fix(dock): properly shut down docks and dock areas

bec_widgets/widgets/dock/dock.py

@@ -319,6 +319,8 @@ class BECDock(BECWidget, Dock):
             if hasattr(widget, "cleanup"):
                 widget.cleanup()
         self.widgets.clear()
+        self.label.close()
+        self.label.deleteLater()
         super().cleanup()
 
     def close(self):

bec_widgets/widgets/dock/dock_area.py

@@ -231,6 +231,7 @@ class BECDockArea(BECWidget, QWidget):
         self.config.docks.pop(name, None)
         if dock:
             dock.close()
+            dock.deleteLater()
             if len(self.dock_area.docks) <= 1:
                 for dock in self.dock_area.docks.values():
                     dock.hide_title_bar()
@@ -345,6 +346,10 @@ class BECDockArea(BECWidget, QWidget):
         Cleanup the dock area.
         """
         self.clear_all()
+        self.toolbar.close()
+        self.toolbar.deleteLater()
+        self.dock_area.close()
+        self.dock_area.deleteLater()
         super().cleanup()
 
     def close(self):

bec_widgets/widgets/figure/plots/image/image.py

@@ -686,6 +686,8 @@ class BECImageShow(BECPlotBase):
         """Cleanup pyqtgraph items."""
         super().cleanup_pyqtgraph()
         item = self.plot_item
+        if not item.items:
+            return
         cbar = item.items[0].color_bar
         cbar.vb.menu.close()
         cbar.vb.menu.deleteLater()

bec_widgets/widgets/image/image_widget.py

@@ -458,6 +458,8 @@ class BECImageWidget(BECWidget, QWidget):
     def cleanup(self):
         self.fig.cleanup()
         self.client.shutdown()
+        self.toolbar.close()
+        self.toolbar.deleteLater()
         return super().cleanup()