Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.
- Create BookmarkCreate Bookmark
- Create Note or TagCreate Note or Tag
- DownloadDownload
- PrintPrint
22. Accessibility > Broadcasting Updates
Broadcasting Updates
Your application should post notifications to let the VoiceOver accessibility system know about on-screen element changes outside of direct user interaction:
• When you add or remove a GUI element. The UIAccessibilityLayoutChangedNotification tells gives the VoiceOver accessibility system a heads up about those changes.
• Applications can post a UIAccessibilityPageScrolledNotification after completing a scroll action. The notification’s object should contain a description of the new scroll position (e.g., “Page 5 of 17” or “Tab 2 of 4”).
• When the zoomed frame changes, send a UIAccessibilityZoomFocusChanged notification. Include a user dictionary with type, frame, and view parameters. These parameters specify the type of zoom that has taken place, the currently zoomed frame (in screen coordinates), and the view that contains the zoomed frame.