Fix race condition before the window is created

README.md

@@ -31,7 +31,7 @@ This tool is a plain Omniverse extension that can be installed as any other exte
 1. Download the release or clone the repository into your computer.
 2. In the Omniverse App (Create, Code, etc.), open the Extensions window from: Window menu > Extensions.
 3. In the Extensions window, open the Settings page, by clicking the small gear button at the top of the left bar.
-4. In the Settings page that appears at the right appears a list of Extension Search Paths. Add the path location of the exts/ subfolder. This subfolder is inside the location to where you installed in step 1.
+4. In the Settings page that appears at the right, you'll see a list of Extension Search Paths. Add the path location of the exts/ subfolder. This subfolder is inside the location to where you installed in step 1.
 5. In the search field at the top left bar, next to the gear button, type model exploder - the tool should appear listed - click it.
 6. information about the Model Exploder tool will appear at the right side: check the Enabled and the Autoload checkboxes. The tool is now installed in your Omniverse app.
 

exts/syntway.model_exploder/syntway/model_exploder/libs/app_utils.py

@@ -13,7 +13,7 @@
 from pxr import Gf, Tf, Sdf, Usd, UsdGeom, CameraUtil
 
 
-VERSION = 10
+VERSION = 11
 
 
 def call_after_update(fn, update_count=1):
@@ -141,6 +141,9 @@ def set_setting(path, value):
     carb.settings.get_settings().set(path, value)
 
 
+def delete_setting(path):
+    carb.settings.get_settings().destroy_item(path)
+
 
 def get_extension_path(ext_id, sub_path=None):
     ext_path = omni.kit.app.get_app().get_extension_manager().get_extension_path(ext_id)

exts/syntway.model_exploder/syntway/model_exploder/window.py

@@ -57,6 +57,7 @@ def __init__(self, title: str, ext_id: str, **kwargs):
 
         self.auto_resize = True
 
+        self._ui_built = False
         self.frame.set_build_fn(self._build_fn)
 
         self._vp = ViewportHelper()
@@ -279,6 +280,8 @@ def get_dist_mult_index(dist_mult):
                 #ui.Button("Test", clicked_fn=self._on_test)
 
 
+        self._ui_built = True
+
         self._refresh_ui()
 
 
@@ -288,6 +291,9 @@ def get_dist_mult_index(dist_mult):
     def _on_stage_event(self, ev: carb.events.IEvent):
         # print("Window._on_stage_event", ev.type)
 
+        if not self._ui_built:  # a stage event can call us before _build_fn()
+            return
+
         if ev.type == int(omni.usd.StageEventType.SELECTION_CHANGED):
             if not self._engine.has_meshes:
                 self._refresh_ui()