install fcitx input method on ubuntu

The default scim input method doesn't work well with freemind on my computer, so I'd like to switch to fcitx. The fcitx package in ubuntu repository is an old version, and to install fcitx manually isn't very straightforward, so I make this post about how I managed to get it to work.

1. Download fcitx source code and extract.
2. Make sure all dependent libraries are installed:

sudo apt-get install libpango1.0-dev libcairo2-dev xorg-dev libtool gettext intltool

3. Run configure && make && make install
4. At this time, fcitx failed to run and gave following error:  fcitx: error while loading shared libraries: libfcitx-config.so.4: cannot open shared object file: No such file or directory. To fix it, create a symbol link in /usr/lib with this command:

sudo ln -s /usr/local/lib/libfcitx-config.so /usr/lib/libfcitx-config.so.4

5. Create /etc/X11/xinit/xinput.d/fcitx file with below content. Alternatively we can place them in ~/.profile.

XIM=fcitx
XIM_PROGRAM=/usr/local/bin/fcitx
XIM_ARGS=""
GTK_IM_MODULE=XIM
QT_IM_MODULE=XIM
DEPENDS="fcitx"

6. Edit /usr/lib/gtk-2.0/2.10.0/immodule-files.d/libgtk2.0-0.immodules file, change the line
"xim" "X Input Method" "gtk20" "/usr/share/locale" "ko:ja:th:zh"
to
"xim" "X Input Method" "gtk20" "/usr/share/locale" "en:ko:ja:th:zh"
7. Restart

To make fcitx more convenient to use, I run fcitx-config and change configurations below.

# Candidate Word Number
CandidateWordNumber=9
# Main Window Hide Mode
MainWindowHideMode=Auto
# Show Input Window After Trigger Input Mode
ShowInputWindowAfterTriggering=False
# Show Input Speed
ShowInputSpeed=False

Reference:
fcitx4.pdf