source: trunk/gcc/libjava/java/awt/LayoutManager2.java

/* LayoutManager2.java -- enhanced layout manager
   Copyright (C) 1999, 2002 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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02111-1307 USA.

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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package java.awt;

/**
 * Layout manager for laying out containers based on contraints. The
 * constraints control how the layout will proceed.
 *
 * @author Aaron M. Renn <arenn@urbanophile.com>
 * @see LayoutManager
 * @see Container
 * @since 1.0
 * @status updated to 1.4
 */
public interface LayoutManager2 extends LayoutManager
{
  /**
   * Adds the specified component to the layout, with the specified
   * constraint object.
   *
   * @param component the component to add
   * @param constraint the constraint to satisfy
   */
  void addLayoutComponent(Component component, Object contraint);

  /**
   * Determines the maximum size of the specified target container.
   *
   * @param target the container to lay out
   * @return the maximum size of the container
   * @see Component#getMaximumSize()
   */
  Dimension maximumLayoutSize(Container target);

  /**
   * Returns the preferred X axis alignment for the specified target
   * container.  This value will range from 0 to 1 where 0 is alignment
   * closest to the origin, 0.5 is centered, and 1 is aligned furthest
   * from the origin.
   *
   * @param target the target container
   * @return the x-axis alignment preference
   */
  float getLayoutAlignmentX(Container target);

  /**
   * Returns the preferred Y axis alignment for the specified target
   * container.  This value will range from 0 to 1 where 0 is alignment
   * closest to the origin, 0.5 is centered, and 1 is aligned furthest
   * from the origin.
   *
   * @param target the target container
   * @return the y-axis alignment preference
   */
  float getLayoutAlignmentY(Container target);

  /**
   * Forces the layout manager to purge any cached information about the
   * layout of the target container.  This will force it to be recalculated.
   *
   * @param target the target container
   */
  void invalidateLayout(Container target);
} // interface LayoutManager2