Launcher: keep alive (ArchipelagoMW#1894)

Launcher.py

@@ -223,6 +223,12 @@ def component_action(button):
             else:
                 launch(get_exe(button.component), button.component.cli)
 
+        def _stop(self, *largs):
+            # ran into what appears to be https://groups.google.com/g/kivy-users/c/saWDLoYCSZ4 with PyCharm.
+            # Closing the window explicitly cleans it up.
+            self.root_window.close()
+            super()._stop(*largs)
+
     Launcher().run()
 
 
@@ -267,3 +273,9 @@ def main(args: Optional[Union[argparse.Namespace, dict]] = None):
                         help="Pass either a patch file, a generated game or the name of a component to run.")
     parser.add_argument('args', nargs="*", help="Arguments to pass to component.")
     main(parser.parse_args())
+
+    from worlds.LauncherComponents import processes
+    for process in processes:
+        # we await all child processes to close before we tear down the process host
+        # this makes it feel like each one is its own program, as the Launcher is closed now
+        process.join()

worlds/LauncherComponents.py

@@ -1,3 +1,4 @@
+import weakref
 from enum import Enum, auto
 from typing import Optional, Callable, List, Iterable
 
@@ -48,10 +49,14 @@ def handles_file(self, path: str):
     def __repr__(self):
         return f"{self.__class__.__name__}({self.display_name})"
 
+processes = weakref.WeakSet()
+
 def launch_subprocess(func: Callable, name: str = None):
+    global processes
     import multiprocessing
-    process = multiprocessing.Process(target=func, name=name, daemon=True)
+    process = multiprocessing.Process(target=func, name=name)
     process.start()
+    processes.add(process)
 
 class SuffixIdentifier:
     suffixes: Iterable[str]