- fixed Measuring Tool - after doing a measurement the Notebook was switching to Project Tab without letting the user see the results

- more work on the translation engine; the app now restarts after a language is applied
- added protection against using Travel Z parameter with negative or zero value (in Geometry).

FlatCAMTranslation.py

@@ -1,11 +1,16 @@
 import os
-from datetime import datetime
+import sys
+
+from PyQt5 import QtWidgets, QtGui
+from PyQt5.QtCore import QSettings
 
 import FlatCAMApp
-from FlatCAMApp import log
+from GUIElements import log
+import gettext
 
 # ISO639-1 codes from here: https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
 languages_dict = {
+    'zh': 'Chinese',
     'de': 'German',
     'en': 'English',
     'es': 'Spanish',
@@ -13,7 +18,6 @@ languages_dict = {
     'it': 'Italian',
     'ro': 'Romanian',
     'ru': 'Russian',
-    'zh': 'Chinese',
 }
 
 translations = {}
@@ -21,8 +25,8 @@ translations = {}
 languages_path_search = ''
 
 
-def load_languages(app):
-    languages_path_search = os.path.join('locale')
+def load_languages():
+    languages_path_search = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'locale')
 
     available_translations = next(os.walk(languages_path_search))[1]
 
@@ -35,5 +39,79 @@ def load_languages(app):
     return translations
 
 
-def languages_dir(app):
-    return os.path.join('locale')
+def languages_dir():
+    return os.path.join(os.path.dirname(os.path.abspath(__file__)), 'locale')
+
+
+def on_language_apply_click(app, restart=False):
+    """
+    Using instructions from here:
+    https://inventwithpython.com/blog/2014/12/20/translate-your-python-3-program-with-the-gettext-module/
+
+    :return:
+    """
+    name = app.ui.general_defaults_form.general_app_group.language_cb.currentText()
+
+    if restart:
+        msgbox = QtWidgets.QMessageBox()
+
+        msgbox.setInformativeText("Are you sure do you want to change the current language to %s?\n\n"
+                                  "The application will restart." % name.capitalize())
+        msgbox.setWindowTitle("Apply Language ...")
+        msgbox.setWindowIcon(QtGui.QIcon('share/save_as.png'))
+        msgbox.setStandardButtons(QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.Cancel)
+        msgbox.setDefaultButton(QtWidgets.QMessageBox.Yes)
+
+        response = msgbox.exec_()
+
+        if response == QtWidgets.QMessageBox.Cancel:
+            return
+        else:
+            settings = QSettings("Open Source", "FlatCAM")
+            saved_language = name
+            settings.setValue('language', saved_language)
+            # This will write the setting to the platform specific storage.
+            del settings
+
+            restart_program(app=app)
+
+
+def apply_language(filename, lang=None):
+    lang_code = ''
+
+    if lang is None:
+        settings = QSettings("Open Source", "FlatCAM")
+        if settings.contains("language"):
+            name = settings.value('language')
+        else:
+            name = settings.value('English')
+    else:
+        name = str(lang)
+
+    for lang_code, lang_usable in load_languages().items():
+        if lang_usable == name:
+            # break and then use the current key as language
+            break
+
+    if lang_code == '':
+        return "no language"
+    else:
+        try:
+            current_lang = gettext.translation(str(filename), localedir=languages_dir(), languages=[lang_code])
+            current_lang.install()
+        except Exception as e:
+            log.debug("FlatCAMTranslation.apply_language() --> %s" % str(e))
+
+        return name
+
+
+def restart_program(app):
+    """Restarts the current program.
+    Note: this function does not return. Any cleanup action (like
+    saving data) must be done before calling this function.
+    """
+    app.save_defaults()
+    python = sys.executable
+    os.execl(python, python, *sys.argv)
+
+