PV Area, Introduction
version 6.8
The routines of this theme allow managing off-screen areas and external areas displayed in forms. The allow you to create or erase an off-screen area, to paste the content of a field or a BLOB variable in an external area or off-screen, or to save a 4D View area in a field or a BLOB variable.
Additionally, this theme gathers commands allowing the programmer to intercept different types of events detected by a 4D View area, to build their own error manager and also manage 4D View commands accessible using menus or palettes.
Callback methods
In this theme, several commands make reference to the "callback" concept: this mechanism is used here to link a method to an event, error or 4D View command. Every time 4D View detects an event, error or the activation of a menu command, the 4D project method defined by the area settings is executed: in this context, this method is called a "callback method".
The PV Area theme commands that make reference to callback methods are: