How to have middle button function in Macbook trackpad for use with Eagle
Autor: Jonathan Araujo | Publicado: 2011-11-12T14:34:00-02:00

Hello,

This post is going to be in English again :-)

I recently got a Macbook Air and after installing Eagle ( a software for electronics design) I immediately found the lack of middle click to 'pan' around the circuit or PCB when using the trackpad

After a long research I couldn't find any viable solution, so I was on my own and had to hack ( it was not a bad thing at all&nbsp; :-D )

The best solution so far is using the excellent software called KeyRemap4MacBook that can be downloaded here: http://pqrs.org/macosx/keyremap4macbook/. Despite the name, it can also handle mouse clicks and some multi-touch actions.&nbsp; The software can 'change' the behavior of keys and buttons to another ones. So, the idea is to emulate the middle button click some way.


Using it - the simple way

After installing, go System Preferences and go to Other and run the KeyRemap4MacBook.&nbsp; Next, go to the 'Change Key' tab.

There's tons of predefined remaps. Three of them can suit the needs for Eagle use by default, as follows. You can use the search box to filter for all 'middleclick' remaps.

You can choose any of the above ( or all, if you want). After checking, you can try it in Eagle, clicking in trackpad while keeping the Control, Fn&nbsp; or Right Command key pressed, depending on what you choose.

It should do the job, but if you are like me that like the 'tap' way,&nbsp; it won't work, unless you 'hard click' in trackpad.

Using it - the better way

Luckly, KeyRemap4MacBook is very customizable.&nbsp; To make it better, I have created my own remaps that will only work in Eagle to avoid messing up with other software. You can hack it and let it work for all software if you wish, it's pretty easy. Just edit the XML file provided here.

In the 'Misc and Uninstall' tab, click 'Open private.xml'. Open it in Text editor and paste the content of my private.xml file* and then 'Reload XML' at the 'Change Key' tab.

* Download link is at top-right of Google Docs page.

Now you should see an 'Eagle software' entry at the beginning. If not, check if your private.xml file.

I like to use Tab because it's almost useless in Eagle, and if you need it you still can use Fn+Tab. You miss Alt-Tab of the system as draw back :-(
If you use Shift you still can use the right Shift as usual, so it's a another nice option. 


Using it - the nice and harder way

Another interesting choice it to use the multi-touch functionality&nbsp; and have a 3 finger click to have a middle click.

You must have private.xml changed as above first. Also, make sure you have 'Drag with three fingers'* checked in Trackpad section of System preferences.

Then, go to KeyRemap4MacBook &nbsp; 'Misc and Uninstall' tab and click 'Launch multi-touch extension'.

Check the last option only and past the following: private.threefingersclick2middleclick


To test, go to Eagle and Drag with 3 fingers. The middle click is locked and you can pan just sliding with only one finger then. To unlock, press any key without touching the trackpad.
I don't know why it locks, but it's nice anyway.


If you like this post, please comment.&nbsp; Let me know if you have some questions of may help some way.

Good luck!

Jonathan