1 /*

     2  * Copyright (c) 1996, 2014, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package java.awt;

    26 

    27 /**

    28  * Defines an interface for classes that know how to layout Containers

    29  * based on a layout constraints object.

    30  *

    31  * This interface extends the LayoutManager interface to deal with layouts

    32  * explicitly in terms of constraint objects that specify how and where

    33  * components should be added to the layout.

    34  * <p>

    35  * This minimal extension to LayoutManager is intended for tool

    36  * providers who wish to the creation of constraint-based layouts.

    37  * It does not yet provide full, general support for custom

    38  * constraint-based layout managers.

    39  *

    40  * @see LayoutManager

    41  * @see Container

    42  *

    43  * @author      Jonni Kanerva

    44  */

    45 public interface LayoutManager2 extends LayoutManager {

    46 

    47     /**

    48      * Adds the specified component to the layout, using the specified

    49      * constraint object.

    50      * @param comp the component to be added

    51      * @param constraints  where/how the component is added to the layout.

    52      */

    53     void addLayoutComponent(Component comp, Object constraints);

    54 

    55     /**

    56      * Calculates the maximum size dimensions for the specified container,

    57      * given the components it contains.

    58      *

    59      * @see java.awt.Component#getMaximumSize

    60      * @see LayoutManager

    61      * @param  target the target container

    62      * @return the maximum size of the container

    63      */

    64     public Dimension maximumLayoutSize(Container target);

    65 

    66     /**

    67      * Returns the alignment along the x axis.  This specifies how

    68      * the component would like to be aligned relative to other

    69      * components.  The value should be a number between 0 and 1

    70      * where 0 represents alignment along the origin, 1 is aligned

    71      * the furthest away from the origin, 0.5 is centered, etc.

    72      *

    73      * @param  target the target container

    74      * @return the x-axis alignment preference

    75      */

    76     public float getLayoutAlignmentX(Container target);

    77 

    78     /**

    79      * Returns the alignment along the y axis.  This specifies how

    80      * the component would like to be aligned relative to other

    81      * components.  The value should be a number between 0 and 1

    82      * where 0 represents alignment along the origin, 1 is aligned

    83      * the furthest away from the origin, 0.5 is centered, etc.

    84      *

    85      * @param  target the target container

    86      * @return the y-axis alignment preference

    87      */

    88     public float getLayoutAlignmentY(Container target);

    89 

    90     /**

    91      * Invalidates the layout, indicating that if the layout manager

    92      * has cached information it should be discarded.

    93      * @param  target the target container

    94      */

    95     public void invalidateLayout(Container target);

    96 

    97 }