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Beitrag 177 von 2212 (8%)

Autor	TiSch
Datum	23.07.03, 11:14
Betreff	Re: Zeilennummer in einem TextArea

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Hallo,
vielleicht hilft Dir das:
import java.awt.*;
import javax.swing.*;

public class LineNumber extends JComponent
{
    private final static Color DEFAULT_BACKGROUND = new Color(230, 163, 4);
    private final static Color DEFAULT_FOREGROUND = Color.black;
    private final static Font DEFAULT_FONT = new Font("monospaced", Font.PLAIN, 12);
    
    // LineNumber height (abends when I use MAX_VALUE)
    private final static int HEIGHT = Integer.MAX_VALUE - 1000000;
    
    // Set right/left margin
    private final static int MARGIN = 5;
    
    // Line height of this LineNumber component
    private int lineHeight;
    
    // Line height of this LineNumber component
    private int fontLineHeight;
    
    //
    private int currentRowWidth;
    
    // Metrics of this LineNumber component
    private FontMetrics fontMetrics;
    
    /**
    * Convenience constructor for Text Components
    */
    public LineNumber(JComponent component)
    {
        if (component == null)
        {
            setBackground(DEFAULT_BACKGROUND);
            setForeground(DEFAULT_FOREGROUND);
            setFont(DEFAULT_FONT);
        } else
        {
            setBackground(DEFAULT_BACKGROUND);
            setForeground(component.getForeground());
            setFont(component.getFont());
        }
        
        setPreferredSize(9999);
    }
    
    public void setPreferredSize(int row)
    {
        int width = fontMetrics.stringWidth(String.valueOf(row));
        
        if (currentRowWidth < width)
        {
            currentRowWidth = width;
            setPreferredSize(new Dimension(2 * MARGIN + width, HEIGHT));
        }
    }
    
    public void setFont(Font font)
    {
        super.setFont(font);
        fontMetrics = getFontMetrics(getFont());
        fontLineHeight = fontMetrics.getHeight();
    }
    
    /**
    * The line height defaults to the line height of the font for this
    * component. The line height can be overridden by setting it to a
    * positive non-zero value.
    */
    public int getLineHeight()
    {
        if (lineHeight == 0)
        return fontLineHeight;
        else
        return lineHeight;
    }
    
    public void setLineHeight(int lineHeight)
    {
        if (lineHeight > 0)
        this.lineHeight = lineHeight;
    }
    
    public int getStartOffset()
    {
        return 4;
    }
    
    public void paintComponent(Graphics g)
    {
        int lineHeight = getLineHeight();
        int startOffset = getStartOffset();
        Rectangle drawHere = g.getClipBounds();
        // System.out.println( drawHere );
        
        // Paint the background
        
        g.setColor(getBackground());
        g.fillRect(drawHere.x, drawHere.y, drawHere.width, drawHere.height);
        
        // Determine the number of lines to draw in the foreground.
        
        g.setColor(getForeground());
        int startLineNumber = (drawHere.y / lineHeight) + 1;
        int endLineNumber = startLineNumber + (drawHere.height / lineHeight);
        
        int start = (drawHere.y / lineHeight) * lineHeight + lineHeight - startOffset;
        
        // System.out.println( startLineNumber + " : " + endLineNumber + " : " + start );
        
        for (int i = startLineNumber; i <= endLineNumber; i++)
        {
            String lineNumber = String.valueOf(i);
            int width = fontMetrics.stringWidth(lineNumber);
            g.drawString(lineNumber, MARGIN + currentRowWidth - width, start);
            start += lineHeight;
        }
        
        setPreferredSize(endLineNumber);
    }
    
    public static void main(String[] args)
    {
        JFrame frame = new JFrame("LineNumberDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        JPanel panel = new JPanel();
        frame.setContentPane(panel);
        panel.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
        panel.setLayout(new BorderLayout());
        
        JTextArea textPane = new JTextArea();
        
        JScrollPane scrollPane = new JScrollPane(textPane);
        panel.add(scrollPane);
        scrollPane.setPreferredSize(new Dimension(300, 250));
        
        LineNumber lineNumber = new LineNumber(textPane);
        lineNumber.setPreferredSize(99999);
        scrollPane.setRowHeaderView(lineNumber);
        
        frame.pack();
        frame.setVisible(true);
    }
}

PS: gehört aber eigentlich ins Swing-Forum ;)

Grüße,
Tim

System.out.println("Hello World");


Diskussionsverlauf:

Zeilennummer in einem TextArea     Re: Zeilennummer in einem TextArea

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