CODEWITHSUNDEEP
swingjtextareajtextpanenimbus
Er Kaushik Chakraborty
Er Kaushik Chakraborty

Reputation: 33

How to center align text in JTextArea?


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 https://bugs.java.com/bugdatabase/view_bug;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

Upvotes: 2

Views: 18237

Answers (3)

user6315137
user6315137

Reputation:

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

Upvotes: 0

Er Kaushik Chakraborty
Er Kaushik Chakraborty

Reputation: 33

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());
    }
}

Upvotes: 1

camickr
camickr

Reputation: 324098

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());

Upvotes: 2

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