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Appendix A: Building Dashboard Widgets

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In This Appendix

Introducing Dashboard

Profiting from widgets

Understanding widget technology

Introducing Dashcode

Building a widget in Dashcode

Widgets were introduced in 2005 in OS X 10.4 Tiger. Like iPhone apps, widgets offer users a simple, accessible benefit in a stylish wrapper. Some widgets provide unit or currency conversions or utilities such as clocks, calculators, and countdown timers. Others package entertainment — cartoons are a popular choice — or Web information, such as traffic reports or weather. And widget games are always popular.

Users continue to find widgets fascinating because they make it easy to customize a Mac with a unique collection of attractively packaged micro-applications.

The look and feel of widgets is based very loosely on Yahoo!'s Konfabulator project, which was formerly sold as a separate OS X application. Internally, widgets use JavaScript, HTML, and CSS, but include links to elements of Cocoa, and can be extended with plug-ins written in Objective-C.

Introducing Dashboard

Widgets load and run automatically within Dashboard — the widget manager application. Dashboard, shown in Figure A.1, runs permanently ...

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