Build fcitx-qimpanel based on qt4 default.
Build fcitx-qimpanel based on qt5 by Using the cmake command as follows:
 cmake -DQT_5=ON -DQT_4=OFF ../
How to Install fcitx-qimpanel in ubuntu + qt5:
 mkdir build; cd build
 sudo apt-get install cmake
 sudo apt-get install build-essential
 sudo apt-get install fcitx-libs-dev
 sudo apt-get install qtbase5-dev qtdeclarative5-dev qttools5-dev-tools qttools5-dev
 cmake ../
 make
 sudo make install
How to Install fcitx-qimpanel in ubuntu + qt4:
 mkdir build; cd build
 sudo apt-get install cmake
 sudo apt-get install build-essential
 sudo apt-get install fcitx-libs-dev
 sudo apt-get install libqt4-declarative libqt4-dev libqt4-dev-bin qt4-default qt4-dev-tools qt4-qmake
 cmake ../
 make
 sudo make install