core: If a user specifies --no-gui, don't show GUI messageboxes (#5514)

* move `gui_enabled` to Utils

* docstring

* If a user specified no-gui, don't use GUI messageboxes

---------

Co-authored-by: alwaysintreble <mmmcheese158@gmail.com>

CommonClient.py

@@ -24,7 +24,7 @@ if __name__ == "__main__":
 from MultiServer import CommandProcessor, mark_raw
 from NetUtils import (Endpoint, decode, NetworkItem, encode, JSONtoTextParser, ClientStatus, Permission, NetworkSlot,
                       RawJSONtoTextParser, add_json_text, add_json_location, add_json_item, JSONTypes, HintStatus, SlotType)
-from Utils import Version, stream_input, async_start
+from Utils import gui_enabled, Version, stream_input, async_start
 from worlds import network_data_package, AutoWorldRegister
 import os
 import ssl
@@ -35,9 +35,6 @@ if typing.TYPE_CHECKING:
 
 logger = logging.getLogger("Client")
 
-# without terminal, we have to use gui mode
-gui_enabled = not sys.stdout or "--nogui" not in sys.argv
-
 
 @Utils.cache_argsless
 def get_ssl_context():

Utils.py

@@ -914,6 +914,13 @@ def open_directory(title: str, suggest: str = "") -> typing.Optional[str]:
 
 
 def messagebox(title: str, text: str, error: bool = False) -> None:
+    if not gui_enabled:
+        if error:
+            logging.error(f"{title}: {text}")
+        else:
+            logging.info(f"{title}: {text}")
+        return
+
     if is_kivy_running():
         from kvui import MessageBox
         MessageBox(title, text, error).open()
@@ -949,6 +956,9 @@ def messagebox(title: str, text: str, error: bool = False) -> None:
         root.update()
 
 
+gui_enabled = not sys.stdout or "--nogui" not in sys.argv
+"""Checks if the user wanted no GUI mode and has a terminal to use it with."""
+
 def title_sorted(data: typing.Iterable, key=None, ignore: typing.AbstractSet[str] = frozenset(("a", "the"))):
     """Sorts a sequence of text ignoring typical articles like "a" or "the" in the beginning."""
     def sorter(element: Union[str, Dict[str, Any]]) -> str: