Creating a Custom Layout Manager

• download example.jar
• download src.zip
• repository

Code

final double A2 = 4.0;
panel2.setLayout(new FlowLayout() {
  @Override public void layoutContainer(Container target) {
    synchronized(target.getTreeLock()) {
      Insets insets = target.getInsets();
      int nmembers  = target.getComponentCount();
      if(nmembers<=0) return;
      int vgap = getVgap();
      int hgap = getHgap();
      int rowh = (target.getHeight()-(insets.top+insets.bottom+vgap*2))/nmembers;
      int x = insets.left + hgap;
      int y = insets.top  + vgap;
      for(int i=0;i < nmembers; i++) {
        Component m = target.getComponent(i);
        if(m.isVisible()) {
          Dimension d = m.getPreferredSize();
          m.setSize(d.width, d.height);
          m.setLocation(x, y);
          y += (vgap + Math.min(rowh, d.height));
          x = (int)(A2 * Math.sqrt(y));
        }
      }
    }
  }
});

References

• Creating a Custom Layout Manager(Japanese)