ojluni/src/main/java/java/awt/LayoutManager2.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
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 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package java.awt;

/**
 * Defines an interface for classes that know how to layout Containers
 * based on a layout constraints object.
 *
 * This interface extends the LayoutManager interface to deal with layouts
 * explicitly in terms of constraint objects that specify how and where
 * components should be added to the layout.
 * <p>
 * This minimal extension to LayoutManager is intended for tool
 * providers who wish to the creation of constraint-based layouts.
 * It does not yet provide full, general support for custom
 * constraint-based layout managers.
 *
 * @see LayoutManager
 * @see Container
 *
 * @author      Jonni Kanerva
 */
public interface LayoutManager2 extends LayoutManager {

    /**
     * Adds the specified component to the layout, using the specified
     * constraint object.
     * @param comp the component to be added
     * @param constraints  where/how the component is added to the layout.
     */
    void addLayoutComponent(Component comp, Object constraints);

    /**
     * Calculates the maximum size dimensions for the specified container,
     * given the components it contains.
     * @see java.awt.Component#getMaximumSize
     * @see LayoutManager
     */
    public Dimension maximumLayoutSize(Container target);

    /**
     * Returns the alignment along the x axis.  This specifies how
     * the component would like to be aligned relative to other
     * components.  The value should be a number between 0 and 1
     * where 0 represents alignment along the origin, 1 is aligned
     * the furthest away from the origin, 0.5 is centered, etc.
     */
    public float getLayoutAlignmentX(Container target);

    /**
     * Returns the alignment along the y axis.  This specifies how
     * the component would like to be aligned relative to other
     * components.  The value should be a number between 0 and 1
     * where 0 represents alignment along the origin, 1 is aligned
     * the furthest away from the origin, 0.5 is centered, etc.
     */
    public float getLayoutAlignmentY(Container target);

    /**
     * Invalidates the layout, indicating that if the layout manager
     * has cached information it should be discarded.
     */
    public void invalidateLayout(Container target);

}