Legacy Document

Inside Macintosh: Macintosh Toolbox Essentials /

Chapter 5 - Control Manager / Introduction to Controls

Buttons

Buttons appear on the screen as rounded rectangles with a title centered inside. When the user clicks a button, your application should perform the action described by the button title. Typically, buttons allow the user to perform actions instantaneously--for example, completing the operations defined by a dialog box or acknowledging an error message in an alert box.

Make your buttons large enough to surround their titles. In every window or dialog box in which you display buttons, you should designate one button as the default button by drawing a thick black outline around it (as shown in Figure 5-2). Your application should respond to key-down events involving the Enter and Return keys as if the user had clicked the default button. (In your alert boxes, the Dialog Manager automatically outlines the default button; you must outline the default button in your dialog boxes.)

Figure 5-2 A default button

You normally use buttons in alert boxes and dialog boxes. See the chapter "Dialog Manager" for additional details about where to display buttons, what to title them, how to respond to events involving them, and how to draw an outline around them.