Inside Macintosh: More Macintosh Toolbox /

Chapter 8 - Control Panels

This chapter describes how to develop a control panel to control the settings of systemwide features and how to create an extension for the standard Monitors control panel.

Create a control panel if you want to provide users with the ability to set preferences for global values or systemwide features. Some of the standard control panels allow users to change the speaker volume, set the date and time, and select a different desktop pattern. Although you must not develop control panels to replace the standard ones, you can create additional control panels for any features that meet the stipulations for control panels. If the feature that you want to implement as a control panel is complex or if its interface requires menu items and multiple, layered dialog boxes, you should create a small application instead of a control panel.

If you are a manufacturer of a video device, you can extend the standard Monitors control panel to include items that give users a simple way to control the features of your device. To do this, read the sections in this chapter that describe how to create an extension to the Monitors control panel. The standard Monitors control panel lets the user define the monitor's display of colors and, if more than one monitor is connected to the system, the relative position of each monitor. The Monitors control panel manages any extensions to it that you create.

To use this chapter, you should be familiar with how to create 'BNDL', 'ICN#', 'FREF', signature, and 'DITL' resources as described in the chapters "Finder Interface" and "Dialog Manager" of Inside Macintosh: Macintosh Toolbox Essentials. You should also understand how to handle events and change settings of controls, as explained in the chapters "Event Manager" and "Control Manager" of Inside Macintosh: Macintosh Toolbox Essentials.

The Finder, which performs a number of services for your control panel, uses the Dialog Manager to display your control panel's dialog box. In turn, the Dialog Manager uses the Control Manager to create and display buttons, radio buttons, checkboxes, and pop-up menus. Your control panel needs to make these controls active and inactive in response to messages from the Finder. If you include editable text items in your control panel, the Dialog Manager uses TextEdit to handle associated editing tasks. (For general information on TextEdit, see the chapter "TextEdit" in Inside Macintosh: Text.)

This chapter provides a general introduction to control panels and introduces the Monitors control panel. It then describes how to

• define the user interface for a control panel
• create the resources for a control panel, including the rectangle and item list resources
• specify the font for your control panel's text
• write a control panel function
• write an extension for the Monitors control panel

---

Chapter Contents

About Control Panels

Control Panels

A Control Panel's Resources

The Finder's Interaction With Control Panels

Control Panels and System Extensions

About User Documentation for Control Panels

The Monitors Control Panel and Extensions to It

Creating Control Panel Files

Defining the User Interface for a Control Panel

Creating a Control Panel's Resources

Resource IDs for Control Panels

Defining the Control Panel Rectangles

Creating the Item List Resource

Defining the Icon for a Control Panel

Specifying the Machine Resource

Creating the File Reference, Bundle, and Signature Resources

Providing Additional Resources for a Control Panel

Specifying the Font of Text in a Control Panel

Creating a Font Information Resource

Defining Text in a Control Panel as User Items

Writing a Control Panel Function

Determining If a Control Panel Can Run on the Current System

Initializing the Control Panel Items and Allocating Storage

Responding to Activate Events

Responding to Keyboard Events

Responding to Mouse Events

Responding to Update Events

Handling Text Defined as User Items

Responding to Null Events

Responding to the User Closing the Control Panel

Handling Edit Menu Commands

Handling Errors

Creating an Extension for the Monitors Control Panel

Designing the User Interface for a Monitors Extension

Creating the Required Resources for a Monitors Extension

Creating a Card Resource for a Monitors Extension

Defining a Rectangle for a Monitors Extension

Creating an Item List Resource for a Monitors Extension

Creating the Monitor Code Resource

Supplying Optional Resources for a Monitors Extension

Specifying an Icon for the Options Dialog Box

Specifying Version Information

Providing an Alternative Name for a Video Card

Supplying Gamma Table Resources

Creating File Reference, Bundle, and Signature Resources

Including a System Extension Resource

Writing a Monitors Extension Function

Handling the Startup Message

Performing Initialization

Responding to a Click in the OK Button

Responding to a Cancel Request

Handling Mouse Events for a Monitors Extension

Handling Keyboard Events

Including Another Control Panel Definition in a Monitors Extension File

Control Panels Reference

Application-Defined Routines

Control Device Functions

Monitors Extension Functions

Resources

The Machine Resource

The Rectangle Positions Resource

The Font Information Resource

The Control Device Function Code Resource

The Card Resource

The Monitor Code Resource

The Rectangle Resource

Summary of Control Panels

Pascal Summary

Constants

Application-Defined Routines

Control Device Functions

Monitors Extension Functions

C Summary

Constants

Application-Defined Routines

Control Device Functions

Monitors Extension Functions