):
 		clipboard content."""
 		win = DrWindow(application=self)
 		win.present()
-		win.init_window_content(gfile, get_cb) # this optimization has no effect
-		# because of GLib unknown magic, but should be kept anyway because the
-		# window is presented to the user regardless of loading errors, making
-		# any issue in `init_window_content` very explicit, and more likely to
-		# be reported.
+
+		content_params = {'gfile': gfile, 'get_cb': get_cb}
+		# Parameters are: time in milliseconds, method, data # XXX todo?
+		# GLib.timeout_add(10, win.init_window_content_async, content_params)
+		win.init_window_content_async(content_params)
 		return win
 
 	def on_activate(self, *args):

src/window.py

@@ -113,13 +113,22 @@ def __init__(self, **kwargs):
 		# self.resize(720, 288)
 		self._set_ui_bars()
 
-	def init_window_content(self, gfile, get_cb):
+	def init_window_content_async(self, content_params):
 		"""Initialize the window's content, such as the minimap, the color
 		popovers, the tools, their options, and a new image. Depending on the
 		parameters, the new image can be imported from the clipboard, loaded
-		from a GioFile, or (else) it can be a blank image."""
+		from a GioFile, or (else) it can be a blank image.
+
+		This method is called asynchronously, which isn't *correct* (not very
+		thread-safe or anything) but it allows the window to be shown quicker.
+		If it fails, a window is here anyway because this is independant from
+		the object constructor."""
+
 		self.prompt_action(_("Error starting the application, please report this bug."))
 
+		gfile = content_params['gfile']
+		get_cb = content_params['get_cb']
+
 		self.tools = {}
 		self.minimap = DrMinimap(self, None)
 		self.options_manager = DrOptionsManager(self)
@@ -148,6 +157,9 @@ def init_window_content(self, gfile, get_cb):
 		self.set_picture_title()
 		self._try_show_release_notes()
 
+		# has to return False to be removed from the mainloop immediatly
+		return False
+
 	def _try_show_release_notes(self):
 		last_version = self.gsettings.get_string('last-version')
 		current_version = self.app.get_current_version()