Any algorithm for Text Edit for Limited Text Display

[sakthii]

I am emulating mobile in windows platform.. so I have two text box emulating 2 lines of LCD of mobile. Max number of character that i can store in memory can be 50 per line, but the only 20 characters can be displayed in LCD(text box) at any point of time. I have to take of scrolling left, scrolling right, including insertion and deletion of character in LCD(text box) I know i have to take of Cursor position, and possibly have MasterBuffer which will contain the 50 characters and TemporaryBuffer which shall contain 20 characters to display. I can work out a logic to take care of insertion, deletion etc. But before i start doing my own logic, i wish to know is there any algorithm defined for it already as or any library available or any kind of class.. or code snippet.. i dont want to start from ground zero if it is already something is available.. as i felt text editing in mobile is common.. Let me know if you want more info.. Advance thanks on your reply!