Simplify NGL issue handling

src/aiidalab_qe/app/result/components/viewer/structure/structure.py

@@ -9,5 +9,13 @@ class StructureResults(ResultsPanel[StructureResultsModel]):
     identifier = "structure"
 
     def _render(self):
-        self.widget = StructureDataViewer(structure=self._model.outputs.structure)
-        self.children = [self.widget]
+        if not hasattr(self, "widget"):
+            self.widget = StructureDataViewer(structure=self._model.outputs.structure)
+            self.children = [self.widget]
+
+        # HACK to resize the NGL viewer in cases where it auto-rendered when its
+        # container was not displayed, which leads to a null width. This hack restores
+        # the original dimensions.
+        ngl = self.widget._viewer
+        ngl._set_size("100%", "300px")
+        ngl.control.zoom(0.0)

src/aiidalab_qe/common/panel.py

@@ -631,7 +631,11 @@ def __init__(self, model: RM, **kwargs):
         self.links = []
 
     def render(self):
-        if self.rendered or self.has_controls or not self._model.has_process:
+        if self.rendered:
+            if self.identifier == "structure":
+                self._render()
+            return
+        if self.has_controls or not self._model.has_process:
             return
         if not self._model.has_results:
             self._render_controls()
@@ -650,10 +654,7 @@ def _on_load_results_click(self, _):
     def _load_results(self):
         self.children = [self.loading_message]
         self._render()
-        # HACK if this is the structure results panel, we want to
-        # always rerender to refresh the NGL viewer, which does not
-        # handle resize correctly.
-        self.rendered = self._model.identifier != "structure"
+        self.rendered = True
         self._post_render()
         self.has_controls = False