Theme attributes in android

Introduction

Lately i have been facing a weird issue with respect changing themes in android as far i knew, call setTheme() before any view creation preferably in the onCreate(savedInstanceState: Bundle) method of an activity. Everything should work as expected, there are some stackoverflow posts suggesting to call before super call in onCreate method, i seem to try everything but none seems to work.

There are also suggestions, incase your theme overrides only few attributes then theme.appleStyle() API, but still API remained un-fruitful.

Solution

However i stumbled on the blog post by Nick Butcher. After that only i realised that i had been referencing the styles directly in the xml, instead of accessing attributes.

That is

<TextView
  ...
  android:style="@style/CaptionText.Strong"
  />

instead of the above i should have been doing

 <TextView
   ...
   android:style="?CaptionText.Strong"
   />
 

In the latter i am trying to access the attributes from currently setTheme(...), which is actually the recommended approach as it makes adopting to new themes much easier. Which means tomorrow if you have dark theme with some minor change in CaptionText.Strong style, it would easily be reflected once you change the theme.