Hi,
The Java Tutorials [1] say this about the dash_array parameter of
BasicStroke():
The dash array defines the dash pattern. Alternating elements in the
array represent the dash length and the length of the space between
dashes in user coordinate units. Element 0 represents the first dash,
element 1 the first space, and so on.
However, in openjdk6 (and openjdk7 - I havent tested explicitly, just
looked at the code) it seems to be the other way around: element 0
represent the first space and element 1 the first dash (and so on). The
attached program, when run with openjdk6, produces a solid black border
around the button text instead of no border.
The attached patch tries to fix the problem by initializing the renderer
with dashOn = true so that the first element of the array produces a
dash. The second element then produces a space and so on.
Cheers,
Omair
[1] http://java.sun.com/docs/books/tutorial/2d/geometry/strokeandfill.html
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.RenderingHints;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
public class DashStrokeButton extends JButton {
public DashStrokeButton(String string) {
super(string);
}
@Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D graphics = (Graphics2D) g;
// BasicStroke dashStroke = new BasicStroke(1.0f, BasicStroke.CAP_ROUND,
// BasicStroke.JOIN_ROUND, 1.0f, new float[] { 0.0f, 2.0f }, 0.0f);
BasicStroke dashStroke = new BasicStroke(1.0f, BasicStroke.CAP_ROUND,
BasicStroke.JOIN_ROUND, 5.0f, new float[] { 0.0f, 10.0f },
17.0f);
graphics.setStroke(dashStroke);
graphics.setColor(Color.BLACK);
graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_OFF);
Insets insets = this.getInsets();
graphics.drawRect(insets.left - 1, insets.top - 1, this.getWidth()
- insets.left - insets.right + 2, this.getHeight() - insets.top
- insets.bottom + 2);
}
public static void drawGui() {
JFrame window = new JFrame("main window");
DashStrokeButton dsb = new DashStrokeButton("Dash Button");
window.getContentPane().add(dsb);
window.pack();
window.setVisible(true);
window.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
drawGui();
}
});
}
}
--- jdk/src/share/classes/sun/java2d/pisces/Dasher.java.orig 2009-01-13 12:14:53.000000000 -0500
+++ jdk/src/share/classes/sun/java2d/pisces/Dasher.java 2009-01-13 12:15:09.000000000 -0500
@@ -120,7 +120,7 @@
// Normalize so 0 <= phase < dash[0]
int idx = 0;
- dashOn = false;
+ dashOn = true;
int d;
while (phase >= (d = dash[idx])) {
phase -= d;
