Added launch_at_startup_supported_engines to info.yml to remove hard-…

…coded SUPPORTED_ENGINES list from app.

app.py

@@ -90,18 +90,17 @@ def init_app(self):
 
             if self.get_setting("launch_at_startup"):
                 # show the file manager UI
-                if self.engine.name in SUPPORTED_ENGINES:
-                    # use a single-shot timer to show the open dialog to allow everything to
-                    # finish being set up first:
-                    from sgtk.platform.qt import QtCore
-
-                    QtCore.QTimer.singleShot(200, self.show_file_open_dlg)
-                else:
+                if SUPPORTED_ENGINES and self.engine.name not in SUPPORTED_ENGINES:
                     self.log_warning(
                         "Sorry, the launch at startup option is currently not supported "
                         "in this engine! You can currently only use it with the following "
                         "engines: %s" % ", ".join(SUPPORTED_ENGINES)
                     )
+                else:  # use a single-shot timer to show the open dialog to allow everything to
+                    # finish being set up first:
+                    from sgtk.platform.qt import QtCore
+
+                    QtCore.QTimer.singleShot(200, self.show_file_open_dlg)
 
     def destroy_app(self):
         """

info.yml

@@ -255,6 +255,10 @@ requires_engine_version:
 # the engines that this app can operate in:
 supported_engines:
 
+# the engines that can launch this app on startup
+# currently, we have done QA on the following engines:
+launch_at_startup_supported_engines: [tk-nuke, tk-maya, tk-3dsmax, tk-katana, tk-katana_foundry]  # remove tk-katana_foundry when merged with official release
+
 # the frameworks required to run this app
 frameworks:
     # We need a version of tk-framework-shotgunutils with a fix for deleting items.