set previous active style and context values editing material's style

src/blenderbim/blenderbim/bim/module/material/operator.py

@@ -728,6 +728,20 @@ class EnableEditingMaterialStyle(bpy.types.Operator, tool.Ifc.Operator):
         props.active_material_id = self.material
         props.editing_material_type = "STYLE"
 
+        # set already applied style and context if possible
+        if not 0 <= props.active_material_index < len(props.materials):
+            return
+
+        material = tool.Ifc.get().by_id(props.materials[props.active_material_index].ifc_definition_id)
+        if not material.HasRepresentation:
+            return
+
+        rep = material.HasRepresentation[0].Representations[0]  # IfcStyledRepresentation
+        props.contexts = str(rep.ContextOfItems.id())
+        style = rep.Items[0].Styles[0]
+        if style.Name:  # props.styles only has named styles
+            props.styles = str(rep.Items[0].Styles[0].id())
+
 
 class EditMaterialStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_material_style"

src/blenderbim/blenderbim/bim/module/material/ui.py

@@ -81,6 +81,8 @@ class BIM_PT_materials(Panel):
 
         self.layout.template_list("BIM_UL_materials", "", self.props, "materials", self.props, "active_material_index")
 
+        # TODO: data.py is not updated on changing active_material_index
+        # so the active material styles go out of sync with the active material
         for style in MaterialsData.data["active_styles"]:
             row = self.layout.row(align=True)
             row.label(text="", icon="SHADING_RENDERED")