Which layout can do this?

Question

I'm trying to layout some JLabels in my application as shown in this example:

I always have this JLabel at the middle and the number of the others JLabels is variable it can go from 1 to 30. I have tried Grid layout by choosing a good number of columns/rows and setting some empty JLabels in the white space but i can't get a good result, and can't find how to do it with MigLayout, did any one have a good layouting soulution or any other solution.

PS: I don't want to show the circle it's just to show that the JLabels are in a arranged in a circle.

Answer 1

You don't need a layout manager which specifically supports this. You can calculate the x, y positions yourself with some fairly simple trigonometry, then use a regular layout such as SpringLayout.

import java.awt.Point; import java.util.ArrayList; import java.util.List;  import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.SpringLayout;  public class CircleLayout {    /**    * Calculate x,y positions of n labels positioned in    * a circle around a central point. Assumes AWT coordinate    * system where origin (0,0) is top left.    * @param args    */   public static void main(String[] args) {     int n = 6;  //Number of labels     int radius = 100;     Point centre = new Point(200,200);      double angle = Math.toRadians(360/n);     List<Point> points = new ArrayList<Point>();     points.add(centre);      //Add points     for (int i=0; i<n; i++) {       double theta = i*angle;       int dx = (int)(radius * Math.sin(theta));       int dy = (int)(-radius * Math.cos(theta));       Point p = new Point(centre.x + dx, centre.y + dy);       points.add(p);     }      draw(points);   }    private static void draw(List<Point> points) {     JFrame frame = new JFrame("Labels in a circle");     frame.setSize(500, 500);     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);      JPanel panel = new JPanel();;     SpringLayout layout = new SpringLayout();      int count = 0;     for (Point point : points) {       JLabel label = new JLabel("Point " + count);       panel.add(label);       count++;       layout.putConstraint(SpringLayout.WEST, label, point.x, SpringLayout.WEST, panel);       layout.putConstraint(SpringLayout.NORTH, label, point.y, SpringLayout.NORTH, panel);     }      panel.setLayout(layout);      frame.add(panel);     frame.setVisible(true);    } }