Adding OpenSSL Support for Android ◦ Android Services

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Qt Android Manifest File Configuration

The Android Manifest is an XML file necessary for any Android app. It contains app configuration for different settings and features that the app use, as well as details on the app itself, such as, package name, app name, version, etc. Permissions and hardware features can also be set from the manifest.

Qt for Android maintains a version of AndroidManifest.xml with default configuration that include features, permissions and other configuration used by the build system which are needed for building and running Qt apps on Android.

Qt Project to Manifest Configuration

Qt defines some meta-data that is passed from the build systems and to androiddeployqt which populates the manifest with the correct values without explicitly setting these in the manifest file. Such meta-data is assigned a value in the form "-- %%INSERT_VALUE%% --", for example:

 <manifest ...
     android:versionCode="-- %%INSERT_VERSION_CODE%% --"
     ...
 </manifest>

This would be populated with the version code that is set in, for example, CMake.

Qt Default Configuration

Qt sets the following manifest configuration by default:

SectionOptionDescription
<manifest>packageSets the package name. The default value is org.qtproject.example.app_name.

Warning: This field is deprecated and moved to build.gradle. It will be removed in an upcoming release.

android:installLocationSets the app's installation location, whether internal or external storage. The default value is auto.
android:versionCodeSets the internal version code. Populated from ANDROID_VERSION_CODE (qmake) and QT_ANDROID_VERSION_CODE (CMake). The default value is 1.
android:versionNameSets the public version name. Populated from ANDROID_VERSION_NAME (qmake) and QT_ANDROID_VERSION_NAME (CMake). The default value is 1.0.
<supports-screens>Sets the screen sizes that the app supports, default values are anyDensity, largeScreens, normalScreens, and smallScreens.
<application>android:nameThe application class name. Default value is org.qtproject.qt.android.bindings.QtApplication.
android:labelThe application name label. Default value is the Qt project's target name.
android:hardwareAcceleratedSets hardware acceleration preference. The default value is true.
android:requestLegacyExternalStorageWhether to use Android scoped storage. The default value is true.
android:allowBackupWhether to allow the application to participate in the backup and restore infrastructure. If this is set to false, no backup or restore of the application will ever be performed. The default value is true.
android:fullBackupOnlyWhether or not to use Auto Backup on devices where it is available. The default value is false.
<activity>android:nameThe activity class name. The default value is org.qtproject.qt.android.bindings.QtActivity.
android:configChangesLists configuration changes that the activity handles. Default value is orientation, uiMode, screenLayout, screenSize, smallestScreenSize, layoutDirection, locale, fontScale, keyboard, keyboardHidden, navigation, mcc, mnc, density.
android:launchModeThe method used to launch the activity. The default value is singleTop.
android:screenOrientationThe orientation of the activity's display on the device. The default value is unspecified.
<intent-filter>Specifies the types of intents that the activity can respond to. Default value is
 <action android:name="android.intent.action.MAIN"/>
 <category android:name="android.intent.category.LAUNCHER"/>
android:exportedSets whether the activity can be launched by components of other applications. The default value is true.

Qt Specific Meta-data

In addition to the default manifest configuration that Qt sets, Qt defines some meta-data that is valid for Qt apps only. Such meta-data is usually under the <activity> section in the form:

 <meta-data
     android:name="meta-data-name"
     android:value="meta-data-value" />

The following is a list of such meta-data defined by Qt:

Meta-data NameDescription
android.app.lib_name The filename of the native C++ library that is used by the activity.

Note: This attribute is mandatory and shouldn't be removed. Default value is the Qt project's target name.

android.app.extract_android_styleThe method used to extract the native Android Style information. For more information, see Style Extraction. The default value is minimal.
android.app.background_running Sets whether the app keeps running tasks in the background. Setting this to true is the equivalent of setting the environment variable QT_BLOCK_EVENT_LOOPS_WHEN_SUSPENDED to 0. The default value is false.

Warning: Setting this to true may cause unexpected crash if the application tries to draw after QGuiApplication::applicationStateChanged() signal is sent with a Qt::ApplicationSuspended state.

android.app.arguments Sets a list of arguments to pass to the app "arg1 arg2". Populated from ANDROID_APPLICATION_ARGUMENTS (qmake) and QT_ANDROID_APPLICATION_ARGUMENTS (CMake). Default value is not set.
android.app.splash_screen_drawable_portraitSets a drawable for a splash screen specific to portrait mode. For example: android:resource="@drawable/splash_portrait". Default value is not set.
android.app.splash_screen_drawable_landscapeSets a drawable for a splash screen specific to landscape mode. For example: android:resource="@drawable/splash_landscape". Default value is not set.
android.app.splash_screen_drawableSets a drawable for a splash screen at the start of the app.

Note: Orientation specific splash screens are checked first, if not set, this is used instead. For example: android:resource="@drawable/splash". Default value is not set.

android.app.splash_screen_stickySets whether the splash screen stays visible until explicitly hidden by the app. For more information, see QAndroidApplication::hideSplashScreen().
android.app.trace_locationSpecifies a location on device where the application can save tracing files. For example: /storage/emulated/0/Android/data/<app_package_name>/files/. This is needed when using Common Trace Format (CTF) tracing backend.

Note: The application needs storage permission for the location. Default: not set.

Application Specific Meta-data

Some meta-data attributes are application-wide, and should be placed under the <application> section:

Meta-data NameDescription
android.app.system_libs_prefix Specifies a custom system library path to use for library loading lookup. This is necessary when using Qt libraries installed outside an app's default native (JNI) library directory. The default value is /system/lib/.

Meta-data in Services

Some meta-data attributes can also be used in Services. The main ones are:

Qt Permissions and Features

Different Qt modules might require some Android permissions or features to function properly, for example, Camera permission in QtMultimedia. l{The androiddeployqt Tool} takes care of including such requirements into the Android manifest during the build. Qt defines the following lines into the manifest, which they get replaced by the actual values:

 <manifest ...
     <!-- %%INSERT_PERMISSIONS -->
     <!-- %%INSERT_FEATURES -->
     ...
 </manifest>

Note: If those lines are removed from the project manifest, Qt won't be able to include the correct permissions. So some functionalities might not work properly.

Style Extraction

Qt uses different methods to determine how Qt Widgets and Qt Quick Controls should be styled:

  • default or full: when using Qt Widgets or Qt Quick Controls 1.

    Note: This method uses some Android non-SDK interfaces, that are being restricted and removed by Google starting from Android 9.0 (API 28). For that reason, this is not recommended for Android 9.0 or greater.

  • minimal: when using Qt Quick Controls 2 and no Qt Widgets or Qt Quick Controls 1. This is faster than using the default or full options.
  • none: no style extraction.

Qt Manifest before 6.2 Release

Versions of Qt earlier than 6.2 used to have an additional set of meta-data defined by Qt. These attributes used to manage dependencies and some were used by the discontinued Ministro service. With Qt 6.2, they should be removed. Here is a list of these attributes:

  • android.app.qt_sources_resource_id
  • android.app.repository
  • android.app.bundled_libs_resource_id
  • android.app.bundle_local_qt_libs
  • android.app.use_local_qt_libs
  • android.app.libs_prefix
  • android.app.load_local_libs_resource_id
  • android.app.load_local_jars
  • android.app.static_init_classes
  • android.app.qt_libs_resource_id
  • android.app.ministro_not_found_msg
  • android.app.ministro_needed_msg
  • android.app.fatal_error_msg

For more information on the Android Manifest, see Android App Manifest.

Adding OpenSSL Support for Android ◦ Android Services

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