Form and window coexistence
- Last Updated: March 30, 2020
- 1 minute read
- OpenEdge
- Version 12.2
- Documentation
Form and window coexistence
To allow forms and windows to coexist in an application, several
ABL enhancements work to tie them together. A FormProxy object
is a wrapper that is created for every ABL window. Similar to a
form, the FormProxy allows the window to reside
on the form chain, which is a list of all running forms.
Except for the default window, a FormProxy is created
for windows that are explicitly created in the session, not for
windows created internally by the AVM. The AVM maintains form proxies,
automatically creating and destroying them. Even though you do not
work with FormProxy objects directly, it is helpful
to know about them, since they exist on the form chain.
A shadow window widget, which is created for every form, provides a means of parenting a window to a form. The shadow window has no visualization.