Visual user objects
A visual user object is a reusable control or set of controls
that has a certain behavior. You define it in the User Object painter,
where you place controls in the user object and write scripts for
those controls. Then you can place the user object in windows you
build in your applications as often as needed.
There are three types of visual user objects:
-
Custom visual
Most useful if you frequently group controls together in a
window and always use the controls to perform the same processing. -
External visual
Useful when you have a custom DLL.
-
Standard visual
Most useful if you frequently use a PowerBuilder control to
perform the same processing.
Custom visual user objects
Custom visual user objects are objects that have several controls
that function as a unit. You can think of a custom visual user object
as a window that is a single unit and is used as a control.
Assume you frequently use a group of buttons, each of which
performs standard processing. If you build a custom user object
that contains all the buttons, you can place the buttons in the
window as a unit when you place the user object in a window.
External visual user objects
External visual user objects contain controls from objects
in the underlying windowing system that were created outside PowerBuilder.
You can use a custom DLL in PowerBuilder to create an external user
object.
You must know what classes the DLL supports, the messages
or events the DLL responds to, and the style bits that you can set
in the DLL.
Standard visual user objects
A standard visual user object inherits its definition from
one standard PowerBuilder control. You modify the definition to
make the control specific to your applications.
Assume you frequently use a CommandButton named Close to display
a message box and then close the parent window. If you build a standard
visual user object that derives from a CommandButton to perform
this processing, you can use the user object whenever you want to
display a message box and then close a window.