HP 3000 Manuals HP 3000 Manuals
VCHANGEFIELD Limitations VCHANGEFIELD relies on VSHOWFORM for the application of field video attribute alterations to the form image on the physical terminal screen. VCHANGEFIELD can alter the following field video attributes: * Field type (input or display only). * Field enhancement (inverse, blinking, underlined, and so on). VSHOWFORM display optimization may bypass the internal data structure that carries the VCHANGEFIELD screen updates. This could cause previously applied field changes to not register on subsequent updates, because the factors driving the optimization can change from one VSHOWFORM call to the next call. Application programmers should thoroughly verify all aspects of user interfaces when using VCHANGEFIELD. Verification should include all field alteration permutations that the application may invoke across all screen display/redisplay combinations. Before using VCHANGEFIELD, consider creating a forms family as a more satisfactory alternative. Forms families enable FORMSPEC to manage form image issues during form design.