seems like you need to extend JTextPane to avoid wrapping
https://forums.oracle.com/thread/1210688
class JTextWrapPane extends JTextPane {
boolean wrapState = true;
JTextArea j = new JTextArea();
JTextWrapPane() {
super();
}
public JTextWrapPane(StyledDocument p_oSdLog) {
super(p_oSdLog);
}
public boolean getScrollableTracksViewportWidth() {
return wrapState;
}
public void setLineWrap(boolean wrap) {
wrapState = wrap;
}
public boolean getLineWrap(boolean wrap) {
return wrapState;
}
}
EDIT:
// instead of private JTextPane jtp = new JTextPane( sdLog );
private JTextWrapPane jtp = new JTextWrapPane( sdLog );
//and set LineWrap = (false):
jtp.setLineWrap(false);