Define prestart attribute on ButtonMark to place buttons before start

gig.py

@@ -52,6 +52,8 @@ class EventRunner:
         if self._playing is not None:
             return self.activate()
         elif self._selected is not None:
+            if self._next_button_is_prestart:
+                return self.activate()
             self.play()
             return True
         return False
@@ -77,6 +79,7 @@ class EventRunner:
                 print("Scheduled event {} at {} ({} from now)".format(event, event.at, event.at - now))
                 event.scheduled = True
         self._next_button = self._currentitem.get_next_button()
+        self._next_button_is_prestart = self._currentitem.is_button_prestart(self._next_button)
         return True
 
     def stop(self):
@@ -127,7 +130,10 @@ class EventRunner:
                 button = "Select next"
         elif self._selected is not None:
             status = 'Selected {}'.format(self.get_item().get_title())
-            button = "Play"
+            if (self._next_button is not None) and self._next_button_is_prestart:
+                button = "Marker {}".format(self._next_button)
+            else:
+                button = "Play"
         else:
             status = 'Waiting'
             button = "Select"
@@ -249,7 +255,8 @@ class MainWindow(pyglet.window.Window):
                     self.update_cursor(self._cursorpos + 1)
                     self._eventrunner.select(self._cursorpos)
         elif self._selectpos == self._cursorpos:
-            self._eventrunner.play()
+            if not self._eventrunner.advance():
+                self._eventrunner.play()
         else:
             self._eventrunner.select(self._cursorpos)
         self.update_objects()