How can I set the path for a QCompleter using a QFileSystemModel?

How can I set the path for a QCompleter using a QFileSystemModel?

References

Reference NO 1

http://stackoverflow.com/questions/15197660/how-can-i-set-the-path-for-a-qcompleter-using-a-qfilesystemmodel

Reference NO 2

http://qt-project.org/forums/viewthread/22511

Reference NO 3

http://www.qtcentre.org/threads/54378-QCompleter-with-QFileSystemModel-not-always-popping-up

Reference NO 4

http://lists.qt.nokia.com/public/qt-interest/2011-July/034757.html

Reference NO 5

http://srinikom.github.io/pyside-docs/PySide/QtGui/QCompleter.html

Reference NO 6

https://qt.gitorious.org/qt/qt/blobs/7101a3fafb40cacb855ee07036ce4baacc5d202b/src/gui/util/qcompleter.cpp

Reference NO 7

http://blog.qt.digia.com/blog/2010/01/08/qdirmodel-is-now-obsolete-qfilesystemmodel-is-taking-the-job/

Reference NO 8

http://nullege.com/codes/search/PyQt4.QtGui.QFileSystemModel