Internationalization - Proof of Concept

default_config.json

@@ -8,6 +8,7 @@
         "gps_lock": false,
         "timezone": "America/Los_Angeles"
     },
+    "language": "en",
     "camera_exp": 400000,
     "camera_gain": 20,
     "menu_anim_speed": 0.1,

python/PiFinder/main.py

@@ -10,6 +10,8 @@
 
 """
 
+import gettext
+
 import os
 
 # skyfield performance fix, see: https://rhodesmill.org/skyfield/accuracy-efficiency.html
@@ -51,6 +53,12 @@
 from PiFinder.calc_utils import sf_utils
 from PiFinder.displays import DisplayBase, get_display
 
+# Install the _("text") into global context for Internationalization
+# On RasPi/Ubuntu the default locale is C.utf8, see `locale -a`, which locales are available
+# You need to install `apt install language-pack_xx`, where xx is the ISO country code.
+# Passing nothing as third parameter means the language is determined from environment variables (e.g. LANG)
+gettext.install("PiFinder", "locale")
+
 logger = logging.getLogger("main")
 
 hardware_platform = "Pi"
@@ -287,6 +295,13 @@ def main(
     screen_brightness = cfg.get_option("display_brightness")
     set_brightness(screen_brightness, cfg)
 
+    # Set user interface language
+    lang = cfg.get_option("language")
+    langXX = gettext.translation(
+        "messages", "locale", languages=[lang], fallback=(lang == "en")
+    )
+    langXX.install()
+
     import PiFinder.manager_patch as patch
 
     patch.apply()
@@ -722,6 +737,10 @@ def rotate_logs() -> Path:
     return utils.data_dir / "pifinder.log"
 
 
+#############################################################################################
+#############################################################################################
+#############################################################################################
+
 if __name__ == "__main__":
     print("Bootstrap logging configuration ...")
     logging.basicConfig(format="%(asctime)s BASIC %(name)s: %(levelname)s %(message)s")
@@ -803,6 +822,11 @@ def rotate_logs() -> Path:
         "-x", "--verbose", help="Set logging to debug mode", action="store_true"
     )
     parser.add_argument("-l", "--log", help="Log to file", action="store_true")
+    parser.add_argument(
+        "--lang",
+        help="Force user interface language (iso2 code). Changes configuration",
+        type=str,
+    )
     args = parser.parse_args()
     # add the handlers to the logger
     if args.verbose:
@@ -850,7 +874,13 @@ def rotate_logs() -> Path:
     elif args.keyboard.lower() == "none":
         from PiFinder import keyboard_none as keyboard  # type: ignore[no-redef]
 
-        rlogger.warn("using no keyboard")
+        rlogger.warning("using no keyboard")
+
+    if args.lang:
+        if args.lang.lower() not in ["en", "de", "fr", "es"]:
+            raise Exception(f"Unknown language '{args.lang}' passed via command line.")
+        else:
+            config.Config().set_option("language", args.lang)
 
     # if args.log:
     #    datenow = datetime.datetime.now()

python/PiFinder/sys_utils.py

@@ -2,6 +2,7 @@
 import re
 from typing import Dict, Any
 
+
 try:
     import sh
     from sh import wpa_cli, unzip, su, passwd

python/PiFinder/ui/callbacks.py

@@ -10,11 +10,19 @@
 
 import datetime
 import logging
+import gettext
 
+from typing import Any, TYPE_CHECKING
 from PiFinder import utils
 from PiFinder.ui.base import UIModule
 from PiFinder.catalogs import CatalogFilter
 
+if TYPE_CHECKING:
+
+    def _(a) -> Any:
+        return a
+
+
 sys_utils = utils.get_sys_utils()
 
 
@@ -40,7 +48,7 @@ def reset_filters(ui_module: UIModule) -> None:
 
     ui_module.catalogs.set_catalog_filter(new_filter)
     ui_module.catalogs.filter_catalogs()
-    ui_module.message("Filters Reset")
+    ui_module.message(_("Filters Reset"))
     ui_module.remove_from_stack()
     return
 
@@ -54,7 +62,7 @@ def activate_debug(ui_module: UIModule) -> None:
     ui_module.command_queues["console"].put("Debug: Activated")
     dt = datetime.datetime(2024, 6, 1, 2, 0, 0)
     ui_module.shared_state.set_datetime(dt)
-    ui_module.message("Test Mode")
+    ui_module.message(_("Test Mode"))
 
 
 def set_exposure(ui_module: UIModule) -> None:
@@ -70,7 +78,7 @@ def shutdown(ui_module: UIModule) -> None:
     """
     shuts down the Pi
     """
-    ui_module.message("Shutting Down", 10)
+    ui_module.message(_("Shutting Down"), 10)
     sys_utils.shutdown()
 
 
@@ -79,26 +87,26 @@ def restart_pifinder(ui_module: UIModule) -> None:
     Uses systemctl to restart the PiFinder
     service
     """
-    ui_module.message("Restarting...", 2)
+    ui_module.message(_("Restarting..."), 2)
     sys_utils.restart_pifinder()
 
 
 def restart_system(ui_module: UIModule) -> None:
     """
     Restarts the system
     """
-    ui_module.message("Restarting...", 2)
+    ui_module.message(_("Restarting..."), 2)
     sys_utils.restart_system()
 
 
 def switch_cam_imx477(ui_module: UIModule) -> None:
-    ui_module.message("Switching cam", 2)
+    ui_module.message(_("Switching cam"), 2)
     sys_utils.switch_cam_imx477()
     restart_system(ui_module)
 
 
 def switch_cam_imx296(ui_module: UIModule) -> None:
-    ui_module.message("Switching cam", 2)
+    ui_module.message(_("Switching cam"), 2)
     sys_utils.switch_cam_imx296()
     restart_system(ui_module)
 
@@ -127,13 +135,24 @@ def get_camera_type(ui_module: UIModule) -> list:
     return [cam_id]
 
 
+def switch_language(ui_module: UIModule) -> None:
+    iso2_code = ui_module.config_object.get_option("language")
+    msg = str(f"Language: {iso2_code}")
+    ui_module.message(_(msg))
+    lang = gettext.translation(
+        "messages", "locale", languages=[iso2_code], fallback=(iso2_code == "en")
+    )
+    lang.install()
+    logger.info("Switch Language: %s", iso2_code)
+
+
 def go_wifi_ap(ui_module: UIModule) -> None:
-    ui_module.message("WiFi to AP", 2)
+    ui_module.message(_("WiFi to AP"), 2)
     sys_utils.go_wifi_ap()
     restart_system(ui_module)
 
 
 def go_wifi_cli(ui_module: UIModule) -> None:
-    ui_module.message("WiFi to Client", 2)
+    ui_module.message(_("WiFi to Client"), 2)
     sys_utils.go_wifi_cli()
     restart_system(ui_module)