IBM X31 Debian Wheezy Trackpoint 小紅點的中鍵滾輪正確解法

在殺肉組合零件之後，第二部IBM X31也正式服役了。安裝了 Debian Wheezy XFCE + LXDE 桌面。碰到最困擾的問題在於XFCE / LXDE 桌面環境下，小紅點的中鍵滾輪模擬無法正確動作，找了一陣子，正確解法如下：

參考http://wiki.debian.org/InstallingDebianOn/Thinkpad/Trackpoint

To enable scrolling with the TrackPoint while holding down the middle mouse button, create a new file /etc/X11/xorg.conf.d/20-thinkpad.conf with the following content:

 Section "InputClass"
     Identifier "Trackpoint Wheel Emulation"
     MatchProduct       "TPPS/2 IBM TrackPoint|DualPoint Stick|Synaptics Inc. Composite TouchPad / TrackPoint|ThinkPad USB Keyboard with TrackPoint|USB Trackpoint pointing device"
     MatchDevicePath    "/dev/input/event*"
     Option             "EmulateWheel"          "true"
     Option             "EmulateWheelButton"    "2"
     Option             "Emulate3Buttons"       "false"
     Option             "XAxisMapping"          "6 7"
     Option             "YAxisMapping"          "4 5"
 EndSection

(Taken from https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X120e#TrackPoint_Scrolling_.28wheel_emulation.29 )