SET(WIDGET_CALLBACK) Specifies the DECTPU program or learn sequence to be called by DECTPU when a widget callback occurs for the widget instance. Syntax SET (WIDGET_CALLBACK, widget, program_source, closure) Parameters WIDGET_CALLBACK A keyword directing DECTPU to set the application-level widget callback. widget The widget instance whose callback you want to set. program_source The string, buffer, range, learn sequence, or program specifying the application-level callback. This code is executed when the widget performs a callback to DECTPU. closure A string or integer. DECTPU passes the value to the application when the widget performs a callback to DECTPU. Example The following statement designates the procedure "user_scroll_dispatch" as the callback routine handling events from the scroll bar widget. The statement designates the closure for the callback as the character "h". SET (WIDGET_CALLBACK, scroll_bar_widget, "USER_SCROLL_DISPATCH", "h");