Chapter 1 -- 2
Programmer’s Guide
What is an ActiveX object?
An ActiveX object is an instance of a class that exposes
properties, methods, and events to ActiveX clients. ActiveX
objects support the COM (Component Object Model) - Microsoft
technology. An ActiveX component is an application or library
that is able to create one or more ActiveX objects. In this case,
your labeling software exposes many objects that you can use to
create new applications and programming tools. Within your
labeling software, objects are organized hierarchically, with an
object named
Application
at the top of the hierarchy (see
Chapter 2 - 15: the hierarchy diagram).
Each ActiveX object has its own member function definition.
When the member functions are exposed, it makes the object
programmable by an ActiveX client. Three types of members can
be exposed for an object:
S
Methods
are actions that an object can perform. For exam-
ple, the
Document
object in your labeling software provides
a
Close
method that closes the current document.
S
Properties
are functions that access information about the
state of an object. The
Application
object’s
Visible
property
determines whether the labeling software is visible or not.
S
Events
are actions recognized by an object, such as clicking
the mouse or pressing a key. You can write code to respond
to such actions. In Automation, an event is a method that is
called, rather than implemented, by an object (see also
Chapter 1 - 11).
Your labeling software often works with several instances of an
object which together make up a
Collection object
. For
example, since your labeling software is a multiple-document
interface (MDI), it might have multiple documents. To provide an
easy way to access and program the documents, your labeling
software exposes an object named
Documents
, which refers to
all of the already opened document objects.
Documents
is a
collection object.
A Collection object lets you work as a group with the objects it
manage (see Chapter 1 - 9).
All the methods, properties and events are defined in
Chapter 2 - 17: Reference Guide.