Fix issue BrowseExternalStyle not selecting current external style in file manager

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

@@ -240,10 +240,17 @@ class BrowseExternalStyle(bpy.types.Operator):
         description="Start file browsing directory",
         default="",
     )
+    active_surface_style_id: bpy.props.IntProperty(
+        description="Currently selected IfcSurfaceStyle ID to automatically select it in the file browser",
+        options={"HIDDEN", "SKIP_SAVE"},
+    )
 
     def invoke(self, context, event):
-        mat = context.active_object.active_material
-        external_style = tool.Style.get_style_elements(mat).get("IfcExternallyDefinedSurfaceStyle", None)
+        external_style = None
+        if self.active_surface_style_id:
+            style = tool.Ifc.get().by_id(self.active_surface_style_id)
+            external_style = tool.Style.get_style_elements(style).get("IfcExternallyDefinedSurfaceStyle", None)
+
         # automatically select previously selected external style in file browser
         if external_style and self.filepath == "":
             style_path = Path(tool.Ifc.resolve_uri(external_style.Location))

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

@@ -233,7 +233,10 @@ class BIM_PT_styles(Panel):
         row.operator("bim.disable_editing_style", text="", icon="CANCEL")
 
     def draw_externally_defined_surface_style(self):
-        self.layout.row().operator("bim.browse_external_style", icon="APPEND_BLEND", text="Append From Blend File")
+        row = self.layout.row()
+        op = row.operator("bim.browse_external_style", icon="APPEND_BLEND", text="Append From Blend File")
+        style = self.props.styles[self.props.active_style_index]
+        op.active_surface_style_id = style.ifc_definition_id
         blenderbim.bim.helper.draw_attributes(self.props.external_style_attributes, self.layout)
         row = self.layout.row(align=True)
         row.operator("bim.edit_surface_style", text="Save External Style", icon="CHECKMARK")