Multi-OS Engine Technology Preview from Intel: First-hand Experience in creating an iOS* App Using Java*

While writing in Java, Auriga reports that it is very convenient that the syntax for the iOS API is hardly different from the original ObjC. For example, the menu based on UITableViewController has been added in the following way:

@com.intel.inde.moe.natj.general.ann.Runtime(ObjCRuntime.class)
@ObjCClassName("PatientsTableVC")
@RegisterOnStartup
public class PatientsTableVC extends UITableViewController {

    static {
        NatJ.register();
    }

    @Generated("NatJ")
    @Owned
    @Selector("alloc")
    public static native PatientsTableVC alloc();

    @Generated("NatJ")
    @Owned
    @Selector("init")
    public native PatientsTableVC init();

    @Generated("NatJ")
    protected PatientsTableVC(Pointer peer) {
        super(peer);
    }

    private ArrayList<PatientInfo> mPatients = new ArrayList<PatientInfo>();

    @Selector("prefersStatusBarHidden")
    @Override
    public boolean prefersStatusBarHidden() {
        return true;
    }

    @Selector("viewDidLoad")
    @Override
    public void viewDidLoad() {
        setTitle("Select patient:");
    }

    @Selector("numberOfSectionsInTableView:")
    @Override
    @NInt
    public long numberOfSectionsInTableView(UITableView tableView) {
        return 1;
    }

    @Selector("tableView:numberOfRowsInSection:")
    @Override
    @NInt
    public long tableViewNumberOfRowsInSection(UITableView tableView, long section) {
        return mPatients.size();
    }

    @Selector("tableView:cellForRowAtIndexPath:")
    @Override
    public UITableViewCell tableViewCellForRowAtIndexPath(UITableView tableView, NSIndexPath indexPath) {

        String reusableId = "patientCell";
        UITableViewCell cell =
            (UITableViewCell) tableView.dequeueReusableCellWithIdentifierForIndexPath(reusableId, indexPath);
        PatientInfo patient = mPatients.get((int) indexPath.row());
        cell.textLabel().setText(patient.description());

        return cell;
    }

    @Selector("prepareForSegue:sender:")
    @Generated
    public void prepareForSegueSender(UIStoryboardSegue segue, NSObject sender) {
        NSIndexPath indexPath = tableView().indexPathForSelectedRow();
        PatientInfo patient = mPatients.get((int) indexPath.row());
        MainMonitorVC controller = (MainMonitorVC) segue.destinationViewController();
        controller.setPatient(patient);
    }
}

Multi-OS Engine Technology Preview Plugin for Android Studio

Auriga engineers reported that a great advantage MOE technology preview is the depth of its plugin integration into Android Studio. The tools they needed for development were basically, provided in Android Studio. They also found that it was easy to set up the project for both iOS and Android. Auriga engineers found that all they needed to do was set up the configuration for Android and iOS versions, launch, and switch between them by choosing the one you need now. The Android Studio functionality needed to switch is depicted directly below:

Adding Waveforms

To implement the display of “running” waveforms Auriga engineers used the C code created when working with OpenGL To use that code they wrote the UIWaveFormVC controller in ObjC with C-code added. This controller renders in OpenGL View relevant points based on input data with pre-set speed and color. A code sample to this effect is directly below:

UIWaveFormVC.h
@interface UIWaveFormVC : GLKViewController
@property (nonatomic, strong) DPSampleQueue * inputQueue;

- (void)setDataQueue:(DPSampleQueue *) dataQueue;
- (void)setWaveColor:(UIColor *)waveColor;
- (void)setSampleFreq:(float)sampleFreq;

UIWaveFormVC.m
#import "UIWaveFormVC.h"
@interface UIWaveFormVC ()
@property (strong, nonatomic) EAGLContext * context;
@end
- (void)setDataQueue:(DPSampleQueue *) dataQueue {
    self.inputQueue = dataQueue;
}
- (void)viewDidLoad {
    [super viewDidLoad];
self.context =

After that, all the work is done using Java code. To transfer data to UIWaveFormVC they call the method prepareForSequeSender(), which enables reception of the instance of the controller’s class before its display and transfer of data. The source code for this is directly below:

@com.intel.inde.moe.natj.general.ann.Runtime(ObjCRuntime.class)
@ObjCClassName("MainMonitorVC")
@RegisterOnStartup
public class MainMonitorVC extends UIViewController {
    static {
        NatJ.register();
    }

    @Selector("alloc")
    public static native MainMonitorVC alloc();

    @Selector("init")
    public native MainMonitorVC init();

    @Generated("NatJ")
    protected MainMonitorVC(Pointer peer) {
        super(peer);
    }
    private QueueDispatcher mQueueDispatcher = null;

    @Selector("prepareForSegue:sender:")
    @Generated
    public void prepareForSegueSender(UIStoryboardSegue segue, NSObject sender) {
        if (segue.identifier() == null) return;

        UIWaveFormVC controller = (UIWaveFormVC) (segue.destinationViewController());
        controller.setDataQueue(sharedQueueDispatcher().queueWithID(segue.identifier()));
        controller.setSampleFreq(SAMPLE_FREQ);
        controller.setWaveColor(WAVE_GREEN);
   }

    private QueueDispatcher sharedQueueDispatcher() {
        if (mQueueDispatcher == null) {
            mQueueDispatcher = QueueDispatcher.sharedQueueDispatcher();
	  mQueueDispatcher.startDataLoading();
        }
        return mQueueDispatcher;
    }

}

Multi-OS Engine Technology Preview: Problems and Downsides

• Because of the lack of ODBC driver’s support for the database it is problematic to create one unified database for both Android and iOS versions.
• To make https work you need put in some extra effort. You have to manually add certificates of Android’s build.
• Sometimes, when using third party libraries developers will need to make changes to ProGuard configuration. But there is no option to do this for the plugin in MOE technology preview using the standard approach via Gradle. In the end Auriga engineers had to add required flags manually.

Developers can do this in proguard.cfg that is located in /Applications/Intel/INDE/multi_os_engine/tools. Take care to add the flags at the end of the document. In their case, Auriga added the following flags in order to use Retrofit:

-keepattributes *Annotation*

-keep class retrofit.** { *; }

-keepclasseswithmembers class * {

@retrofit.http.* <methods>; }

-keepattributes Signature

• There is no option to edit the storyboard in Android Studio, we had to design an interface in xCode.

On balance, however, Auriga software engineers are happy to continue using the Multi-OS Engine technology preview for mobile projects. It offers a great opportunity to gain unique experience and expertise and to prove our competence in tackling complex R&D tasks.