Android

In MusicSync, one of the views became complex and too slow to be inflated on the UI thread. So, I decided to do some Pooling around it to inflate it on the background thread and use it on the UI thread. This made the UI snappier, reducing multiple-second load times when opening some folders. However, soon I ended up with an edge case where re-opening the activity (and not the app) led to a semi-functional app. This edge case is hard as it gets triggered only in particular scenarios where the user destroys the activity via swipe up. At the same time, the app keeps running due to the attached foreground service that’s playing the media. And on activity re-creation, I got stale views! ...

Android has two distinct navigation guidelines as opposed to iOS. Getting them right is nuanced.

While trying to install a custom exception handler to catch uncaught exceptions (crashes), I ended up writing

Google Play Music was great. Apart from one missing feature about the inability to upload music from the phone to the Google Play Music library, I had no other complaints. Then it was forcefully shut down.

On Android catching Java exceptions is easy via UncaughtExceptionHandler. Catching NDK crashes is a bit more convoluted. Since the native stack is probably corrupted, you want the crash handler to run on a separate process. Also, since the system might be in an unstable shape, don’t send the crash report to your web server or do anything fancy. Just write the crash report to a file, and on the next restart of the app, send to your web server and delete it from the disk. I ended up using jndcrash package for this.

If you are building an app that uses the user’s contact book then their certain gotchas to avoid. Telephone country codes are prefix-free If a country has a country code “+91”, then no other country will get a country code like “+912” or “+913”. This scheme ensures that numbers are inherently unambiguous. Telephone numbers can have multiple representations Since most people don’t dial internationally, telecom systems implicitly assume a domestic call. So, someone dialing 612-555-1234 in the US is dialing “+1-612-555-1234”, while the same person in India is dialing “+91-612-555-1234”. Since international dialing would be more infrequent, telecoms require unique prefix numbers like “00” to distinguish whether someone is 612-555-1234 in their country or 0061-255-51234 in Austria. In some states, even the domestic area code is not explicitly required. So, a user might have stored “555-1234” as the phone number to which telecoms will implicitly prefix the user’s area code. And if the user wants to dial beyond their area, the telecom operator would require an additional “0” prefix to mark that it is an STD call. This localization has a massive implication regarding processing cleaning and normalizing phone numbers retrieved from the user’s contact book. Both country code and area code don’t contain “0”, and usually, that’s superfluous. So, while telecoms might be OK with calling or sending SMS to “0-612-555-1234”, they will treat a number like “91-0-612-555-1234” as incorrect. ...

Emulator: Process finished with exit code 1 You opened AVD Manager in Android Studio and tried to start an AVD, you got “Emulator: Process finished with exit code 1”. Following are the steps to debug this Find out the name of the emulator. Click the down arrow 🔽 which is to the right of play arrow ▶️, to find out the name of the AVD. Let’s say the name is “Nexus_5X_API_28_x86”. ...

Die with me is a chat app which can be used only when the phone’s battery is below 5%. Here is a fun way to use the app without draining your phone’s battery. Connect the phone via ADB or start Android emulator and fake the battery level to 4%. Bash 1 2 sudo pip3 install adb-enhanced adbe battery level 4 # Set battery level to 4% And now, you can use the app. After playing with the app, reset the battery level with, ...

Update: As of Mar 2022, I recommend everyone to use GitHub Actions I maintain a somewhat popular Android developer tool ( adb-enhanced). The tool is written in Python, supporting both Python 2 and 3. Testing the tool requires both Python runtime as well a running Android emulator. I, initially, used Travis CI for setting up continuous testing of this tool. Later, I felt that Travis CI was too slow and when I came across Circle CI, I decided to give it a try. As of now, both Travis and Circle CI are used for testing. Here is what I learned from my experience.

WebView debugging can be enabled via “WebView.setWebContentsDebuggingEnabled(true)”. Leaving WebView debugging enabled in production Android apps is a bad idea. Anyone who gets hold of the unlocked phone can access the app’s data forever.