don@BRILLIG.UMD.EDU (Don Hopkins) (04/13/87)
By entering text with a "thermometer", I meant to make a metaphor comparing the columns of letters in a standardized test to a vertical choice or valuator, like a pull down menu, a virtual thermometer, a scroll bar, or the volume control on the Mac control panel; not the real temperature-measuring kind, of course. What I mean to point out is that widgets and applications should try to use input devices that are as abstract as possible, because by avoiding dependencies on such things as keyboard configuration (certian shift and function keys, keys being adjacent, key up events), or the number of buttons on a mouse, you make it much more likely that your software will inducing the minimum amount of pain, agony, and suffering, while fitting right into vastly different hardware configurations. Try not to depend on the semantics of particular input devices. For example, a touch screen will only register a position when it's being touched, so unlike a mouse, you can't track its position when it's not being pressed. And you can warp a mouse, but you can't warp a finger. -Don