Brew MP 1.0.2
This function will request that a form activate itself -- for example, when that
form is brought to the top of the form stack and becomes the visible form on the
display. The form should respond in whatever manner is appropriate for its specific
needs. For example, a form that defines a container widget (which, in turn, holds
text, images and other controls) could give the focus to the container and trigger
a trickle down effect of activation to all the child widgets on the form.
During activation FID_PREFRECT is requested from the form to allow the form to
indicate the preferred rectangle (position and size) in screen co-ordinates of
the form widget.
void IForm_Activate(IForm *pif);
Calling IForm_Activate() effectively sets the FID_ACTIVE property on the form,
as the current activation state.