Datasheet

focus on commonly available technologies and concepts. It is difficult to gain access to features unique to
Mac OS X, such as the power of CoreGraphics, through Java’s application frameworks, because those
features are not available on all Java systems. Because this book focuses on technologies specific to Mac
OS X, we will not examine Java in further detail.
Apple Human Interface Guidelines
All Mac OS X programs share a specific look and feel that makes them instantly recognizable as Mac
OS X programs. This creates the illusion that all the applications on your system were designed to work
together — even though your applications may have been designed by different people, all with differ-
ent interests. Once you learn how to use one application, you have a pretty good idea of how to use all
applications.
Apple provides a document, called the Apple Human Interface Guidelines, that spells out how Mac OS
X applications should look and behave. Applications written against one of Mac OS X’s application
frameworks start with a bit of an advantage: all the user interface elements provided by these frame-
works meet the specifications in the Apple Human Interface Guidelines. All the controls in Figure 1-7 are
drawn using the Cocoa application framework; notice that they all look like Mac OS X controls.
Figure 1-7
Unfortunately, simply using the right controls isn’t enough to make an Aqua-compliant interface. A large
part of user interface design is in collecting and organizing controls so they make sense. The Apple
Human Interface Guidelines provide metrics for how far apart related controls and groups of controls
should be and where certain kinds of controls should go. The Aqua guidelines specify specific fonts and
font sizes for UI elements. It also specifies when certain features are appropriate, such as default buttons,
hierarchical menu items, and so on. Figure 1-8 illustrates the same controls from Figure 1-7, laid out in
compliance with the Apple Human Interface Guidelines; note it looks much cleaner.
Figure 1-8
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