Basic Porting
Porting Applications to Android
CMake
Since Qt6, additional CMake code must be added to build APKs:
include(ECMAddAndroidApk)
ecm_add_android_apk(myapp ANDROID_DIR ${CMAKE_CURRENT_SOURCE_DIR}/android)
${CMAKE_CURRENT_SOURCE_DIR}/android
is the directory which contains the AndroidManifest.xml
,
splash.xml
and icon files (see following sections):
android/AndroidManifest.xml
android/res/drawable/alligator.png
android/res/drawable/splash.xml
AndroidManifest.xml
Porting an application to Android requires adding an AndroidManifest.xml
containing basic information about the app.
A basic AndroidManifest.xml
may look like this:
<?xml version='1.0' encoding='utf-8'?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="org.kde.alligator"
android:versionName="0.0.1"
android:versionCode="1588098483"
android:installLocation="auto">
<supports-screens android:largeScreens="true" android:normalScreens="true" android:anyDensity="true" android:smallScreens="true"/>
<!-- %%INSERT_PERMISSIONS -->
<!-- %%INSERT_FEATURES -->
<application android:name="org.qtproject.qt.android.bindings.QtApplication" android:label="Alligator" android:icon="@drawable/alligator">
<activity android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation"
android:name="org.qtproject.qt.android.bindings.QtActivity"
android:label="Alligator"
android:windowSoftInputMode="adjustResize"
android:launchMode="singleTop"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
<meta-data android:name="android.app.lib_name" android:value="alligator"/>
<meta-data android:name="android.app.repository" android:value="default"/>
<meta-data android:name="android.app.qt_libs_resource_id" android:resource="@array/qt_libs"/>
<meta-data android:name="android.app.bundled_libs_resource_id" android:resource="@array/bundled_libs"/>
<meta-data android:name="android.app.extract_android_style" android:value="minimal"/>
<!-- Deploy Qt libs as part of package -->
<meta-data android:name="android.app.bundle_local_qt_libs" android:value="-- %%BUNDLE_LOCAL_QT_LIBS%% --"/>
<meta-data android:name="android.app.load_local_libs_resource_id" android:resource="@array/load_local_libs"/>
<!-- Run with local libs -->
<meta-data android:name="android.app.use_local_qt_libs" android:value="-- %%USE_LOCAL_QT_LIBS%% --"/>
<meta-data android:name="android.app.libs_prefix" android:value="/data/local/tmp/qt/"/>
<meta-data android:name="android.app.load_local_libs" android:value="-- %%INSERT_LOCAL_LIBS%% --"/>
<meta-data android:name="android.app.load_local_jars" android:value="-- %%INSERT_LOCAL_JARS%% --"/>
<meta-data android:name="android.app.static_init_classes" android:value="-- %%INSERT_INIT_CLASSES%% --"/>
<!-- Messages maps -->
<meta-data android:value="@string/fatal_error_msg" android:name="android.app.fatal_error_msg"/>
<meta-data android:value="@string/unsupported_android_version" android:name="android.app.unsupported_android_version"/>
<!-- Splash screen -->
<meta-data android:name="android.app.splash_screen_drawable" android:resource="@drawable/splash"/>
<!-- Background running -->
<meta-data android:name="android.app.background_running" android:value="false"/>
<!-- auto screen scale factor -->
<meta-data android:name="android.app.auto_screen_scale_factor" android:value="true"/>
</activity>
</application>
</manifest>
Exporting the main function
Most of this file is just boilerplate code that can be pasted directly into your application. Every occurrence of the applications name (in this case alligator
or Alligator
) and the package (org.kde.alligator
) must be changed to the name and package of the application being ported. If the application requires any permissions (for example if it accesses the internet, bluetooth or location services), those must be added here.
For the app to successfully run on android, the main
function needs to be exported. To do this, add a Q_DECL_EXPORT
to the function header. Since it's only required on android, you can add an #ifdef
so that it is only added on android.
#ifdef Q_OS_ANDROID
Q_DECL_EXPORT
#endif
int main(int argc, char *argv[])
Icon
The application's icon must be included as an image file. The android:icon
parameter in AndroidManifest.xml
must be set accordingly.
Splash screen
To create a splash screen for application startup, a splash.xml
file must be created with this content:
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:width="128dp" android:height="128dp" android:gravity="center">
<bitmap
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="fitXY"
android:src="@drawable/alligator"/>
</item>
</layer-list>
The android:src
parameter must be set to the application's icon.