Qt 5.4 CMake Manual

This manual details the specifics of how to use Qt 5 with CMake. The minimum version required to use Qt5 is CMake 2.8.3, but 2.8.11 is recommended.

http://doc.qt.io/qt-5/cmake-manual.html

QFontMetrics Class

http://doc.qt.io/qt-5/qfontmetrics.html
http://doc.qt.io/qt-5/qfont.html

https://www.google.com.tw/search?q=QFontMetrics&lr=lang_zh-CN%7Clang_zh-TW&es_sm=122&biw=1920&bih=955&tbs=lr:lang_1zh-CN%7Clang_1zh-TW&source=lnms&tbm=isch&sa=X&ei=FiDsVJfRCsacugTskILYDQ&ved=0CAsQ_AUoBA

https://developer.apple.com/library/mac/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png