Android Question EditText_TextChanged raising twice on some symbols

[.Sina.]

TextChanged enevt raises twice when i type some symbols like : ? , (not at the beginning of the text)
old and new are equle at the first time.
Is it normal ?
Is it good solution to return when old and new are equle?

 

[Erel]

My guess is that your keyboard automatically adds a space or something like that.