wp_register_widget_control()

wp_register_widget_control() — Registers widget control callback for customizing options.

Inputs: $id (int|string): Sidebar ID. $name (string): Sidebar display name. $control_callback (callable): Run when sidebar is displayed. $options (array): Optional. Array or string of control options. Default empty array. Field $height (int): Never used. Default 200. Field $width (int): Width of the fully expanded control form (but try hard to use the default width). Default 250. Field $id_base (int|string): Required for multi-widgets, i.e widgets that allow multiple instances such as the text widget. The widget ID will end up looking like $id_base-$unique_number.