001/* LayoutManager2.java -- enhanced layout manager
002   Copyright (C) 1999, 2002 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package 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 */
051public 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