press space key to pause

indicators.py

@@ -867,15 +867,33 @@ if __name__ == "__main__":
         ),
     ]
 
-    # start button callback
+    app.clientside_callback(
+        """
+            function(id) {
+                document.addEventListener("keyup", function(event) {
+                    if (event.key == ' ') {
+                        document.getElementById('start-button').click()
+                        event.stopPropogation()
+                    }
+                });
+                return window.dash_clientside.no_update       
+            }
+        """,
+        Output("start-button", "id"),
+        Input("start-button", "id")
+    )
+
+    # start / stop button callback
     @callback(Output('interval-component', 'disabled'),
               Output("start-button", "children"),
               Output('controls-and-radio-item', 'disabled'),
-              Input("start-button", "n_clicks"),)
+              Input("start-button", "n_clicks"),
+              State("start-button", "children"),)
     
-    def start_cycle(n):
+    def start_cycle(n, value):
         if n:
-            if n%2 == 0:
+            # if n%2 == 0:
+            if value == "Pause":
                 return True, "Auto Play", False
             else:
                 return False, "Pause", True