The Qt IF Android vehicle properties module is a submodule of Qt for Android Automotive. This submodule is an extension of the similar Qt IF Vehicle Functions Module.

It provides a C++ and QML wrapper for Android Automotive Vehicle Properties as a Qt IF plugin. The solution is based on templates used by the Qt Interface Framework Generator for code generation. The interface is defined by a QFace configuration file which covers the Android Automotive Vehicle Properties.

How it Works

The module encapsulates the Qt for Android Automotive JNI back end (Qt IF Android Extensions). This module facilitates access to Android vehicle properties. It provides a dedicated Qt Quick plugin to enable access using the QML language.

The set of available vehicle properties, which are grouped into feature components, is defined by the QFace configuration file together with YAML annotations file (YAML Annotations). These two files reflect the Android vehicle properties defined in AOSP sources (VHAL v2.0) and defines the property IDs mappings as well as zoning configuration. That is why modification of this interface needs to be reflected in the mentioned files and followed by rebuilding this module from source code.

Module Structure

The module consists of following components:

• The QML plugin: responsible for interfacing between the Qt Quick application and the Qt IF Vehicle Properties module.
• The Vehicle Properties Module: a Qt plugin that encapsulates the features defined by the interface configuration (QFace format). It also contains the JNI back end interface. This is a specialized implementation that interacts with the back end service (the one that directly accesses the Android car API).

Vehicle properties are grouped into the following components:

How to use it

The module can be used by directly interacting with C++ code, or by using the QML plugin. To use the plugin at the C++ code level, follow the steps described in Qt IF Vehicle Functions Module. The use of the QML plugin is presented in source code of the Qt for Android Automotive vehicle properties example. Integrate this module by following these steps:

1. If using qmake, add the dependencies of the Qt IF Android Vehicle Properties module to your qmake project file (*.pro):

   QT += ifandroidvehicleproperties interfaceframework

   If using CMake:

   find_package(Qt6 COMPONENTS InterfaceFramework)
   find_package(Qt6 COMPONENTS IfAndroidVehicleProperties)
   
   target_link_libraries(my_target PUBLIC
       Qt::InterfaceFramework
       Qt::IfAndroidVehicleProperties
   )

2. Add the paths to additional dependency libs for android runtime environment. For qmake use the following code:

   ANDROID_PACKAGE_SOURCE_DIR = $$PWD/android

   For CMake use the following code:

   set_property(TARGET my_target APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
                ${CMAKE_CURRENT_SOURCE_DIR}/android)

   Note: In order to set target property on Android use MANUAL_FINALIZATION as described in CMake manual finalization.

3. In the AndroidManifest.xml file add the proper permissions for accessing the VHAL properties (e.g. for HVAC it would be CONTROL_CAR_CLIMATE)

   <uses-permission android:name="android.car.permission.CONTROL_CAR_CLIMATE"/>

4. In the QML file add the import statement of this plugin

   import QtIf.Android.VehicleProperties 1.0

5. Define an instance of the desired component (e.g. HVAC)

   HVAC { id: climateControl }

6. The interaction with the vehicle properties is like any typical Qt property

   onClicked: {
       climateControl.setHvacAcOn(!climateControl.hvacAcOn)
   }
   text: climateControl.hvacAcOn ? "AC ON" : "AC OFF"

7. If the vehicle has an interface with zones, then the interaction with the properties needs to point to a certain zone (see Zoned HVAC Control).

Known issues and limitations

1. Currently to deploy an application using this module, additional actions are needed to meet the dependencies:
   1. Enable AndroidX in gradle.properties file by adding android.useAndroidX=true
   2. Add android.car.jar package to the APK

   For more information, see Deploying an Application on Android.

2. The Android build needs to be aligned with the vehicle interface definition used by this module, and a proper android.car.jar package needs to be delivered together with the APK like in the Qt for Android Automotive Vehicle Properties example.
3. The current version of this module uses the JNI back end for accessing the Android Car Service. To use the Qt Remote Objects back end, the module would need adjustments to the source code.
4. Property fuelDoorOpen is read-only on Android 10, but it can be written from Android 11 onward.
5. Static vehicle properties do not react on change in emulator. Static properties are supposed to be set once, during the production, by the manufacturer of the car, so Android Automotive does not broadcast it's changes. Those properties are:
   1. QIfCarInfo.infoModelYear (INFO_MODEL_YEAR)
   2. QIfCarInfo.infoFuelCapacity (INFO_FUEL_CAPACITY)
   3. QIfCarInfo.infoEvBatteryCapacity (INFO_EV_BATTERY_CAPACITY)
   4. QIfCarInfo.infoFuelDoorLocation (INFO_FUEL_DOOR_LOCATION)
   5. QIfCarInfo.infoEvPortLocation (INFO_EV_PORT_LOCATION)
   6. QIfCarInfo.infoDriverSeat (INFO_DRIVER_SEAT)

   Full list of Android Automotive static properties can be found here on AOSP: Vehicle Properties source code.