public static int insertChar(final Editor editor, final int tailOffset, final char c) {
Document document = editor.getDocument();
int textLength = document.getTextLength();
CharSequence chars = document.getCharsSequence();
if (tailOffset == textLength || chars.charAt(tailOffset) != c){
document.insertString(tailOffset, String.valueOf(c));
}
return moveCaret(editor, tailOffset, 1);
}
protected static int moveCaret(final Editor editor, final int tailOffset, final int delta) {