Core: Launcher: can drag-and-drop patch on Launcher window (#3442)

* Core: Launcher: can drag-and-drop patch on Launcher window

* doc string for `_on_drop_file`

Launcher.py

@@ -162,6 +162,7 @@ def launch(exe, in_terminal=False):
 
 def run_gui():
     from kvui import App, ContainerLayout, GridLayout, Button, Label, ScrollBox, Widget
+    from kivy.core.window import Window
     from kivy.uix.image import AsyncImage
     from kivy.uix.relativelayout import RelativeLayout
 
@@ -226,6 +227,8 @@ def build_button(component: Component) -> Widget:
                 if client:
                     client_layout.layout.add_widget(build_button(client[1]))
 
+            Window.bind(on_drop_file=self._on_drop_file)
+
             return self.container
 
         @staticmethod
@@ -235,6 +238,14 @@ def component_action(button):
             else:
                 launch(get_exe(button.component), button.component.cli)
 
+        def _on_drop_file(self, window: Window, filename: bytes, x: int, y: int) -> None:
+            """ When a patch file is dropped into the window, run the associated component. """
+            file, component = identify(filename.decode())
+            if file and component:
+                run_component(component, file)
+            else:
+                logging.warning(f"unable to identify component for {filename}")
+
         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.

typings/kivy/core/window.pyi

@@ -0,0 +1,15 @@
+from typing import Callable, ClassVar
+
+from kivy.event import EventDispatcher
+
+
+class WindowBase(EventDispatcher):
+    width: ClassVar[int]  # readonly AliasProperty
+    height: ClassVar[int]  # readonly AliasProperty
+
+    @staticmethod
+    def bind(**kwargs: Callable[..., None]) -> None: ...
+
+
+class Window(WindowBase):
+    ...

typings/kivy/event.pyi

@@ -0,0 +1,2 @@
+class EventDispatcher:
+    ...