Chapter 1

Overview of ActiveX Designers

A designer is a top-level software component that includes a dedicated design environment. Built into a running program, a designer provides features that allow users to customize their applications. The Forms class included with Microsoft^® Visual Basic^® is one type of designer. ActiveX™ designers are another.

This chapter provides an overview of ActiveX designer features and technologies, including the following topics:

• ActiveX Designers and the Component Object Model
  
  
• Components of an ActiveX Designer
  
  
• Interfaces Provided by ActiveX Designers
  
  
• Where to Go for More Information

ActiveX designers are based on the Component Object Model (COM). An ActiveX designer is an ActiveX component that has a programmable interface and a dedicated visual designer. Loaded into a host's development environment, an ActiveX designer allows end users to customize objects for run-time use. The customized objects can then be registered and made public, as in the following examples:

• The supplier of a large MIS application might develop an ActiveX designer that contains forms and controls unique to its databases. Visual Basic database programmers at customer sites can then use the ActiveX designer to create local applications that access the database and perform specific query and update tasks.
  
  
• An HTML page designer could allow a user to design a web page in the Visual Basic IDE (Integrated Development Environment); the created object then runs in the Internet Explorer environment.
  
  
• A simple ActiveX designer could allow users to add their own properties to an ActiveX control.

Much of the technology needed for ActiveX designers exists in COM, Automation, and ActiveX controls. The ActiveX Designer Programmer's Reference describes software and interfaces especially for designers and discusses how to integrate existing technologies into an ActiveX designer.