qt android

Create a cross-platform application with Qt

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Qt 5.4 for Android package

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Qt 5.4 for Android package

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• Supported for Android versions 2.3.3 (API 10) or later

• Qt 5 • C++, Qt Quick

• Sensors reading, and multimedia features are fully supported

• Network, database, …

• Qt Creator IDE : Powerful cross‐platform integrated development environment including UI designer tools

• Tools and toolchains : Embedded toolchains for ARMV7 and x86 platforms, QtLinguist, …




Installation requirements

• Some external tools needed

• The Android SDK tools

• The Android NDK

• Apache Ant v1.8 or later

• JDK v6 or later





• Qt for android

• Prebuilt binaries for Linux and windows

• http://qt-project.org/downloads

• Qtcreator:

• Support QtGUI, QtQUICK1/2, Console

• Manage the “Kits”

• Setup location of the android SDK+NDK

• Start AVD

• Deploy application

http://qt-project.org/downloads








• Qt for android




Supported Items

• Qt Widgets and QML Applications

• QML media player functionality in Qt Multimedia

• A set of sensors in Qt Sensors

• Deploying app to a device from Qt Creator

• Complete support of Qt components in Qt 5.4 release




Compatibility map : Qt

Sensors

Feature Android

Accelerometer

Altimeter

Ambient Light Sensor

Ambient Temperature Sensor

Compass

Gyroscope

Holster Sensor

IR Proximity Sensor

Light Sensor

Magnetometer

Orientation Sensor

Pressure Sensor

Proximity Sensor

Rotation Sensor

Tap Sensor

Tilt Sensor

Sensor Gestures




Deployment

Three methods to deploy Qt applications on Android:

• Bundle Qt libraries and files into the apk • Provide stand-alone and distributable application package

• Using Ministro • Minimize the size of the APK by sharing Qt libraries across all Qt based

applications

• Debugging • More convenient when testing an application on a device physically

connected to the development machine




Deployment

Three methods to deploy Qt applications on Android:

• Projects

– <Choose you kit>

• Deploy configurations




Deployment

Using ministro:

• Available on Google Play

• The application will ask ministro for Qt components

• Ministro can download required components: • If they are not installed

• If newer versions exist

• GPLv3+ license for the APK

• BSD License for the API

• Install LGPLv2.1 / GPLv3 Qt libraries

• Make Qt libraries available to all Qt based applications




Deployment

Deployed by qtcreator or in the APK

• Select the Kit

• Make sure that an AVD is declared (sdk/tools/android avd)

• Running the project will start the AVD deploy the libaries and run the application using adb push and adb install

• Deploy in the APK for production

• Deploy to device for debugging (platform dev)




Deployment

On an Android emulator On a real Android device

On a Embedded Android device




Project architecture

• Qt base project

• Project file configuration .pro

• C++ sources and headers .cpp/.h

• QML, javascript .qml/.js





• Android activity

• Java files

• Entry point of the application

• Load Qt application and execute native code





• Resource files • Contains android specific files





• AndroidManifest.xml • Provide meta-information about the app





• QtApplication.java – Qapplication for android

– Java Application class that handle global state

– Uses the Java reflection API

• QtActivity.java – Only one activity used to render Qt: Qt Platform Abstraction API

(QPA) • Graphics

• Events propagations

• Clipboard

• …

– Interface with ministro




Qt Quick : Design

sophisticated GUI

• Perfectly fitted for Android and mobile devices • Gestures, animations

• Network transparent, sensors

• Design oriented • GUI conception accessible to designers

• Simple components to create your own UI

• Completely separate UI and logic




Qt Quick : Design

sophisticated GUI

• Completely separate UI and logic • Allows switching UI at runtime

• Access C++ through bindings and functions • C++ and UI data automatically synchronized

Development

User interface .qml

Source code .cpp/.h

Application

Scripts .js C++ Data

Objects

User interface .qml .

Scripts .js

Execution




How to use Android API ?

• Work with JNI

• Call OS specific functions

• Use functionalities not supported yet by Qt

• Communicate with others applications





• On C++ side • JNI is loaded when application starts

• We need to → Get the JNI environment

→ Get a pointer on Java Virtual Machine





• On Java side → Implement Java methods




New features in Qt 5.4

• Fully support development of Qt applications for Android

• New module : Qt Android Extras for integration with native code on Android

• Webkit is not supported, but all the following modules are supported




New features in Qt 5.4

• QQuickWidget is now supported, to easily integrate a QQuick GUI into a widget based application

• Qt Positioning : Android supports position and satellite updates

• Qt Bluetooth allows connecting to remote devices through a RFCOMM channel using the Serial Port Profile (SPP)

• Qt Network module with a new bearer plugin for Android

• Qt Purchasing API is currently supported for Android (Google Play) for monetization




Native Android Look

• Qt helps developers by providing native Android styling of the graphical user interface, matching Android buttons and components appearance and behavior.

• The new look and feel of Android 5.0, Material design, is only partially supported.




Licenses

• Qt Company proposes a dual licensing :

– Qt Open Source

– Qt commercial : full rights to modify source code, Qt support Help desk, Qt & QtQuick new components, additional tools, Boot To Qt (Enterprise), Embedded platforms support (Enterprise), applications’ distribution through application stores (Indie Mobile) and Qt Cloud Services




Publication on the PlayStore

• First store for distributing Android applications

• With Indie Mobile license, it is possible to distribute applications via whatever third party application store you wish.

• Steps :

– Sign the .apk

– Publish the application on Google Play

– Monetize it




Speedometer sample

application

• Demo




Conclusion

• Qt offers new ways for developing Android applications

• It is a good alternative to Java & HTML cross platform frameworks

• It continues to evolve

• Qt 5.5 has more planned and should be released at the end of April 2015.

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