My app works before with translation from English to Korean.
See screenshot below.
I don't have to configure things like right fonts among other things.
Now it won't work and would only show Latin based characters.
I know for sure that the API I use returns the translation I need since the correct translation shows on my logcat.
But android textView doesn't display it properly since I updated all of my android studio components such as the emulator. It doesn't work properly on API 17, 18 and 19 but works on API 16 which is rather odd since if it could work on API 16, it should work on much newer versions of android too. I've also Cold Boot all my emulators to reset it, but still no changes. It also works on API 21 as show below. But definitely not on API 17-19 as I've tested. :(. Please. help. Thanks.
[Edit]: I Changed the title from "How to display Korean-Chinese-Japanese Characters in TextView?" to what it is now since supporting most languages is under encoding foreign language in Unicode it seems.
After debugging for a couple hours more searching. It seems that the current updated Android emulators for API 17-19 are buggy. Since I noticed that it doesn't display Korean Characters not only my my app, but also everywhere else like my web browser.
The reason why my app displays unicode characters in an older android versions like Android 4.1. However, it turns out it could display Japanese Characters when I tried to translate to another language that is another Unicode character. It could also properly display japanese and chinese unicode characters in my browser.
I already created a fresh Android emulator for API 17-19, but it really didn't solved the problem. Installing a new keyboard didn't do the trick either. I could't not add another language too like japanese since its not in the options. But japanese works on the emulator, so I didn't bother trying to find one for Korean.
In the end, it turns out its really an emulator (Operating System related) problem and not an android app compatibility or problem on my code. Android 4.2-4.3 (API 17-18) is both Jelly Bean anyway. Since, it works on Android 4.1 that is Jelly Bean too, problems must be in the android image updates I had update a few days ago. for Android 4.4, must be the same case then.