How to center align text in JTextArea? - swing

Question

I have requirement of Text wrapping + Text Centering + Nimbus Look and Feel + with a background color black.
I tried out with the following 2 components
1. JTextPane
-------supports: Text Wrapping + Text Centering using StyledDocument
-------issue : custom background color doesn't work Nimbus Look and Feel(be it disabled or enabled)
which is bug as show here http://bugs.sun.com/bugdatabase/view_bug.do;jsessionid=ab1938d61a7fd83ca2b54eb8df7?bug_id=6789980
my jdk version is : 1.6.0_33
Fixes tried :
UIManager.getLookAndFeelDefaults().put("TextPane.background", Color.RED);
but this also is unable to override the Nimbus default which is #d6d9df (214,217,223)
Can anyone help me with text Centering in the JTextArea?
Thanks in advance
1. JTextArea
-------supports: Text Wrapping + background coloring with Nimbus LnF (only when its enabled)
-------issue : Text Centering is an issue in here

Answer 1

To center text you should use a JTextPane not a JTextArea. Centering text is a big issue.
It is better to solve the background problem with the JTextPane.
When using the Nimbus LAF it looks like you need to provide a custom Painter to just paint the background as a solid color. Check out this answer by #mKorbel. You would need to change the property tag. Also in the FillPainter I changed:
g.setColor(color);
g.setColor(object.getBackground());

Answer 2

Thanks .... Working ,,,,
This is what I used ...
UIManager.getLookAndFeelDefaults().put("TextPane[Enabled].backgroundPainter", new FillPainter());`
public class FillPainter implements Painter<JComponent> {
#Override
public void paint(Graphics2D g, JComponent object, int width,int height) {
g.setColor(object.getBackground());
}
}

Answer 3

I use this to center text in JTextArea
public static void centerText (JTextArea ta)
{
BufferedImage fake1 = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
Graphics2D fake2 = fake1.createGraphics();
FontMetrics fm = fake2.getFontMetrics(ta.getFont());
int lines = ta.getLineCount();
ArrayList<String> list = new ArrayList<>();
try
{
for (int i = 0; i < lines; i++)
{
int start = ta.getLineStartOffset(i);
int end = ta.getLineEndOffset(i);
String line = ta.getText(start, end - start).replace("\n","");
list.add (line.trim());
}
}
catch (BadLocationException e)
{
System.out.println(e);
}
alignLines (list, fm, ta);
}
private static void alignLines (ArrayList<String> list, FontMetrics fm, JTextArea ta)
{
String leading = " ";
int longest = -1;
for (String s : list)
{
if (fm.stringWidth(s) > longest)
longest = fm.stringWidth(s);
}
for (int n=0; n<list.size(); n++)
{
String s = list.get(n);
if (fm.stringWidth(s) >= longest)
continue;
while (fm.stringWidth(s) < longest)
s = ' '+s+' ';
list.set(n, s);
}
StringBuilder sb = new StringBuilder();
for (String s : list)
{
sb.append(leading).append(s).append('\n');
}
ta.setText (sb.toString());
}
call CenterText with your filled JTextArea as argument