fix(linux): display error and abort if fonttools are missing

linux/keyman-config/keyman_config/__init__.py

@@ -1,5 +1,6 @@
 import atexit
 import gettext
+import importlib
 import logging
 import os
 import pathlib
@@ -53,6 +54,14 @@ def initialize_sentry():
     SentryErrorHandling().initialize_sentry()
 
 
+def are_requirements_missing():
+    try:
+        ttLib = importlib.import_module('fontTools.ttLib')
+    except ImportError:
+        return True
+    return False
+
+
 class FileCleanup():
     """
     Allow to register files that will be deleted when the process exits

linux/keyman-config/km-config

@@ -9,7 +9,10 @@ gi.require_version('Gtk', '3.0')
 
 from gi.repository import Gtk
 
-from keyman_config import __versionwithtag__, __pkgversion__, add_standard_arguments, initialize_logging, initialize_sentry, verify_dbus_running
+from keyman_config import (
+  _, __versionwithtag__, __pkgversion__, add_standard_arguments,
+  are_requirements_missing, initialize_logging, initialize_sentry,
+  verify_dbus_running)
 from keyman_config.handle_install import download_and_install_package
 from keyman_config.ibus_util import verify_ibus_daemon
 from keyman_config.view_installed import ViewInstalledWindow
@@ -42,6 +45,18 @@ if __name__ == '__main__':
     initialize_sentry()
     verify_dbus_running()
 
+    if are_requirements_missing():
+        if args.install or args.url:
+            logging.error('Missing requirements. Please install python3-fonttools.')
+        else:
+            dialog = Gtk.MessageDialog(
+                None, 0, Gtk.MessageType.ERROR,
+                Gtk.ButtonsType.OK, _("Missing requirements. Please install python3-fonttools."))
+            dialog.run()
+            dialog.destroy()
+        sys.exit(1)
+
+
     logging.info('Keyman version %s %s', __versionwithtag__, __pkgversion__)
 
     verify_ibus_daemon(False)

linux/keyman-config/km-kvk2ldml

@@ -5,7 +5,9 @@ import logging
 import os
 import sys
 
-from keyman_config import add_standard_arguments, initialize_logging, initialize_sentry, verify_dbus_running
+from keyman_config import (
+  are_requirements_missing, add_standard_arguments, initialize_logging,
+  initialize_sentry, verify_dbus_running)
 from keyman_config.kvk2ldml import parse_kvk_file, print_kvk, convert_ldml, output_ldml
 
 
@@ -25,6 +27,10 @@ def main():
     initialize_sentry()
     verify_dbus_running()
 
+    if are_requirements_missing():
+        logging.error('km-kvk2ldml: Missing requirements. Please install python3-fonttools.')
+        sys.exit(1)
+
     name, ext = os.path.splitext(args.kvkfile)
     # Check if input file extension is kvk
     if ext != ".kvk":