package net.sourceforge.squirrel_sql.client.session.mainpanel.objecttree.tabs;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Rectangle;
import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;
//JH: sources freely available without restriction from
//http://www.discoverteenergy.com/files/LineNumber.java
public class LineNumber extends JComponent
{
private final static Color DEFAULT_BACKGROUND = new Color(204, 204, 255);
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;
// Variables for this LineNumber component
private FontMetrics fontMetrics;
private int lineHeight;
private int currentDigits;
// Metrics of the component used in the constructor
private JComponent component;
private int componentFontHeight;
private int componentFontAscent;
/**
* Convenience constructor for Text Components
*/
public LineNumber(JComponent component)
{
if (component == null)
{
setFont( DEFAULT_FONT );
this.component = this;
}
else
{
setFont( component.getFont() );
this.component = component;
}
setBackground( DEFAULT_BACKGROUND );
setForeground( DEFAULT_FOREGROUND );
setPreferredWidth( 99 );
}
/**
* Calculate the width needed to display the maximum line number
*/
public void setPreferredWidth(int lines)
{
int digits = String.valueOf(lines).length();
// Update sizes when number of digits in the line number changes
if (digits != currentDigits && digits > 1)
{
currentDigits = digits;
int width = fontMetrics.charWidth( '0' ) * digits;
Dimension d = getPreferredSize();
d.setSize(2 * MARGIN + width, HEIGHT);
setPreferredSize( d );
setSize( d );
}
}
/**
* Reset variables that are dependent on the font.
*/
public void setFont(Font font)
{
super.setFont(font);
fontMetrics = getFontMetrics( getFont() );
componentFontHeight = fontMetrics.getHeight();
componentFontAscent = fontMetrics.getAscent();
}
/**
* The line height defaults to the line height of the font for this
* component.
*/
public int getLineHeight()
{
if (lineHeight == 0)
return componentFontHeight;
else
return lineHeight;
}
/**
* Override the default line height with a positive value.
* For example, when you want line numbers for a JTable you could
* use the JTable row height.
*/
public void setLineHeight(int lineHeight)
{
if (lineHeight > 0)
this.lineHeight = lineHeight;
}
public int getStartOffset()
{
return component.getInsets().top + componentFontAscent;
}
public void paintComponent(Graphics g)
{
int lineHeight = getLineHeight();
int startOffset = getStartOffset();
Rectangle drawHere = g.getClipBounds();
// 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 + startOffset;
for (int i = startLineNumber; i <= endLineNumber; i++)
{
String lineNumber = String.valueOf(i);
int stringWidth = fontMetrics.stringWidth( lineNumber );
int rowWidth = getSize().width;
g.drawString(lineNumber, rowWidth - stringWidth - MARGIN, start);
start += lineHeight;
}
int rows = component.getSize().height / componentFontHeight;
setPreferredWidth( rows );
}
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());
JTextPane textPane = new JTextPane();
textPane.setFont( new Font("monospaced", Font.PLAIN, 12) );
textPane.setText("abc");
JScrollPane scrollPane = new JScrollPane(textPane);
panel.add(scrollPane);
scrollPane.setPreferredSize(new Dimension(300, 250));
LineNumber lineNumber = new LineNumber( textPane );
scrollPane.setRowHeaderView( lineNumber );
frame.pack();
frame.setVisible(true);
}
}