There are five form-level events sent by the Form Manager to an application:
This specifies that a form needs to be loaded. While there is no default handling for this event, this is certainly the event for which your application-wide event handler is looking (see Chapter 5). In response to this event, the event handler must do the following:
Initialize the form
Make it the active form
Install an event handler for it
This specifies that a form is being opened. There is no default handling for this event. Your form-specific event handler needs to draw the form (after initializing any form objects that it desires).
Do not do any drawing to the screen before calling
(the 3.5 or later debug ROMs will cause an
error if you try). You may do initialization of form objects, which
will then draw with their new values when the form itself draws.
Since the bits underneath for the form are saved on the first
FrmDrawForm (see Section 8.2 earlier), you don’t want to do
any drawing before that, or the wrong bits will be saved.
This is sent when a form is being closed. The default handling for
this event is to erase the form (restoring the bits underneath, if
Save Behind is set), and delete it from memory.
You’ll often want to look for this event so as to undo the
effects of any initialization you did on the
frmOpenEvent (e.g., deallocate allocated memory). You’ll still want to return false from your event handler, however, ...