C H A P T E R 1 5

Controls

Gradient Button Implementation

Gradient buttons are available in Interface Builder. To create one using Application Kit programming interfaces, use the setBezelStyle: method of NSButtonCell with NSSmallSquareBezelStyle as the argument.

The Help Button

The Helpbutton opens a window that displays a specific help page appropriate for the context of the button. Don’t create a custom button to do this; use the standard Help button, which contains the Mac OS X question mark graphic.

In dialogs (including preferences windows) and drawers, the Help button can be located in either the lower-left or lower-right corner. In a dialog that includes OK and Cancel buttons (or other buttons used to dismiss the dialog), the Help button should be in the lower-left corner, vertically aligned with the buttons. In a dialog that does not include OK and Cancel buttons, such as a preferences window, the Help button should be in the lower-right corner. Figure 15-16 shows an example of a preferences pane that includes a Help button.

Figure 15-16 Help button in a preferences pane

Help button

For information on providing help in your application, see “User Assistance” (page 80).

The standard Help button is 20 pixels in diameter and should be placed at least 12 pixels from other interface elements. See “A Simple Preferences Dialog” (page 337) for an example of Help button placement in a dialog.

268 Buttons

2008-06-09 | © 1992, 2001-2003, 2008 Apple Inc. All Rights Reserved.