added button that can run coroutines

tkasyncio/tkasyncio.py

@@ -12,19 +12,26 @@ def __init__(self):
         super().__init__()
         self.running = True
         self.runners = [self.tk_loop()]
+        self.button_presses = []
 
     async def tk_loop(self):
         "asyncio 'compatible' tk event loop?"
         # Is there a better way to trigger loop exit than using a state vrbl?
         while self.running:
             self.update()
             await asyncio.sleep(0.05) # obviously, sleep time could be parameterized
+            if len(self.button_presses) > 0:
+                await self.button_presses.pop(0)
 
     def stop(self):
         self.running = False
 
     async def run(self):
         await asyncio.gather(*self.runners)
+
+    def add_button_coro(self, coro):
+        task = asyncio.create_task(coro)
+        self.button_presses.append(task)
 
 
 class App(AsyncTk):
@@ -40,6 +47,8 @@ def create_interface(self):
         b1.pack()
         b2 = Button(master=self, text='Quit', command=self.stop)
         b2.pack()
+        b3 = Button(master=self, text='Foo', command=lambda: self.add_button_coro(self.foo()))
+        b3.pack()
 
     async def counter(self):
         "sample async worker... (with apologies to Lawrence Welk)"
@@ -48,6 +57,11 @@ async def counter(self):
             print("and a", i)
             await asyncio.sleep(1)
             i += 1
+
+    async def foo(self):
+        print(f"IO task foo has started")
+        await asyncio.sleep(1)
+        print(f"IO task foo has finished")
 
 async def main():
     app = App()