Function undo_entry_fn 

pub fn undo_entry_fn(
    child: impl IntoUiNode,
    wgt_fn: impl IntoVar<WidgetFn<UndoEntryArgs>>,
) -> UiNode

P Widget function that converts UndoEntryArgs to widgets.

Try undo_redo_button_style_fn for making only visual changes.

Sets the UNDO_ENTRY_FN_VAR.