Teaching the Trackpad New Tricks?

An anonymous reader asks: "I'm seriously considering buying a PowerBook. The design is gorgeous and OS X will give me a Unix-based operating system without having to sacrifice main-stream comercial applications. What's holding me back? The trackpad. I'm a fan of the ThinkPad-style joystick, but my Dell laptop came with touchpad drivers that provide useful features like the ability to scroll by sliding your finger along the edge of the pad. That was enough to make me switch to the touchpad on the Dell, but, I can't find anything similar for the PowerBook. I found references to Overdrive, but it appears to only work with USB devices. Are there any other drivers out there that add more functionality to the trackpad? If not, is that because no one has done it yet, or is it because the APIs do not exist to do such a thing? Thanks."

Comments

Not gonna happen

[MasterVidBoi]

About a month ago I thought about writing a shareware product that would do things like that (scroll area on the side of the pad). After a lot of research, I've concluded that it can't be done...

Unless a lot of secret Apple documentation suddenly falls into my lap... if you have such secret documentation, please don't hesitate to send it to me ;)

A little background:
The Trackpad on apple laptops (as well as the keyboard), are pseudo-ADB devices. Still. Even after ADB was supposted to be dead years ago.
I say pseduo because Apple employees claim that the hardware really isn't ADB, but it acts like one as far as the OS is concerned (at the mouse/trackpad driver level. lower down, the situation may be different).

Because of this, from the level of the ADB Mouse Driver, it looks and behaves exactly like those old Apple Extended mice (except for a few additions, such as tap-click, drag, etc). The standard ADB Extended Mouse Protocol, (as documeneted in the Apple Technote 'Space Aliens Ate My Mouse'), only reports relative movements of the pointer, as a normal mouse would.

There is no mechanism for getting the absolute location of the users finger, rather than the relative movement. Without that, you can't remap part of the trackpad to be a scroll area.

Use the Command key

[Decimal Dave]

A good substitute for the simulated scroll wheel feature is to hold the Command key and then drag with the mouse/trackpad. In some applications this will allow the cursor to "grab" the page to scroll both vertically and horizontally. I use it quite a bit in IE and the Finder (under OS 9, haven't tried it with OS X). Unfortunately, many applications don't work like this.