001    /* LayoutManager2.java -- enhanced layout manager
002       Copyright (C) 1999, 2002 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.awt;
040    
041    /**
042     * Layout manager for laying out containers based on contraints. The
043     * constraints control how the layout will proceed.
044     *
045     * @author Aaron M. Renn (arenn@urbanophile.com)
046     * @see LayoutManager
047     * @see Container
048     * @since 1.0
049     * @status updated to 1.4
050     */
051    public interface LayoutManager2 extends LayoutManager
052    {
053      /**
054       * Adds the specified component to the layout, with the specified
055       * constraints object.
056       *
057       * @param component the component to add
058       * @param constraints the constraints to satisfy
059       */
060      void addLayoutComponent(Component component, Object constraints);
061    
062      /**
063       * Determines the maximum size of the specified target container.
064       *
065       * @param target the container to lay out
066       * @return the maximum size of the container
067       * @see Component#getMaximumSize()
068       */
069      Dimension maximumLayoutSize(Container target);
070    
071      /**
072       * Returns the preferred X axis alignment for the specified target
073       * container.  This value will range from 0 to 1 where 0 is alignment
074       * closest to the origin, 0.5 is centered, and 1 is aligned furthest
075       * from the origin.
076       *
077       * @param target the target container
078       * @return the x-axis alignment preference
079       */
080      float getLayoutAlignmentX(Container target);
081    
082      /**
083       * Returns the preferred Y axis alignment for the specified target
084       * container.  This value will range from 0 to 1 where 0 is alignment
085       * closest to the origin, 0.5 is centered, and 1 is aligned furthest
086       * from the origin.
087       *
088       * @param target the target container
089       * @return the y-axis alignment preference
090       */
091      float getLayoutAlignmentY(Container target);
092    
093      /**
094       * Forces the layout manager to purge any cached information about the
095       * layout of the target container.  This will force it to be recalculated.
096       *
097       * @param target the target container
098       */
099      void invalidateLayout(Container target);
100    } // interface LayoutManager2