Testing with two emulators


Left: Google Pixel 2; Right: Google Pixel 3

For mobile app development it is often necessary to test with multiple devices to ensure compatibility.  Given that there are a wide variety of popular devices on the market, it is almost impossible to test them all.  While there are automated testing facilities, I need to experiment my app and see the results right in front of me in real time.  There are different device system images that can be downloaded.  Among the Android device images, there are two variables that require particular attention: (1) API Level, and (2) Screen-resolution.

API Level is about the operating system version.  In the picture above, the emulator at the left runs on Android 7 (API 24) with resolution 1080 x 1920 (so called Full HD), while the emulator at the right runs on Android 9+ (API 29) with resolution 1080 x 2160.  The API level and screen resolution are the primary factors that cause the app appear inconsistently among devices.  Inconsistency may not be always bad because in the newer version of API, the app often appears more modern.  Different screen resolutions (and thus width-to-height proportions) sometimes can have an impact on the alignment of user-interface components.

At the time of writing, I use a rather old physical Android phone that runs on Android 7.  In terms of performance, if the app can run well on my mediocre phone, it likely can run well on the newer, better phones.  Also, testing with the new user-interface design of the higher API level is critical.  On Android 10, for example, the app launcher icon is round instead of square; and there is an important new feature called Notification Bubble.


To finalize the testing of user-interface, it is good to have two emulators on screen at the same time.  By doing so, I can observe how the app appears on them side-by-side. Compare the app appearance on different emulators is not only effective but is also fun.  To test with two emulators on screen, I'd recommend 16 GB of RAM or more.  In my case, running two emulators and the development environment will occupy about 12 GB of RAM.  The remaining 4 GB is enough for streaming music, looking up information on the web, and other light consumption activities.


Comments

Post a Comment

Popular posts from this blog

Finding Median by Stream

Image
This small waterfall is one of the many intermediate operations of the stream. Photo taken in Algonquin, ON The Java's DoubleStream class provides a few methods for common statistics including min(), max(), sum(), and average().  For average(), what does it actually mean?  Here is the description in the specification: The average() method returns an OptionalDouble describing the arithmetic mean of elements of the stream, or an empty optional if the stream is empty. While the arithmetic mean method is handy, we likely want a median method for different needs as well.  The DoubleStream class doesn't provide a median() method but the sorted() method.  We can use the sorted() method to assist in finding the median value. Building the Median Function Given each of existing min(), max(), and average() will return an OptionalDouble, having a median() method to return the same type is preferable.  There are different ways to create a median method, and the goal here is ...
Read more

Factorial by Different Styles in Java

Here is a collection of methods of calculating factorial by different programming styles. class Factorial { // Iteration static long iterativeFactorial( int n) { long r = 1; for ( int i=1; i<=n; i++) r*=i; return r; } // Recursion static long recursiveFactorial( int n) { return n == 0 ? 1 : n * recursiveFactorial(n-1); } // Tail-recursion static long tailRecurFactorial( int n) { return tailRecurHelper(1L, n); } static long tailRecurHelper( long acc, int n) { return n == 0 ? acc : tailRecurHelper(acc*n, n-1); } // Lambda and Recursion static Function<Integer, Long> lambdaRecurFactorial = x -> x==0 ? 1L : x * Factorial.lambdaRecurFactorial.apply(x-1); // Stream static long streamFactorial ( int n) { return LongStream.rangeClosed(1, n) .reduce(1, (a, b) -> a*b); } /...
Read more

Reduction by Java Stream

For business analysis, it is often useful to reduce a list of numbers to a single value. "What is the sum of product A sold among all the invoices?" "What is the median price among all the houses sold in Toronto last month?" "What is the average annual inflation over the last 10 years?" This type of queries is reduction operation that can be handled by the Stream class.  Below are some examples to help memorizing how the reduce  method is used. Here are three different functions of calculating the sum of a list of integers. The first function is a typical for-loop.  The second and third produce the same result by using stream's reduce . Compare the functions for mnemonic.  List<Integer> list = Arrays.asList(2, 4, 6, 8, 10, 12, 14, 16); Function<List<Integer>, Integer> sumMethod1 = (numbers) -> { int sum = 0; for (Integer x : numbers) sum += x; return sum; }; System.out.println ( "sum = " + sumMethod1.apply(l...
Read more