diff --git a/Hardware/Widgets/EventWidget.cpp b/Hardware/Widgets/EventWidget.cpp
index acb565a..d12a395 100644
--- a/Hardware/Widgets/EventWidget.cpp
+++ b/Hardware/Widgets/EventWidget.cpp
@@ -35,20 +35,18 @@ int EventWidget::height() const
 
 void EventWidget::set_y_height(int state_y)
 {
-  static_cast<TimeSyncWidget*>(parent)->set_y_height(state_y);
+  static_cast<TimeSyncWidget*>(bugui::base_widget::parent)->set_y_height(state_y);
 
-  if (state_y < m_y) m_y = state_y - parent->y();
-  if (state_y > m_height) m_height = state_y - parent->y();
+  int sy = state_y - bugui::base_widget::parent->y();
+  if (sy < m_y) m_y = sy;
+  if (sy > m_height) m_height = sy;
 }
 
 void EventWidget::set_y_height()
 {
-  static_cast<TimeSyncWidget*>(parent)->set_y_height();
+  static_cast<TimeSyncWidget*>(bugui::base_widget::parent)->set_y_height();
 
-  m_y = std::numeric_limits<int>::max();
-  m_height = std::numeric_limits<int>::lowest();
-
-  for(const auto& s : children)
+  for(const auto& s : bugui::container_widget::children)
   {
     int sy = s->y();
     if (sy < m_y) m_y = sy;
@@ -79,8 +77,6 @@ void EventWidget::on_state_added(Scenario::StateModel& state)
   if (state.eventId() != model.id()) return;
 
   add_widget<StateWidget>(state, scenario);
-
-  set_y_height();
 }
 
 void EventWidget::on_state_removed(const Scenario::StateModel& state)
@@ -92,6 +88,7 @@ void EventWidget::on_state_removed(const Scenario::StateModel& state)
   { return static_cast<ScenarioComponent<>*>(w.get())->this_model(state); });
 
   set_y_height();
+  update();
 }
 
 void EventWidget::on_press(int x, int y, bool pressed)
@@ -99,4 +96,4 @@ void EventWidget::on_press(int x, int y, bool pressed)
   qDebug() << "is inside!";
 }
 
-}
+} // namespace Hardware
diff --git a/Hardware/Widgets/EventWidget.hpp b/Hardware/Widgets/EventWidget.hpp
index 4bd48bd..0145c14 100644
--- a/Hardware/Widgets/EventWidget.hpp
+++ b/Hardware/Widgets/EventWidget.hpp
@@ -13,14 +13,13 @@ struct EventWidget final : Nano::Observer
                        ScenarioWidget* scenario,
                        bugui::container_widget* parent);
 
-
   int y() const override;
   int height() const override;
 
   void set_y_height(int state_y);
   void set_y_height();
 
-protected:
+private:
   bool contains(int px, int py) const override;
 
   void paint(bugui::painter& painter) const override;
diff --git a/Hardware/Widgets/ScenarioWidget.hpp b/Hardware/Widgets/ScenarioWidget.hpp
index 581e7f9..2fde41b 100644
--- a/Hardware/Widgets/ScenarioWidget.hpp
+++ b/Hardware/Widgets/ScenarioWidget.hpp
@@ -6,9 +6,8 @@
 
 namespace Hardware
 {
-class ScenarioWidget final
-    : public bugui::container_widget
-    , public Nano::Observer
+class ScenarioWidget final : public bugui::container_widget
+                           , public Nano::Observer
 {
 public:
   explicit ScenarioWidget(Scenario::ProcessModel* scenario,
diff --git a/Hardware/Widgets/StateWidget.cpp b/Hardware/Widgets/StateWidget.cpp
index f3b2135..2a0c31e 100644
--- a/Hardware/Widgets/StateWidget.cpp
+++ b/Hardware/Widgets/StateWidget.cpp
@@ -14,33 +14,22 @@ StateWidget::StateWidget(Scenario::StateModel& state,
   connect(&model,
           &Scenario::StateModel::heightPercentageChanged,
           this,
-          [parent, scenario, this]
-  {
-    static_cast<EventWidget*>(parent)->set_y_height(
-        model.heightPercentage() * scenario->height());
-  });
+          &StateWidget::set_y);
 
-  static_cast<EventWidget*>(parent)->set_y_height(
-      model.heightPercentage() * scenario->height());
-
-  update();
+  set_y();
 }
 
 StateWidget::~StateWidget()
 {
-  disconnect(&model,
-             &Scenario::StateModel::heightPercentageChanged,
-             this, 0);
-
-  update();
+  // disconnect(&model,
+  //            &Scenario::StateModel::heightPercentageChanged,
+  //            this,
+  //            &StateWidget::set_y);
 }
 
 int StateWidget::y() const
 {
-  // FIXME : this seems very dirty !
-  return model.heightPercentage() * scenario->height() -
-         bugui::base_widget::parent->get_parent()->y() -
-         bugui::base_widget::parent->y();
+  return m_y;
 }
 
 void StateWidget::paint(bugui::painter& painter) const
@@ -75,6 +64,19 @@ void StateWidget::on_drag(int from_x, int from_y, int to_x, int to_y)
   model.setHeightPercentage(model.heightPercentage() + increment);
 }
 
+void StateWidget::set_y()
+{
+  static_cast<EventWidget*>(bugui::base_widget::parent)->set_y_height(
+      model.heightPercentage() * scenario->height());
+
+  // FIXME : this seems very dirty !
+  m_y = model.heightPercentage() * scenario->height() -
+        bugui::base_widget::parent->get_parent()->y() -
+        bugui::base_widget::parent->y();
+
+  update();
+}
+
 } // namespace Hardware
 
 #include <wobjectimpl.h>
diff --git a/Hardware/Widgets/StateWidget.hpp b/Hardware/Widgets/StateWidget.hpp
index bdb89c0..bbc18ed 100644
--- a/Hardware/Widgets/StateWidget.hpp
+++ b/Hardware/Widgets/StateWidget.hpp
@@ -26,6 +26,10 @@ private:
   void on_press(int x, int y, bool pressed) override;
   void on_double_press(int x, int y) override;
   void on_drag(int from_x, int from_y, int to_x, int to_y) override;
+
+  void set_y();
+
+  int m_y;
 };
 
 } //namespace Hardware
diff --git a/Hardware/Widgets/TimeSyncWidget.cpp b/Hardware/Widgets/TimeSyncWidget.cpp
index 494c1a1..c2698d7 100644
--- a/Hardware/Widgets/TimeSyncWidget.cpp
+++ b/Hardware/Widgets/TimeSyncWidget.cpp
@@ -32,6 +32,12 @@ TimeSyncWidget::TimeSyncWidget(Scenario::TimeSyncModel& timeSync,
                   (const auto& w)
     { return static_cast<ScenarioComponent<>*>(w.get())->this_model(eventId); });
   });
+
+  Scenario::ProcessModel* scen{scenario->get_model()};
+
+  for(Scenario::EventModel& e : scen->events)
+    if (e.timeSync() == model.id())
+      add_widget<EventWidget>(e, scenario);
 }
 
 TimeSyncWidget::~TimeSyncWidget()
@@ -72,9 +78,6 @@ void TimeSyncWidget::set_y_height(int event_y)
 
 void TimeSyncWidget::set_y_height()
 {
-  m_y = std::numeric_limits<int>::max();
-  m_height = std::numeric_limits<int>::lowest();
-
   for(const auto& e : bugui::container_widget::children)
   {
     int ey = e->y();