Inside Macintosh: More Macintosh Toolbox /

Chapter 8 - Control Panels

Creating an Extension for the Monitors Control Panel

This section describes how to create an extension for the Monitors control panel. A monitors extension typically adds controls to the Options dialog box so that the user can set values for one or more features of a video card.

A monitors extension consists of a file of type 'cdev' that contains the resources for a monitors extension, including a code resource of type 'mntr'. This code resource, called a monitors extension function, communicates with the Monitors control panel, responding to requests from the Monitors control panel to handle events or perform actions. This section begins with a discussion of the interface components of a monitors extension. Then it describes how to

• create resources for your monitors extension, including how to define
  • a card resource to identify your monitors extension and display the name of your video card at the top of the Options dialog box
  • a rectangle resource to define the area in which to display your video card's controls
  • an item list resource to define additional items for display in the Options dialog box

• create and supply optional resources for your monitors extension
• write a monitors extension function

Before you develop an extension for the Monitors control panel, consider these three important points:

• You should develop a monitors extension only if you are the manufacturer of the video card for which you are providing the feature or features whose values the user can control.
• There can be only one extension to the Monitors control panel for each video card. Apple Computer, Inc., reserves the right to supply monitors extensions for its own video cards.
• If the features that you want to implement require an extensive or complex set of controls--for example, if you need to use nested dialog boxes--you should probably write a small application rather than an extension to the Monitors control panel.

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Subtopics

Designing the User Interface for a Monitors Extension

Creating the Required Resources for a Monitors Extension

Supplying Optional Resources for a Monitors Extension

Writing a Monitors Extension Function

Including Another Control Panel Definition in a Monitors Extension File