Fix handler frame for only new scene change

addon/__init__.py

@@ -51,11 +51,21 @@ classes = [
     TOPBAR_HT_upper_bar
 ]
 
-
+last_scene = None
 @persistent
 def on_scene(scene):
+    global last_scene
+    last_scene = bpy.context.scene.name
     if not has_data():
         select_all()
+@persistent
+def on_frame(scene):
+    # Avoid simple playback or frame change (only scene change)
+    global last_scene
+    if bpy.context.scene.name != last_scene:
+        last_scene = bpy.context.scene.name
+        if not has_data():
+            select_all()
 
 og_header = None;
 
@@ -65,7 +75,7 @@ def register():
     for c in classes:
         bpy.utils.register_class(c)
     bpy.types.TOPBAR_MT_workspace_menu.prepend(workspace_menu)
-    bpy.app.handlers.frame_change_post.append(on_scene)
+    bpy.app.handlers.frame_change_post.append(on_frame)
     bpy.app.handlers.load_post.append(on_scene)
     assign_shortcuts()
 
@@ -74,7 +84,7 @@ def unregister():
         bpy.utils.unregister_class(c)
     bpy.utils.register_class(og_header)
     bpy.types.TOPBAR_MT_workspace_menu.remove(workspace_menu)
-    bpy.app.handlers.frame_change_post.remove(on_scene)
+    bpy.app.handlers.frame_change_post.remove(on_frame)
     bpy.app.handlers.load_post.remove(on_scene)
     remove_shortcuts()