iOS Developers need a wide variety of skills and knowledge to perform their jobs well. These skills and knowledge have wide applications beyond iOS, especially when sticking within the realms of Mobile Application Development. This deck of slides shows some common cases where an iOS Developer can with minimal effort use their existing skills to build Android apps. Presented at iOSDevUK 2015.

1. Android Development for iOS
Developers
Darryl Bayliss
@Dazindustries

4. Showing Content (iOS)
- Storyboards
- XIBs
- Code

7. override func viewDidLoad() {
super.viewDidLoad()
let textLabel = UILabel(frame: CGRectMake(40, 40, 200, 100))
textLabel.text = "Super amazing textlabel"
self.view.addSubview(textLabel)
let button = UIButton(frame: CGRectMake(50, 150, 50, 50))
button.titleLabel?.text = "Super amazing button"
self.view.addSubview(textLabel)
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
}

8. Showing Content (Android)
- Navigation Editor Tool
- Layouts
- Code

12. @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout linearLayout = new LinearLayout(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
TextView textView = new TextView(this);
textView.setText("Super amazing TextView");
linearLayout.addView(textView);
Button button = new Button(this);
button.setText("Super amazing Button");
linearLayout.addView(button);
setContentView(linearLayout, layoutParams);
}
@Override
protected void onStart() {
super.onStart();
}
@Override
protected void onPause() {
super.onPause();
}

13. override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
protected void onStart() {
super.onStart();
}
@Override
protected void onPause() {
super.onPause();
}
View Controller Lifecycles

14. TableViews (iOS)
- Implement the Data Source / Table View
Delegates
- Override the required methods
- Perform your logic

15. class tableViewController : UIViewController, UITableViewDataSource, UITableViewDelegate {
@IBOutlet var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
tableView.delegate = self
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 10
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = UITableViewCell(style: UITableViewCellStyle.Value2, reuseIdentifier: nil)
cell.textLabel?.text = "Super amazing cell text"
return cell
}
}

16. RecyclerViews (Android)
- Create a RecyclerView
- Set RecyclerView Layout Manager
- Set RecyclerView Adapter

17. @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setAdapter(new RecyclerAdapter());
}

18. public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView textView;
public ViewHolder(TextView textView) {
super(textView);
textView = textView;
}
}
@Override
public RecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
TextView v = (TextView) LayoutInflater.from(parent.getContext())
.inflate(R.layout.recycler_item_textview, parent, false);
RecyclerAdapter.ViewHolder vh = new RecyclerAdapter.ViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(ViewHolder viewHolder, int i) {
viewHolder.textView.setText("Super amazing textview");
}
@Override
public int getItemCount() {
return 10;
}

19. User Permissions (iOS)
- Attempt to access a feature at runtime
- Handle the result

20. class DetailViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func showCamera(sender: UIButton) {
AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: { granted in
if(granted) {
// Do camera stuff here
}
else {
// Handle user rejection
}
})
}
}

21. User Permissions (Android 6.0)
- Attempt to access a feature at runtime
- Handle the result

22. public class MainActivity extends Activity {
final int CAMERA_REQUEST_CODE = 0;
Button showCameraButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
showCameraButton = (Button) findViewById(R.id.show_camera_button);
showCameraButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showCamera();
}
});
}
public void showCamera() {
if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.CAMERA}, CAMERA_REQUEST_CODE);
} else {
// ... Show camera
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == CAMERA_REQUEST_CODE && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// ... Show Camera
}
}
}

23. - Android is a mess of disparate OEMs and legacy versions
- Fragmentation is a headache for developers
- Fragmentation presents a lot of problems for enterprise…
there aren’t many good solutions
The Internet Said…
Quotes from The Next Web, Open Signal & Tech Target

24. OS Fragmentation
AndroidiOS
Stats from Apple Developer, Android Developer

26. Device Screen Sizes
AndroidiOS

27. Screen Sizes (iOS)
- Autolayout
- Setup constraints on views to
accommodate multiple screen sizes
- Use Size Classes for fine grained
constraint control

28. Screen Sizes (Android)
- Views & layouts can be designed to be
pixel independent
- Android resizes layouts based on device
screen
- Can design multiple variants of the same
layout for specific device dimensions

31. OS Fragmentation (iOS)
- Encourage users to update for new
features
- Encourage developers to support new
features unavailable on older iOS versions
- Runtime detection of OS version in code
using Availability attributes

32. OS Fragmentation (Android)
- Android Support Libraries
- Provides features that are backwards
compatible to devices running old versions
of Android
- Ability to support devices running Android
1.6 (Donut)

33. Material Design
- Androids iOS 7 moment
- A visual language based on paper / ink

34. Material Design

35. Build Targets / Gradle
Localization
Unit Testing
UI Testing
Extensions / Intents
App Content Searching

37. Quiz Question #1
• Layout?
• Activity?
• Controller?
What is the Android equivalent of a UIViewController?

38. Quiz Question #2
• Themes?
• Styles?
• Layouts?
In Android, what are the files that hold your user interface
elements for each screen called?

39. Quiz Question #3
• onCreate()?
• onAppear()?
• onStart()?
What is Androids equivalent of a viewDidLoad lifecycle call?