Name: boT120536 Date: 02/22/2001


java version "1.3.1-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1-beta-b15)
Java HotSpot(TM) Client VM (build 1.3.1beta-b15, mixed mode)

Create a JTree in the Java L&F, and set "JTree.lineStyle" to "Angled", to draw
connecting lines. Expand the bottom-most parent node, and click around on some
of its children. To the left of some of the clicked nodes, a single errant
pixel is drawn. (It's hard to see, because it's a single light-purple pixel on
a white background.)

paintVerticalLine() is getting called with top > bottom, causing this extra
pixel to appear. (It doesn't happen on the Windows L&F, because WindowsTreeUI
overrides this method, and calls a different method that does nothing if top >
bottom.)

If you run the following program, one of the output lines will be something
like:

v: 7 92 63

import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.metal.*;

public class TreeTest
{
public final static void main (String[] args)
{
try
{
JFrame f = new JFrame("hi");
f.setBounds(100,100,400,600);

JTree tree = new JTree();
tree.putClientProperty("JTree.lineStyle", "Angled");
tree.setUI(new MyTreeUI());
f.getContentPane().add(tree);

f.show();
}
catch(Exception ex)
{
ex.printStackTrace();
}
}

private static class MyTreeUI extends MetalTreeUI
{
protected void paintVerticalLine( Graphics g,
JComponent c, int x, int top, int bottom )
{
System.out.println("v: " + x + " " + top + " "
+ bottom);
super.paintVerticalLine(g, c, x, top, bottom);
}

protected void paintHorizontalLine( Graphics g,
JComponent c, int y, int left, int right )
{
System.out.println("h: " + y + " " + left + " "
+ right);
super.paintHorizontalLine(g, c, y, left, right);
}
}
}
(Review ID: 117514)
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