Programming

This is a long post. It covers several decisions like API version, distribution beyond play store, UI & network performance, and minimizing RAM, disk, and battery usage.

Android development requires tons of disconnected approaches for development and testing. Consider some scenarios To test runtime permission - Go to Settings -> Applications -> Application info of the app you are looking for and disable that permission. To test a fresh install - adb shell pm clear-data com.example To test your app under the battery-saver mode - turn on the battery saver mode by expanding the notification bar To stop the execution of an app - kill it via activity manager, adb shell am kill com.example To test your app under doze mode - first, make the device believe that it is unplugged via adb shell dumpsys battery unplug, then, make it think that it is discharging via adb shell dumpsys battery set status 3, and then enable doze mode via adb shell dumpsys deviceidle force-idle. And don’t forget to execute a set of unrelated complementary commands once you are done to bring the device back to its normal state. To see the over draw of the app - Go to the developer options and enable/disable it there. Over time, this became a significant mental burden that I first wrote some of these flows in a text file and then converted them to automated shell scripts. But when even that felt insufficient, I created a tool for myself called adb-enhanced. ...

It is impressive to see the amount of similarity which exists in Swift, Kotlin and Go, the three new languages for iOS, Android, and server-development respectively. Consider a simple, Hello World program. Swift Swift 1 2 3 4 5 func printHello() { // Type automatically inferred to string let name = "Ashish" // let declares a read-only variable print("Hello world from \(name)!") } Kotlin ...

Here’s the proper way to pull an application’s SQLite database from an Android device.

Occasionally, my mac applications end up in a corrupt state where they won’t open. I recently encountered this with Deluge. The first step to diagnose is to open Terminal and open them in the terminal via Sh 1 2 $ open -a deluge # This name is same as the name of the app (minus the ".app" portion). LSOpenURLsWithRole() failed for the application /usr/local/Caskroom/deluge/1.3.12/Deluge.app with error -10810. Now, the error is more diagnosable but still cryptic. Deluge.app above is a directory and we can navigate to the binary located at Deluge.app/Contents/MacOS/Deluge and execute the actual binary to see a more actionable error ...

Java has fewer quirks compared to C++, but sometimes I do come across surprises. A code like following will fail to compile since you are trying to initialize a variable with an uninitialized variable. Java 1 2 3 4 5 6 7 8 9 public class Sample { private final String mField1; private final String mField2 = mField1 + " two"; private Sample(String field1) { mField1 = field1; } } But if instead of directly referencing mField1, you reference indirectly via a getter method code will compile, and mField2 will get null value for mField1. ...

Almost everyone developing an Android app has seen something like this in their device logs. Bash 1 I/Choreographer(1200): Skipped 60 frames! The application may be doing too much work on its main thread. On most devices, the Android platform tries to render a new frame every 16 milliseconds (60 fps). The rendering requires that whatever work is happening on the UI thread should finish in that timeframe. Any unit of work (== Runnable) scheduled on the UI thread has to fit in that. When the work takes longer, then frames are skipped. One skipped frame is 16 ms of the hung screen. The UI looks janky and unresponsive and if the user interacts with the screen and the application does not respond in time ( 5 seconds) then Application Not Responding (ANR) shows up. ...

Android has a few good settings built right into the platform for debugging under a hidden “Developer Options” menu. You can turn them on via Settings -> About Phone -> Build Number (tap 7 times). The steps will be similar but might vary a bit across OEMs. In older versions of Android, this used to be an explicit option under the Settings tab. I find the following options to be useful for the development ...

%f in user-facing strings is dangerous. Depending on the architecture, programming language involved, version of that language and compiler optimization flags, results can vary slightly. And if there are multiple languages involved in the serving stack, it is almost impossible to argue with the outcome. If those variations are immaterial, then use %.1f or %.2f to get one or two digits of precision after the decimal point, respectively. Otherwise, don’t use %f at all. ...

One argument which some people might give in favor of using tabs is that it allows the viewer to decide how the code should appear to them. And hence, it separates the logic (indentation) from its appearance. The biggest flaw in that argument is that it renders the concept of line length limits meaningless. Line length limits and the associated rules of wrapping bring a good structure to the code. Someone looking at a piece of code with 3-levels of nesting and tab-length set to 8 will see a very different line length from someone using a tab-length of 2. Always expand tabs. ...