Android - Do something *after* text is changed in EditText

Implement onFocusChange of setOnFocusChangeListener and there's a boolean parameter for hasFocus. When this is false, you've lost focus to another control and you should save the data of editext. for example

 EditText editText= (EditText) findViewById(R.id.editText);

 editText.setOnFocusChangeListener(new OnFocusChangeListener() {          

        public void onFocusChange(View v, boolean hasFocus) {
            if(!hasFocus) {
                //SAVE THE DATA 
            }  

        }
    });

Implement setOnFocusChangeListener for all EditTexts and you should handle Back Press event too. If the user change the data of edittext and didn't goto another EditText and pressed back then edited vallue will not save. So should use onKeyDown or onBackPressed too

As Kotlin is now official android language:

var editText = findViewById<EditText>(R.id.editText) 

editText.onFocusChangeListener = OnFocusChangeListener { _, hasFocus ->
        if (!hasFocus) { 
           //SAVE THE DATA       
        }
}