Android

KDE Software on Android

Android is currently the mobile platform regarding market share and number of provided applications. Hence, it is a platform very well suited to increase the availability and usage of applications by the KDE community. In the following, we give an overview of the technical steps required to setup a build system for cross-compiling a Qt5/KF5 based Android application, the necessary steps to deploy it, and a reference list of the porting steps by different applications/people.

If you enter the field of cross-compiling and Qt on Android for the first time, the best start is to follow our tutorial:

• KDE an Android Tutorial

Build Environment

There are different ways to setup a build environment:

1. Use Ready-to-Build Docker Container - This is the most convenient way to setup a system. It also brings the advantage to have a clear separation between your Linux build system and your cross-compile system; in particularly when you require several cross-compiled libraries for your application.
2. Setup your Build Environment Manually - This tutorial for setting up the cross-compiling environment requires considerably more time and brings the disadvantage to make no clear separation between your system and the cross-compile environment.

Building

Example: Building Marble

cd /opt/android
git clone kde:marble
mkdir marble/build
cd marble/build
cmake -DCMAKE_PREFIX_PATH=${Qt5_android} -DCMAKE_TOOLCHAIN_FILE=/PATH/TO/ECM/toolchain/Android.cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../export  ..
make install/strip

Note:

• /PATH/TO/ECM/toolchain/Android.cmake must be replaced with the actual path to toolchain/Android.cmake, if using the docker image it probably is at /opt/android/kde/install/share/ECM/toolchain/Android.cmake
• make install/strip strips build symbols from the binaries and reduces sizes considerably

Building with KDESRC-BUILD

For building the below mentioned frameworks on Android, you can use the following kdesrc-buildrc config file:

cd /opt/android
git clone git://anongit.kde.org/scratch/cordlandwehr/kdesrc-conf-android.git
mkdir -p extragear/kdesrc-build
git clone git://anongit.kde.org/kdesrc-build extragear/kdesrc-build
ln -s extragear/kdesrc-build/kdesrc-build kdesrc-build
ln -s kdesrc-conf-android/kdesrc-buildrc kdesrc-buildrc
./kdesrc-build extra-cmake-modules frameworks-android

Packaging and Deployment of APKs

Note

See ECM Toolchain documentation, to be added here as example

Status of KDE Frameworks 5

The following frameworks can currently be used for Qt5/KF5 based applications. They are not (yet?) provided as precompiled libraries but can easily be compiled via kdesrc-build.

Built Successfully

• kconfig (note: unit tests must be disabled)
• kcompletion
• kitemmodels
• kitemviews
• kcodecs
• karchive
• kguiaddons
• kwidgetsaddons
• attica
• kdnssd
• kapidox
• kimageformats
• kplotting
• ki18n (libintl-lite is required, since BIONIC does not fully support gettext)

Current Blockers

The following frameworks cannot yet be built and block building of further Tier 1 frameworks:

• kcoreaddons: unix specific backend not compatible with Android's libc

Further References

References:

• KDE Android - Discussion Mailing List
• Phabricator Project
• Extra-CMake-Modules Toolchain: API documentation

Application specific build instructions:

• Marble: build instructions

Blog posts about building for Android (careful: instructions may be outdated)

• 2015-09 - Dennis Nienhüser: Announcing Marble Maps for Android Open Beta
• 2015-04 - Péterffy Gábor: Marble is coming to Android
• 2015-01 - GCompris Devels: GCompris is now released on Android
• 2014-06 - Alex Pol: KDE Software on Android