Volume Number: 14 (1998)
Issue Number: 7
Column Tag: MacTech Online
by Jeff Clites <online@mactech.com>
By virtue of the Mac's user interface, all Macintosh applications are graphical in nature, whether or not they have graphics as their actual subject matter. Some would go so far as to argue that on a Mac the interface is the whole point. So even if you are not developing the next Doom or Photoshop, you still have to think about the way things look on screen, and a well-designed interface can set a successful product apart from the competition. The actual appearance is only one aspect of effective interface design, but it is an important one, because it shapes a user's first impression of your application.
Fortunately, there are a wealth of shareware products available to help you tweak your interface until it is just how you want it, and to help you inspect the interfaces of other applications to see what they did right (or wrong). In the early days of Apple's Grayscale Appearance, designers spent no end of time wondering what exact shade of gray certain applications used to achieve their subtle three-dimensional effect. It's a simple question, but a difficult one to answer without the right tool. There are several products which fill the need nicely, allowing you to view an arbitrary region of the screen at magnification, and determine the color of individual pixels. Check out ColorFinder, Color Picker Pro, ColorSieve, Coloristic, and Pixel Spy, and decide for yourself which you like best.
Screen Ruler is one of those unique applications which makes you wonder, "why didn't I think of that?" It places a ruler on the screen, allowing you to measure distances down to the pixel. So if you have trouble remembering how wide a scroll bar is, you can just whip out Screen Ruler and see for yourself, and you can avoid eye strain by using it in conjunction with one of the previously mentioned magnifying glasses.
Although it is less often used in the interface itself, antialiasing can be an effective way to lend a more polished look to your application's interface elements, or to its splash screen or About box. Two excellent examples are the About box of Aaron Giles' popular JPEGView image viewer and the button and text-field labels of Trygve Isaacson's Hex Wrench programmer's calculator, both of which use antialiasing of grayscale text. (And of course, these are useful tools to have around in their own right.)
Antialiasing can be done on-the-fly, and there was an article in January 1997's MacTech explaining how to do this using QuickDraw's CopyBits routine. But you can also create antialiased images and text with an image editor, and use them within your application as you would any other PICT resource. Which technique is best depends on your situation, but the latter approach if often appropriate and has the advantage of allowing you to use nonstandard fonts without requiring the user to have them installed. An excellent shareware application for this sort of thing is Thorsten Lemke's GraphicConverter.
When it comes time to put the finishing touches on your new application, you just have to have a cool icon. If you'd like to use a tool which is a little more powerful than ResEdit, take a look at Icon Machine -- it's full of nifty features.
With the advent of QuickTime, programmers don't have to worry about the details of various file formats just to get an image onto the screen. Even so, sometimes you do need to know what makes a JPEG a JPEG and a TIFF a TIFF, and how to handle them on your own. O'Reilly maintains the Graphical Data Standards and File Formats page as a companion to their book Encyclopedia of Graphics File Formats, and it has links to information on a wide range of image formats. For things not covered here, head over to Wotsit's File Format Collection, which has a massive assemblage of information on just about any file format you are likely to encounter, including image formats but not limited to them.
For specific information on JPEG (the Joint Photographic Experts Group format), the official JPEG home page has a collection of links to useful information. For TIFF (the Tagged Image File Format), there is the Unofficial TIFF Home Page. Finally, there is PNG (the Portable Network Graphics format), which is gaining in popularity as a free replacement for the proprietary GIF format for lossless compression. Its home page is full of personality, giving the history of PNG as well as listing its strengths and spelling out the technical details. Macintosh versions of code to work with each of these formats is available on Jack Jansen's page.
These and other links are available from the MacTech Online web pages at www.mactech.com/online/.
