Appendix A: Building Dashboard Widgets
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 ...
