2. Outline
• What is Qt ?
• What is Qml?
• Qml Elements
• Qt creator
• Qt on Android
3. What is Qt ?
• Cross-platform GUI application framework
• Written in C++
• Open Source
• Qt modules: Qt Core, Qt GUI, Qt QML, Qt Quick, Qt
Network, Qt Multimedia, Qt WebKit, Qt SQL …
• Software developed by Qt
– Perforce , tesla , VLC , google earth, Mathematica,
jewelrybox …
4. What is Qml ?
• Qt Meta Language
• JavaScript-based, declarative language for
designing user interface–centric app
• Support by QtQuick (the standard library for
writing QML applications)
• Mainly for mobile app
• Qml element easily to be extended by javascript
and C++ class
• Qml can use various qt modules
5. Qt Elements
• Item– basic element
• Rectangular – inherit from items
• Component --encapsulated QML types
• Animation
• Model --contains the data and its structure
• Delegate--dictates how the data should appear in the view
• View--a container that displays the data
– Pathview
– Grid view
– List view
6. Qt creator
• IDE
• Layout
• Example :
– calqlatr (java script)
– Calendar (c++)
7. QML on Android
• Support for native android style with Qt Quick Controls ,not
yet included material design
– http://doc.qt.io/qt-5/android-support.html
– http://doc.qt.io/qt-5/qtquickcontrols-
platformnotes.html#android-style
• Support most of Qt modules: multimedia , sensor reading,
GPS , bluetooth…
– http://doc.qt.io/qt-5/examples-android.html
• Develop on Qt creator
8. Qt Android Extras
• The way to call the android java api
• Example : qt notifier
http://doc.qt.io/qt-5/qtandroidextras-
notification-notificationclient-cpp.html
• Qt thread & Android thread
– http://www.kdab.com/qt-android-episode-7/
9. Pros
• Cross-platform
• powerful UI libraries
• IDE: Qt Creator
• Native-look
• Performance is the same with (maybe better than)
native app
– Qt Core is written in high performance C++
– Utilize hardware acceleration
– http://stackoverflow.com/questions/22460127/how-slow-or-fast-is-qt-
mobile-for-android
– http://www.developereconomics.com/cross-platform-apps-qt-vs-
html5/
– http://v-play.net/2014/10/qt-vs-html5-cross-platform-apps/
10. cons
• Size is large
– 35MB for hello world
– http://achipa.blogspot.tw/2014/11/native-ui-in-
qt-on-android-without.html
• Need to compile QMl
• Licensing is confusing
– https://blog.qt.io/blog/2009/11/30/qt-making-
the-right-licensing-decision/
