I was going through reference document of Input Filter from the link http://developer.android.com/reference/android/text/InputFilter.html There is a mention that if source is an instance of Spanned or Spannable, the span objects in the source should be copied into the filtered result (i.e. the non-null return value). Can someone explain me the usefulness and meaning of this line.I have implemented Input Filter in my code and the source is neither spanned nor spannable.
Short answer -- if your source isn't spannable then you don't need to worry about this.
Long answer -- if your source is spannable, that means that besides text it has spans, i.e. certain areas of it marked with some attribute. An example is a string of which the first word is in bold. In this case if you don't take care of the spans as well as the text, you'll lose all special attributes.