FileMaker Extra: Designing Cross-PlatformFriendly Layouts

FileMaker Extra: Designing Cross-Platform “Friendly Layouts

One of the things that sets FileMaker apart from other database applications is that it runs on both Windows and Macintosh operating systems. You can even have a mixed platform of client machines. If you are developing a system that needs to run on both platforms, there are a few design considerations you'll need to keep in mind.

First, text blocks may be rendered slightly differently between platforms because of differences in the dots per inch (dpi) that each supports. Macintosh operating systems use 72 dpi, whereas Windows is built at 96 dpi. Font sizes are always described as 72nds of an inch regardless of platform, which means that a 12-point font takes up 12 pixels (12/72nds of 72) on a Macintosh monitor, but 16 pixels on a Windows monitor (12/72nds of 96). In either case, this represents 1/6th of an inch.

The problem is that graphics and other layout objects are set to be a precise number of pixels tall and wide. If, for instance, you have a text block or field on a layout that's set to be 72 pixels wide, you'd be able to see fewer characters in that space on Windows. To account for this, you should make text blocks and buttons slightly oversized so that you don't truncate characters on Windows.

Not all fonts available on one platform are supported on the other; platform-specific fonts should be avoided. Some fonts display different baselines on Mac and PC. Trebuchet, for example, is a particularly bad culprit. The text baseline determines where the "bottom" of a font appears within a text block. Different baselines may mean that letters that hang below the baseline (such as g, y, j, p) have their tails cut off. Verdana tends not to be so bad. The combination of font and field box size is tricky and you'll just have to experiment. 10-point Verdana with a 16-pixel field height tends to work well on both platforms, but it's a very wide font. Use Arial/Helvetica if you're pressed for space.

The other big cross-platform layout problem is the viewable size of your layouts. It's generally desirable to create layouts where users won't need to scroll to see important information. Different operating systems, even within a platform, may have different viewable layout areas, even at the same monitor resolutions . The problem is compounded by users who position their Dock or Start menu bar in different places. Windows XP tends to be the "piggiest" consumer of screen real estate and represents your lowest common denominator for a given resolution.

In the end, of course, the best advice when developing cross-platform applications is simply to test everything early in your development process on all operating systems that you plan to support.