10 Common mistakes that Android Developers do

The second day keynote from DroidCon Zagreb 2016. http://droidcon.hr/en/sessions/10-common-mistakes-android-developers-do

Transcript

1. 10 Common mistakes that Android developers do Erik Hellman @ErikHellman - www.hellso!.se
2. Erik Hellman Freelance So!ware Developer Stockholm, Sweden Previously Ericsson, Sony Mobile, Spotify (and more) Drinks most coffee Author of Android Programming - Pushing the Limits
3. <shamelessPlug> </shamelessPlug>
4. 1. People are different
5. Accessability (a11y)
6. Accessibility in Action Kelly Shuster, DroidCon Berlin 2015
7. Different form factors
8. Stop doing this! <activity android:name=".ActivitySplash" android:screenOrientation="portrait"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity>
9. 2. Cross-platform assumptions
10. Cross-platform tools
11. Your first options
12. HTML5 Service Worker if ('serviceWorker' in navigator) { navigator.serviceWorker.register('/sw.js') .then(function(registration) { // Registration was successful console.log('ServiceWorker registration successful!'); }) .catch(function(err) { // registration failed :( console.log('ServiceWorker registration failed: ', err); }); }
13. Modern C++ // auto std::vector<int> container = // fetch container... for (auto it = container.begin(); it != it.end(); it++) { // type of it is std::vector<int>::iterator } // lambdas auto is_odd = [](int n) {return n%2==1;}; // Strongly typed enums enum class Options {None, One, All}; Options o = Options::All;
14. 3. Very long builds
15. ./gradle clean assembleDebug --profile
17. Don't forget the lead times of your PRs!
18. 4. Testing strategy
20. Too much or not at all?
21. Automate all the things!
22. 5. Leaking contexts
23. Looks familar? E/AndroidRuntime(379): FATAL EXCEPTION: main E/AndroidRuntime(379): java.lang.IllegalStateException: Activity has been destroyed E/AndroidRuntime(379): at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1365) E/AndroidRuntime(379): at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595) E/AndroidRuntime(379): at android.support.v4.app.BackStackRecord.commitAllowingStateLoss(BackStackRecord.java:578) E/AndroidRuntime(379): at com.app.main.AppMainTabActivity.pushFragments(AppMainTabActivity.java:650) E/AndroidRuntime(379): at com.app.home.Home$ExpandableListAdapter$1.onClick(Home.java:530) E/AndroidRuntime(379): at android.view.View.performClick(View.java:2408) E/AndroidRuntime(379): at android.view.View$PerformClick.run(View.java:8816) E/AndroidRuntime(379): at android.os.Handler.handleCallback(Handler.java:587) E/AndroidRuntime(379): at android.os.Handler.dispatchMessage(Handler.java:92) E/AndroidRuntime(379): at android.os.Looper.loop(Looper.java:123) E/AndroidRuntime(379): at android.app.ActivityThread.main(ActivityThread.java:4627) E/AndroidRuntime(379): at java.lang.reflect.Method.invokeNative(Native Method) E/AndroidRuntime(379): at java.lang.reflect.Method.invoke(Method.java:521) E/AndroidRuntime(379): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) E/AndroidRuntime(379): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) E/AndroidRuntime(379): at dalvik.system.NativeStart.main(Native Method)
24. – What do we want? – Now! – When do we want it? – Fewer race conditions! — Developers
25. Leak Canary https://github.com/square/leakcanary
26. @WorkerThread public void doNetworkStuff() { // Do network stuff here... } @MainThread public void doUiStuff() { // Update the UI here }
27. 6. Security mistakes
29. signingConfigs { release { storeFile file("./cert/release_keystore.jks") storePassword S3cr3tP4ssw0rd keyAlias android keyPassword S3cr3tP4ssw0rd } debug { storeFile file("./cert/debug_keystore.jks") storePassword "appdebug" keyAlias "debug" keyPassword "appdebug" } }
30. 7. Picking the right library!
31. Emerging and Disruptive
32. 8. API Level
33. Official stats (April 2016)
34. Android versions 2015
35. Exepctations vs Reality
36. · Track actual usage · Perform user studies in public · Play Store keeps old versions available
37. 9. Get an iPhone!
38. 10. Sharing is caring
40. Thank you for listening! @ErikHellman - www.hellsoft.se