Add flag to stop multiple visualiser processes

Fixes #116

CHANGELOG

@@ -1,3 +1,4 @@
+2022-09-22: [BUGFIX] Stop multiple visualiser processes being spawned by widget
 2022-09-19: [FEATURE] Add `Visualizer` widget
 2022-09-16: [BUGFIX] Fix transparency issue in `PowerLineDecoration`
 2022-09-13: [FEATURE] Add clipping to `RectDecoration`

qtile_extras/widget/visualiser.py

@@ -84,6 +84,7 @@ def __init__(self, **config):
         self._timer = None
         self._draw_count = 0
         self._toggling = False
+        self._starting = False
 
     def _configure(self, qtile, bar):
         if self.cava_path is None:
@@ -117,6 +118,7 @@ def _set_length(self):
         self.length = new
 
     def _start(self):
+        self._starting = True
         self.cava_proc = self.qtile.cmd_spawn([self.cava_path, "-p", self.config_file.name])
         self.draw_proc = self.qtile.cmd_spawn(
             [
@@ -185,6 +187,7 @@ def lock_shm(buffer):
 
         self._take_lock = lock_shm
         self._procs_started = True
+        self._starting = False
         self._set_length()
 
     @contextmanager
@@ -234,7 +237,7 @@ def cmd_stop(self):
 
     def cmd_start(self):
         """Start the visualiser."""
-        if self._procs_started or self._toggling:
+        if self._procs_started or self._toggling or self._starting:
             return
 
         with self.lock_state():