Adaptive Interface Capabilities

Since each car manufacturer has different user interface style guidelines, the number of lines of text, soft and hard buttons, and images supported will vary between different types of head units. The system will send information to your app about its capabilities for various user interface elements. You should use this information to create the user interface of your SDL app.

You can access these properties on the sdlManager.getSystemCapabilityManager() instance.

System Capability Manager Properties

Deprecated Properties

The following properties are deprecated on SDL Android 4.10 because as of RPC v6.0 they are deprecated. However, these properties will still be filled with information. When connected on RPC <6.0, the information will be exactly the same as what is returned in the RegisterAppInterfaceResponse and SetDisplayLayoutResponse. However, if connected on RPC >6.0, the information will be converted from the newer-style display information, which means that some information will not be available.

Image Specifics

Images may be formatted as PNG, JPEG, or BMP. You can find which image types and resolutions are supported using the system capability manager.

Since the head unit connection is often relatively slow (especially over Bluetooth), you should pay attention to the size of your images to ensure that they are not larger than they need to be. If an image is uploaded that is larger than the supported size, the image will be scaled down by Core.

ImageField field = sdlManager.getSystemCapabilityManager().getDefaultMainWindowCapability().getImageFields().get(index);
ImageResolution resolution = field.getImageResolution();

Example Image Sizes

Below is a table with example image sizes. Check the SystemCapabilityManager for the exact image sizes desired by the system you are connecting to. The connected system should be able to scale down larger sizes, but if the image you are sending is much larger than desired, then performance will be impacted.

Querying and Subscribing System Capabilities

Capabilities that can be updated can be queried and subscribed to using the SystemCapabilityManager.

Determining Support for System Capabilities

You should check if the head unit supports your desired capability before subscribing to or updating the capability.

boolean navigationSupported = sdlManager.getSystemCapabilityManager().isCapabilitySupported(SystemCapabilityType.NAVIGATION);

Manual Querying for System Capabilities

Most head units provide features that your app can use: making and receiving phone calls, an embedded navigation system, video and audio streaming, as well as supporting app services. To pull information about this capability, use the SystemCapabilityManager to query the head unit for the desired capability. If a capability is unavailable, the query will return null.

sdlManager.getSystemCapabilityManager().getCapability(SystemCapabilityType.APP_SERVICES, new OnSystemCapabilityListener() {
    @Override
    public void onCapabilityRetrieved(Object capability) {
        AppServicesCapabilities servicesCapabilities = (AppServicesCapabilities) capability;
    }

    @Override
    public void onError(String info) {
        // Handle Error
    }
}, false);

Subscribing to System Capabilities (RPC v5.1+)

In addition to getting the current system capabilities, it is also possible to subscribe for updates when the head unit capabilities change. Since this information must be queried from Core you must implement the OnSystemCapabilityListener.

Note

If supportsSubscriptions == false, you can still subscribe to capabilities, however, you must manually poll for new capability updates using getCapability(type, listener, forceUpdate) with forceUpdate set to true. All subscriptions will be automatically updated when that method returns a new value.

The DISPLAYS type can be subscribed on all SDL versions.

Checking if the Head Unit Supports Subscriptions

boolean supportsSubscriptions = sdlManager.getSystemCapabilityManager().supportsSubscriptions();

Subscribe to a Capability

sdlManager.getSystemCapabilityManager().addOnSystemCapabilityListener(SystemCapabilityType.APP_SERVICES, new OnSystemCapabilityListener() {
    @Override
    public void onCapabilityRetrieved(Object capability) {
        AppServicesCapabilities servicesCapabilities = (AppServicesCapabilities) capability;
    }

    @Override
    public void onError(String info) {
        // Handle Error 
    }
});