JTextArea: get last line of text

[Aaron Boxer]

Hello,

I have subclassed a JTextArea, and am handling the keyboard events.
I would like to get the last line of text each time the user
presses carriage return. I am going to use the widget as a
serial communication terminal: send each line of text over the serial
port after CR.

Any help would be greatly appreciated.

Aaron Boxer

 

[=?ISO-8859-1?Q?Daniel_Sj=F6blom?=]

Hello,

I have subclassed a JTextArea, and am handling the keyboard events.
I would like to get the last line of text each time the user
presses carriage return. I am going to use the widget as a
serial communication terminal: send each line of text over the serial
port after CR.

Look up getLineOfOffset and getLineEnd/StartOffset in the documentation.

 

[Bill Tschumy]

Hello,

I have subclassed a JTextArea, and am handling the keyboard events.
I would like to get the last line of text each time the user
presses carriage return. I am going to use the widget as a
serial communication terminal: send each line of text over the serial
port after CR.

Any help would be greatly appreciated.

Aaron Boxer

I haven't compiled this, but this should be pretty close to what you want.

Document document = textArea.getDocument();
Element rootElem = document.getDefaultRootElement();
int numLines = rootElem.getElementCount();
Element lineElem = rootElem.getElement(numLines - 1);
int lineStart = lineElem.getStartOffset();
int lineEnd = lineElem.getEndOffset();
String lineText = document.getText(lineStart, lineEnd - lineStart);

 

[Aaron Boxer]

Hi Bill,

thanks for your reply!

I just had to change one line, because of zero offsets:

Element lineElem = rootElem.getElement(numLines - 2);


Cheers,

Aaron