Android & iOS on the edge of Qt and Java/Objective-C Maciej - - PowerPoint PPT Presentation

Android & iOS – on the edge of Qt and Java/Objective-C

Maciej Węglarczyk

Android & iOS – on the edge of Qt and Java/Objective-C About me

• Cracow, Poland
• Graduated from AGH-UST with MSc in CS
• 6+ Qt years
• Game industry
• Ganymede Ltd. (3 years+)
• Android & iOS lead

The purpose of this talk

• Explain if / why one needs to write code beyond Qt
• Show what cannot be done with only Qt
• Give a taste of the way to communicate with native environments
• Give a brief overview how Qt is integrated with Android & iOS

Android & iOS – on the edge of Qt and Java/Objective-C

Agenda

• Reasons of extending Qt app with native code
• Needed tools
• Mixing Qt with Java/Objective-C
• Adding 3rd party libraries
• Modifying application entry point

Android & iOS – on the edge of Qt and Java/Objective-C

Beyond Qt “It's a dangerous business, Frodo, going out of your door”

Bilbo Baggins

Android & iOS – on the edge of Qt and Java/Objective-C

EXTENDING? WHY?

Android & iOS – on the edge of Qt and Java/Objective-C

Importance of rich features

• Over 1,000,000 apps available in Google Play and Apple AppStore each
• Very demanding users
• Different ways of monetization
• Chances of being featured
• Increasing user engagement
• Virality

Android & iOS – on the edge of Qt and Java/Objective-C

Native integration - it's actually nothing new

• Qt Windows Extras, Qt Mac Extras, Qt X11 Extras
• Mobile OSes are evolving faster
• The problem is similar

Android & iOS – on the edge of Qt and Java/Objective-C

Where to start?

• First of all – know what you want and why
• Check if Qt supports it
• If not, check if it hasn't been done already by someone else...
• ...or if it couldn't be done by someone else in near future. :)

Android & iOS – on the edge of Qt and Java/Objective-C

What's not possible with Qt (at least for now)

• Notifications (push, rich)
• SMS API
• Lock screen widgets
• Home screen widgets
• Google / Apple API
• Maps
• Game Services / Center
• Calendar
• ...
• Alarms
• Communication with other apps
• Many useful 3rd party integrations
• Facebook Connect
• Google Analytics
• Monetization libs (i.e. Chartboost)
• ...

Android & iOS – on the edge of Qt and Java/Objective-C

Required tools Android & iOS – on the edge of Qt and Java/Objective-C

Android

• QtCreator
• Some IDE for Java, i.e. Eclipse
• Android SDK & NDK
• Ant
• Some devices

(emulator is still rather slow and sometimes unreliable)

iOS

• QtCreator
• Xcode
• Apple Developer Program Account
• Xcode Command Line Tools
• Simulator is OK

(devices are better, though)

Useful tips

• Compile Output panel is much much more informative than Issues panel
• Android: QtCreator's Build command builds only Qt code, not Java yet
• Android: turn on the androiddeployqt's verbose option

Android & iOS – on the edge of Qt and Java/Objective-C

Basic Android / iOS projects

• Just take any of Qt's examples for given platform
• Compile and run it from QtCreator
• That's it

Android & iOS – on the edge of Qt and Java/Objective-C

ADDING NATIVE CODE

Android & iOS – on the edge of Qt and Java/Objective-C

Adding native code – Android

• JNI – Java Native Interface
• Encapsulated into Qt's androidextras module
• Containing a couple of useful classes and a namespace QtAndroid

QT += androidextras QAndroidActivityResultReceiver QAndroidJniEnvironment QAndroidJniObject

Android & iOS – on the edge of Qt and Java/Objective-C

Adding native code – Android

• Both directions possible:
• C++ -> Java
• Java -> C++

<Example>

https://github.com/FenixVoltres/QtAndroidCpp2Java https://github.com/FenixVoltres/QtAndroidJava2Cpp

Android & iOS – on the edge of Qt and Java/Objective-C

Adding native code – iOS

It's very simple:

• Create some C++ class with normal header
• Use Objective-C in bodies of declared methods.
• That's all!

Android & iOS – on the edge of Qt and Java/Objective-C

Adding native code – iOS

• Following example taken from Richard Moe Gustavsen's

talk on Qt for iOS from last year Qt DD 13

<Example>

https://github.com/richardmg/qtdd13_qmlapp

Android & iOS – on the edge of Qt and Java/Objective-C

How about Swift?

• C++ code can’t be executed from Swift directly
• Objective-C wrapper needed

Swift -> Objective-C++ -> Qt

Android & iOS – on the edge of Qt and Java/Objective-C

ADDING NATIVE LIBRARIES

Android & iOS – on the edge of Qt and Java/Objective-C

Adding native libraries – Android

• Make sure you have defined ANDROID_PACKAGE_SOURCE_DIR variable in .pro file
• Add libs folder inside and put there all jars you want
• $PROJECT
• android-sources
• libs
• <put your jar here>

<Example>

https://github.com/FenixVoltres/QtAndroidNativeLib

Android & iOS – on the edge of Qt and Java/Objective-C

Adding native libraries – iOS

Even simpler:

LIBS += -F/path/to/frameworks/folder LIBS += -framework StoreKit Android & iOS – on the edge of Qt and Java/Objective-C

MODYFYING ENTRY POINT

Android & iOS – on the edge of Qt and Java/Objective-C

Why one would modify an entry point?

• Not whole application must be written in Qt
• To override some Qt's behavior
• To make some actions before Qt is loaded

Android & iOS – on the edge of Qt and Java/Objective-C

Deployment process – Android

• A bit complicated
• Two overrided classes – QtActivity.java and QtApplication.java

are copied to android build folder

• Located in $QT/android_xxx/src/android/java/src/org/qtproject/qt5
• Used in AndroidManifest.xml

Android & iOS – on the edge of Qt and Java/Objective-C

Adding .java source files

• Define ANDROID_PACKAGE_SOURCE_DIR variable in .pro file,

so it points to folder with Android internal folders structure (src, res, assets, libs) or let QtCreator does it for you

• Put all .java files in proper folder structure connected with their packages

in src folder

• Put all other resources in proper folders – all of them will be copied into

the final .apk file

Android & iOS – on the edge of Qt and Java/Objective-C

Modifying app’s entry point – Android

• AndroidManifest.xml can be changed – any different Activity can be an entry point.
• QtActivity and QtApplication can be overridden

<Example>

https://github.com/FenixVoltres/QtAndroidSplash

Android & iOS – on the edge of Qt and Java/Objective-C

Deployment process – iOS

• Again, very simple
• Building a project creates Xcode project file in build folder
• It can be open an freely modified after QtCreator build.
• After any change in QtCreator the process must be repeated!

Android & iOS – on the edge of Qt and Java/Objective-C

Modifying app’s entry point – iOS

• Open Xcode project generated by QtCreator
• Modify what you want.

Android & iOS – on the edge of Qt and Java/Objective-C

WRAP UP

Android & iOS – on the edge of Qt and Java/Objective-C

Mixing Qt with native code

• Much easier on iOS than on Android
• Almost everything is possible

Good luck!

Android & iOS – on the edge of Qt and Java/Objective-C

THANK YOU!

Android & iOS – on the edge of Qt and Java/Objective-C

Qt& Am

Questions & Answers maybe

Android & iOS – on the edge of Qt and Java/Objective-C

Maciej Węglarczyk Maciej.Weglarczyk@gmail.com