Mega Code Archive
Drawing Borders Within a BoxLayout-Managed Container
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import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.LayoutManager;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class BoxLayoutManagerContainerTest {
public static void main(String[] args) {
JFrame f = new JFrame("Vertical BoxLayout-managed container");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container pane = new BoxPanel();
f.setContentPane(pane);
pane.setLayout(new BoxLayout(pane, BoxLayout.Y_AXIS));
for (float align = 0.0f; align <= 1.0f; align += 0.25f) {
JTextField tf = new JTextField("X Alignment = " + align, 10);
tf.setAlignmentX(align);
pane.add(tf);
}
f.setSize(400, 300);
f.setVisible(true);
}
}
class BoxPanel extends JPanel {
public void paintChildren(Graphics g) {
super.paintChildren(g);
Dimension size = getSize();
LayoutManager manager = getLayout();
if ((manager != null) && (manager instanceof BoxLayout)) {
BoxLayout layout = (BoxLayout) manager;
boolean vertical = true;
if (vertical) {
int axis = (int) (layout.getLayoutAlignmentX(this) * size.width);
g.fillRect(axis - 1, 0, 3, size.height);
} else {
int axis = (int) (layout.getLayoutAlignmentY(this) * size.height);
g.fillRect(0, axis - 1, size.width, 3);
}
}
}
}
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