GridBagConstraints

/*
GBC - A convenience class to tame the GridBagLayout

Copyright (C) 2002 Cay S. Horstmann (http://horstmann.com)

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/


import java.awt.*;

/**
   This class simplifies the use of the GridBagConstraints
   class.
*/
public class GBC extends GridBagConstraints 
{
   /**
      Constructs a GBC with a given gridx and gridy position and
      all other grid bag constraint values set to the default.
      @param gridx the gridx position
      @param gridy the gridy position
   */
   public GBC(int gridx, int gridy)
   {
      this.gridx = gridx;
      this.gridy = gridy;
   }

   /**
      Sets the cell spans.
      @param gridwidth the cell span in x-direction
      @param gridheight the cell span in y-direction
      @return this object for further modification
   */
   public GBC setSpan(int gridwidth, int gridheight) 
   { 
      this.gridwidth = gridwidth; 
      this.gridheight = gridheight; 
      return this;
   }

   /**
      Sets the anchor.
      @param anchor the anchor value
      @return this object for further modification
   */
   public GBC setAnchor(int anchor) 
   { 
      this.anchor = anchor; 
      return this;
   }
   
   /**
      Sets the fill direction.
      @param fill the fill direction
      @return this object for further modification
   */
   public GBC setFill(int fill) 
   { 
      this.fill = fill; 
      return this;
   }

   /**
      Sets the cell weights.
      @param weightx the cell weight in x-direction
      @param weighty the cell weight in y-direction
      @return this object for further modification
   */
   public GBC setWeight(double weightx, double weighty) 
   { 
      this.weightx = weightx; 
      this.weighty = weighty; 
      return this;
   }

   /**
      Sets the insets of this cell.
      @param distance the spacing to use in all directions
      @return this object for further modification
   */
   public GBC setInsets(int distance) 
   { 
      this.insets = new java.awt.Insets(
            distance, distance, distance, distance);
      return this;
   }

   /**
      Sets the insets of this cell.
      @param top the spacing to use on top
      @param left the spacing to use to the left
      @param bottom the spacing to use on the bottom
      @param right the spacing to use to the right
      @return this object for further modification
   */
   public GBC setInsets(int top, int left, int bottom, int right) 
   { 
      this.insets = new java.awt.Insets(
         top, left, bottom, right);
      return this;
   }

   /**
      Sets the internal padding
      @param ipadx the internal padding in x-direction
      @param ipady the internal padding in y-direction
      @return this object for further modification
   */
   public GBC setIpad(int ipadx, int ipady) 
   { 
      this.ipadx = ipadx; 
      this.ipady = ipady; 
      return this;
   }
}

引自java2核心技术 因为编写GridBagLayout的约束代码很麻烦，而这个类能够简化。