package bluej.utility;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.LayoutManager;




| This is a layout class for a container that has exactly one child component.
| The layout places that child in the centre of the container.
|
| @author mik
| @version 0.2
|
public class CenterLayout
implements LayoutManager{    
   public CenterLayout()
   {     
   }
    
   
@Override
   
public void layoutContainer(Container target)
   {
   synchronized (target.getTreeLock()) {
      Insets insets = target.getInsets();
      int maxwidth = target.getWidth() - (insets.left + insets.right);
      int maxheight = target.getHeight() - (insets.top + insets.bottom);

      Component m = target.getComponent(0);
      if (m.isVisible()) {
         Dimension d = m.getPreferredSize();
         d.width = Math.min(d.width, maxwidth);
         d.height = Math.min(d.height, maxheight);
         m.setSize(d);

               
         int hspace = maxwidth - d.width;
         int xpos = insets.left + (hspace / 2);

               
         int vspace = maxheight - d.height;
         int ypos = insets.top + (vspace / 2);

         m.setLocation(xpos, ypos);             
         }         
      }     
   }
    
   
@Override
   
public void addLayoutComponent(String name, Component comp)
   {     
}

   
@Override
   
public void removeLayoutComponent(Component comp)
   {     
}

   
@Override
   
public Dimension preferredLayoutSize(Container parent)
   {        
   Dimension d;
   if (parent.getComponentCount() > 0) {
      Component m = parent.getComponent(0);
      d = m.getPreferredSize();         
      }
       

   else {
           
   d = new Dimension(0,0);         
   }
Insets insets = parent.getInsets();
       
d.height += insets.top + insets.bottom;
       
d.width += insets.left + insets.right;
       
return d;     
}

   
@Override
   
public Dimension minimumLayoutSize(Container parent)
   {        
   Dimension d;
   if (parent.getComponentCount() > 0) {
      Component m = parent.getComponent(0);
      d = m.getMinimumSize();         
      }
       

   else {
           
   d = new Dimension(0,0);         
   }
Insets insets = parent.getInsets();
       
d.height += insets.top + insets.bottom;
       
d.width += insets.left + insets.right;
       
return d;     
} 
}