Allow throttle ui: only if openpilot longitudinal (#33787)

check op long

selfdrive/ui/qt/onroad/model.cc

@@ -158,7 +158,7 @@ void ModelRenderer::updatePathGradient(QLinearGradient &bg) {
   constexpr float transition_speed = 0.1f;
 
   // Start transition if throttle state changes
-  bool allow_throttle = (*uiState()->sm)["longitudinalPlan"].getLongitudinalPlan().getAllowThrottle();
+  bool allow_throttle = (*uiState()->sm)["longitudinalPlan"].getLongitudinalPlan().getAllowThrottle() || !longitudinal_control;
   if (allow_throttle != prev_allow_throttle) {
     prev_allow_throttle = allow_throttle;
     // Invert blend factor for a smooth transition when the state changes mid-animation

selfdrive/ui/qt/onroad/model.h

@@ -26,7 +26,7 @@ private:
   bool longitudinal_control = false;
   bool experimental_mode = false;
   float blend_factor = 1.0f;
-  bool prev_allow_throttle = false;
+  bool prev_allow_throttle = true;
   float lane_line_probs[4] = {};
   float road_edge_stds[2] = {};
   QPolygonF track_vertices;