Please help me in JTextArea

Question

Hi,
Is there any way of constructing a JTextArea with the specified number of rows and columns(say 4 rows and 30 columns).
I tried with JTextArea(4,30). But in this case the visible area only is 4 rows. Is there any way to construct a JTextArea which can limit my entry to 4 rows in all occasions(irrespective of whatever may the capacity)
e.g.
The Text can contain
Line no.1
no.2
no.3
no. 4
If I press enter after this should restrict my entry

Answer 1

Well there is no real way to predict what will happen when the next character is added to the text area. Also you requirement isn't complete. For example you don't state whether you are using word or character wrapping on the text area. A couple of suggestions.
If you use a monospaced font, then the maximum number of characters that can be displayed is rows * columns or 120 in your example. The Swing tutorial on [url http://java.sun.com/docs/books/tutorial/uiswing/components/generaltext.html#filter]General Text Component Features show you how to use a DocumentFilter to limit the number of characters added to a Document,
Or maybe you can use a DocumentListerner. An event gets fired after every addition to the Document. You could then use the modelToView(...) method of the text area to determine the view positon of the last character in the Document. If the Y position is greater than 4 * the row height then you know it is painted on the 5th line and you would need to undo the last insertion.