feat: 完善 STEP 编辑器最小系统和稳定性

step_editor/info_panel.py

@@ -27,6 +27,8 @@ class InfoPanelMixin:
         self.info_text.setPlainText(self.current_info_text)
         self._populate_info_tree(info)
         self.info_tabs.setCurrentWidget(self.info_tree)
+        if hasattr(self, "export_all_button"):
+            self._update_action_states()
 
     def set_plain_info(self, text: str) -> None:
         self.current_info_values = {}
@@ -34,6 +36,8 @@ class InfoPanelMixin:
         self.info_tree.clear()
         self.info_text.setPlainText(text)
         self.info_tabs.setCurrentWidget(self.info_text)
+        if hasattr(self, "export_all_button"):
+            self._update_action_states()
 
     def _populate_info_tree(self, info: dict[str, object]) -> None:
         self.info_tree.clear()
@@ -106,6 +110,7 @@ class InfoPanelMixin:
             self.measure_label_b = source
             self.statusBar().showMessage(f"已设置测量点 B: {_format_value(point)}")
         self._refresh_measurement_panel()
+        self._update_action_states()
 
     def clear_measurement(self) -> None:
         self.measure_point_a = None
@@ -115,6 +120,7 @@ class InfoPanelMixin:
         self._clear_measure_actor()
         self._refresh_measurement_panel()
         self.statusBar().showMessage("已清除测量")
+        self._update_action_states()
 
     def copy_measurement(self) -> None:
         text = self.measure_text.toPlainText() if hasattr(self, "measure_text") else ""