Android Custom font Spannable Typeface Span
You are going to want to write a custom TypefaceSpan. The good news is that they aren't difficult. See here for an example.
You can do the following:
SpannableString spannableString = new SpannableString("your text");Typeface typeface = Typeface.create(ResourcesCompat.getFont(this, R.font.your_font);spannableString.setSpan( new TypefaceSpan(typeface, Typeface.NORMAL)), 0, 4, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);This constructor will replace the previous style of the text, achieving what you want. However, the catch is that it was introduced in API 28.