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

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

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

 * published by the Free Software Foundation.  Oracle designates this

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

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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

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 * accompanied this code).

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 *

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package java.awt;

import java.util.Hashtable;

import java.util.Arrays;

/**

 * The <code>GridBagLayout</code> class is a flexible layout

 * manager that aligns components vertically, horizontally or along their

 * baseline without requiring that the components be of the same size.

 * Each <code>GridBagLayout</code> object maintains a dynamic,

 * rectangular grid of cells, with each component occupying

 * one or more cells, called its <em>display area</em>.

 * <p>

 * Each component managed by a <code>GridBagLayout</code> is associated with

 * an instance of {@link GridBagConstraints}.  The constraints object

 * specifies where a component's display area should be located on the grid

 * and how the component should be positioned within its display area.  In

 * addition to its constraints object, the <code>GridBagLayout</code> also

 * considers each component's minimum and preferred sizes in order to

 * determine a component's size.

 * <p>

 * The overall orientation of the grid depends on the container's

 * {@link ComponentOrientation} property.  For horizontal left-to-right

 * orientations, grid coordinate (0,0) is in the upper left corner of the

 * container with x increasing to the right and y increasing downward.  For

 * horizontal right-to-left orientations, grid coordinate (0,0) is in the upper

 * right corner of the container with x increasing to the left and y

 * increasing downward.

 * <p>

 * To use a grid bag layout effectively, you must customize one or more

 * of the <code>GridBagConstraints</code> objects that are associated

 * with its components. You customize a <code>GridBagConstraints</code>

 * object by setting one or more of its instance variables:

 *

 * <dl>

 * <dt>{@link GridBagConstraints#gridx},

 * {@link GridBagConstraints#gridy}

 * <dd>Specifies the cell containing the leading corner of the component's

 * display area, where the cell at the origin of the grid has address

 * <code>gridx&nbsp;=&nbsp;0</code>,

 * <code>gridy&nbsp;=&nbsp;0</code>.  For horizontal left-to-right layout,

 * a component's leading corner is its upper left.  For horizontal

 * right-to-left layout, a component's leading corner is its upper right.

 * Use <code>GridBagConstraints.RELATIVE</code> (the default value)

 * to specify that the component be placed immediately following

 * (along the x axis for <code>gridx</code> or the y axis for

 * <code>gridy</code>) the component that was added to the container

 * just before this component was added.

 * <dt>{@link GridBagConstraints#gridwidth},

 * {@link GridBagConstraints#gridheight}

 * <dd>Specifies the number of cells in a row (for <code>gridwidth</code>)

 * or column (for <code>gridheight</code>)

 * in the component's display area.

 * The default value is 1.

 * Use <code>GridBagConstraints.REMAINDER</code> to specify

 * that the component's display area will be from <code>gridx</code>

 * to the last cell in the row (for <code>gridwidth</code>)

 * or from <code>gridy</code> to the last cell in the column

 * (for <code>gridheight</code>).

 *

 * Use <code>GridBagConstraints.RELATIVE</code> to specify

 * that the component's display area will be from <code>gridx</code>

 * to the next to the last cell in its row (for <code>gridwidth</code>

 * or from <code>gridy</code> to the next to the last cell in its

 * column (for <code>gridheight</code>).

 *

 * <dt>{@link GridBagConstraints#fill}

 * <dd>Used when the component's display area

 * is larger than the component's requested size

 * to determine whether (and how) to resize the component.

 * Possible values are

 * <code>GridBagConstraints.NONE</code> (the default),

 * <code>GridBagConstraints.HORIZONTAL</code>

 * (make the component wide enough to fill its display area

 * horizontally, but don't change its height),

 * <code>GridBagConstraints.VERTICAL</code>

 * (make the component tall enough to fill its display area

 * vertically, but don't change its width), and

 * <code>GridBagConstraints.BOTH</code>

 * (make the component fill its display area entirely).

 * <dt>{@link GridBagConstraints#ipadx},

 * {@link GridBagConstraints#ipady}

 * <dd>Specifies the component's internal padding within the layout,

 * how much to add to the minimum size of the component.

 * The width of the component will be at least its minimum width

 * plus <code>ipadx</code> pixels. Similarly, the height of

 * the component will be at least the minimum height plus

 * <code>ipady</code> pixels.

 * <dt>{@link GridBagConstraints#insets}

 * <dd>Specifies the component's external padding, the minimum

 * amount of space between the component and the edges of its display area.

 * <dt>{@link GridBagConstraints#anchor}

 * <dd>Specifies where the component should be positioned in its display area.

 * There are three kinds of possible values: absolute, orientation-relative,

 * and baseline-relative

 * Orientation relative values are interpreted relative to the container's

 * <code>ComponentOrientation</code> property while absolute values

 * are not.  Baseline relative values are calculated relative to the

 * baseline.  Valid values are:

 *

 * <center><table BORDER=0 WIDTH=800

 *        SUMMARY="absolute, relative and baseline values as described above">

 * <tr>

 * <th><P style="text-align:left">Absolute Values</th>

 * <th><P style="text-align:left">Orientation Relative Values</th>

 * <th><P style="text-align:left">Baseline Relative Values</th>

 * </tr>

 * <tr>

 * <td>

 * <ul style="list-style-type:none">

 * <li><code>GridBagConstraints.NORTH</code></li>

 * <li><code>GridBagConstraints.SOUTH</code></li>

 * <li><code>GridBagConstraints.WEST</code></li>

 * <li><code>GridBagConstraints.EAST</code></li>

 * <li><code>GridBagConstraints.NORTHWEST</code></li>

 * <li><code>GridBagConstraints.NORTHEAST</code></li>

 * <li><code>GridBagConstraints.SOUTHWEST</code></li>

 * <li><code>GridBagConstraints.SOUTHEAST</code></li>

 * <li><code>GridBagConstraints.CENTER</code> (the default)</li>

 * </ul>

 * </td>

 * <td>

 * <ul style="list-style-type:none">

 * <li><code>GridBagConstraints.PAGE_START</code></li>

 * <li><code>GridBagConstraints.PAGE_END</code></li>

 * <li><code>GridBagConstraints.LINE_START</code></li>

 * <li><code>GridBagConstraints.LINE_END</code></li>

 * <li><code>GridBagConstraints.FIRST_LINE_START</code></li>

 * <li><code>GridBagConstraints.FIRST_LINE_END</code></li>

 * <li><code>GridBagConstraints.LAST_LINE_START</code></li>

 * <li><code>GridBagConstraints.LAST_LINE_END</code></li>

 * </ul>

 * </td>

 * <td>

 * <ul style="list-style-type:none">

 * <li><code>GridBagConstraints.BASELINE</code></li>

 * <li><code>GridBagConstraints.BASELINE_LEADING</code></li>

 * <li><code>GridBagConstraints.BASELINE_TRAILING</code></li>

 * <li><code>GridBagConstraints.ABOVE_BASELINE</code></li>

 * <li><code>GridBagConstraints.ABOVE_BASELINE_LEADING</code></li>

 * <li><code>GridBagConstraints.ABOVE_BASELINE_TRAILING</code></li>

 * <li><code>GridBagConstraints.BELOW_BASELINE</code></li>

 * <li><code>GridBagConstraints.BELOW_BASELINE_LEADING</code></li>

 * <li><code>GridBagConstraints.BELOW_BASELINE_TRAILING</code></li>

 * </ul>

 * </td>

 * </tr>

 * </table></center>

 * <dt>{@link GridBagConstraints#weightx},

 * {@link GridBagConstraints#weighty}

 * <dd>Used to determine how to distribute space, which is

 * important for specifying resizing behavior.

 * Unless you specify a weight for at least one component

 * in a row (<code>weightx</code>) and column (<code>weighty</code>),

 * all the components clump together in the center of their container.

 * This is because when the weight is zero (the default),

 * the <code>GridBagLayout</code> object puts any extra space

 * between its grid of cells and the edges of the container.

 * </dl>

 * <p>

 * Each row may have a baseline; the baseline is determined by the

 * components in that row that have a valid baseline and are aligned

 * along the baseline (the component's anchor value is one of {@code

 * BASELINE}, {@code BASELINE_LEADING} or {@code BASELINE_TRAILING}).

 * If none of the components in the row has a valid baseline, the row

 * does not have a baseline.

 * <p>

 * If a component spans rows it is aligned either to the baseline of

 * the start row (if the baseline-resize behavior is {@code

 * CONSTANT_ASCENT}) or the end row (if the baseline-resize behavior

 * is {@code CONSTANT_DESCENT}).  The row that the component is

 * aligned to is called the <em>prevailing row</em>.

 * <p>

 * The following figure shows a baseline layout and includes a

 * component that spans rows:

 * <center><table summary="Baseline Layout">

 * <tr ALIGN=CENTER>

 * <td>

 * <img src="doc-files/GridBagLayout-baseline.png"

 *  alt="The following text describes this graphic (Figure 1)." style="float:center">

 * </td>

 * </table></center>

 * This layout consists of three components:

 * <ul><li>A panel that starts in row 0 and ends in row 1.  The panel

 *   has a baseline-resize behavior of <code>CONSTANT_DESCENT</code> and has

 *   an anchor of <code>BASELINE</code>.  As the baseline-resize behavior

 *   is <code>CONSTANT_DESCENT</code> the prevailing row for the panel is

 *   row 1.

 * <li>Two buttons, each with a baseline-resize behavior of

 *   <code>CENTER_OFFSET</code> and an anchor of <code>BASELINE</code>.

 * </ul>

 * Because the second button and the panel share the same prevailing row,

 * they are both aligned along their baseline.

 * <p>

 * Components positioned using one of the baseline-relative values resize

 * differently than when positioned using an absolute or orientation-relative

 * value.  How components change is dictated by how the baseline of the

 * prevailing row changes.  The baseline is anchored to the

 * bottom of the display area if any components with the same prevailing row

 * have a baseline-resize behavior of <code>CONSTANT_DESCENT</code>,

 * otherwise the baseline is anchored to the top of the display area.

 * The following rules dictate the resize behavior:

 * <ul>

 * <li>Resizable components positioned above the baseline can only

 * grow as tall as the baseline.  For example, if the baseline is at 100

 * and anchored at the top, a resizable component positioned above the

 * baseline can never grow more than 100 units.

 * <li>Similarly, resizable components positioned below the baseline can

 * only grow as high as the difference between the display height and the

 * baseline.

 * <li>Resizable components positioned on the baseline with a

 * baseline-resize behavior of <code>OTHER</code> are only resized if

 * the baseline at the resized size fits within the display area.  If

 * the baseline is such that it does not fit within the display area

 * the component is not resized.

 * <li>Components positioned on the baseline that do not have a

 * baseline-resize behavior of <code>OTHER</code>

 * can only grow as tall as {@code display height - baseline + baseline of component}.

 * </ul>

 * If you position a component along the baseline, but the

 * component does not have a valid baseline, it will be vertically centered

 * in its space.  Similarly if you have positioned a component relative

 * to the baseline and none of the components in the row have a valid

 * baseline the component is vertically centered.

 * <p>

 * The following figures show ten components (all buttons)

 * managed by a grid bag layout.  Figure 2 shows the layout for a horizontal,

 * left-to-right container and Figure 3 shows the layout for a horizontal,

 * right-to-left container.

 *

 * <center><table WIDTH=600 summary="layout">

 * <tr ALIGN=CENTER>

 * <td>

 * <img src="doc-files/GridBagLayout-1.gif" alt="The preceding text describes this graphic (Figure 1)." style="float:center; margin: 7px 10px;">

 * </td>

 * <td>

 * <img src="doc-files/GridBagLayout-2.gif" alt="The preceding text describes this graphic (Figure 2)." style="float:center; margin: 7px 10px;">

 * </td>

 * <tr ALIGN=CENTER>

 * <td>Figure 2: Horizontal, Left-to-Right</td>

 * <td>Figure 3: Horizontal, Right-to-Left</td>

 * </tr>

 * </table></center>

 * <p>

 * Each of the ten components has the <code>fill</code> field

 * of its associated <code>GridBagConstraints</code> object

 * set to <code>GridBagConstraints.BOTH</code>.

 * In addition, the components have the following non-default constraints:

 *

 * <ul>

 * <li>Button1, Button2, Button3: <code>weightx&nbsp;=&nbsp;1.0</code>

 * <li>Button4: <code>weightx&nbsp;=&nbsp;1.0</code>,

 * <code>gridwidth&nbsp;=&nbsp;GridBagConstraints.REMAINDER</code>

 * <li>Button5: <code>gridwidth&nbsp;=&nbsp;GridBagConstraints.REMAINDER</code>

 * <li>Button6: <code>gridwidth&nbsp;=&nbsp;GridBagConstraints.RELATIVE</code>

 * <li>Button7: <code>gridwidth&nbsp;=&nbsp;GridBagConstraints.REMAINDER</code>

 * <li>Button8: <code>gridheight&nbsp;=&nbsp;2</code>,

 * <code>weighty&nbsp;=&nbsp;1.0</code>

 * <li>Button9, Button 10:

 * <code>gridwidth&nbsp;=&nbsp;GridBagConstraints.REMAINDER</code>

 * </ul>

 * <p>

 * Here is the code that implements the example shown above:

 *

 * <hr><blockquote><pre>

 * import java.awt.*;

 * import java.util.*;

 * import java.applet.Applet;

 *

 * public class GridBagEx1 extends Applet {

 *

 *     protected void makebutton(String name,

 *                               GridBagLayout gridbag,

 *                               GridBagConstraints c) {

 *         Button button = new Button(name);

 *         gridbag.setConstraints(button, c);

 *         add(button);

 *     }

 *

 *     public void init() {

 *         GridBagLayout gridbag = new GridBagLayout();

 *         GridBagConstraints c = new GridBagConstraints();

 *

 *         setFont(new Font("SansSerif", Font.PLAIN, 14));

 *         setLayout(gridbag);

 *

 *         c.fill = GridBagConstraints.BOTH;

 *         c.weightx = 1.0;

 *         makebutton("Button1", gridbag, c);

 *         makebutton("Button2", gridbag, c);

 *         makebutton("Button3", gridbag, c);

 *

 *         c.gridwidth = GridBagConstraints.REMAINDER; //end row

 *         makebutton("Button4", gridbag, c);

 *

 *         c.weightx = 0.0;                //reset to the default

 *         makebutton("Button5", gridbag, c); //another row

 *

 *         c.gridwidth = GridBagConstraints.RELATIVE; //next-to-last in row

 *         makebutton("Button6", gridbag, c);

 *

 *         c.gridwidth = GridBagConstraints.REMAINDER; //end row

 *         makebutton("Button7", gridbag, c);

 *

 *         c.gridwidth = 1;                //reset to the default

 *         c.gridheight = 2;

 *         c.weighty = 1.0;

 *         makebutton("Button8", gridbag, c);

 *

 *         c.weighty = 0.0;                //reset to the default

 *         c.gridwidth = GridBagConstraints.REMAINDER; //end row

 *         c.gridheight = 1;               //reset to the default

 *         makebutton("Button9", gridbag, c);

 *         makebutton("Button10", gridbag, c);

 *

 *         setSize(300, 100);

 *     }

 *

 *     public static void main(String args[]) {

 *         Frame f = new Frame("GridBag Layout Example");

 *         GridBagEx1 ex1 = new GridBagEx1();

 *

 *         ex1.init();

 *

 *         f.add("Center", ex1);

 *         f.pack();

 *         f.setSize(f.getPreferredSize());

 *         f.show();

 *     }

 * }

 * </pre></blockquote><hr>

 * <p>

 * @author Doug Stein

 * @author Bill Spitzak (orignial NeWS & OLIT implementation)

 * @see       java.awt.GridBagConstraints

 * @see       java.awt.GridBagLayoutInfo

 * @see       java.awt.ComponentOrientation

 * @since JDK1.0

 */

public class GridBagLayout implements LayoutManager2,

java.io.Serializable {

    static final int EMPIRICMULTIPLIER = 2;

    /**

     * This field is no longer used to reserve arrays and kept for backward

     * compatibility. Previously, this was

     * the maximum number of grid positions (both horizontal and

     * vertical) that could be laid out by the grid bag layout.

     * Current implementation doesn't impose any limits

     * on the size of a grid.

     */

    protected static final int MAXGRIDSIZE = 512;

    /**

     * The smallest grid that can be laid out by the grid bag layout.

     */

    protected static final int MINSIZE = 1;

    /**

     * The preferred grid size that can be laid out by the grid bag layout.

     */

    protected static final int PREFERREDSIZE = 2;

    /**

     * This hashtable maintains the association between

     * a component and its gridbag constraints.

     * The Keys in <code>comptable</code> are the components and the

     * values are the instances of <code>GridBagConstraints</code>.

     *

     * @serial

     * @see java.awt.GridBagConstraints

     */

    protected Hashtable<Component,GridBagConstraints> comptable;

    /**

     * This field holds a gridbag constraints instance

     * containing the default values, so if a component

     * does not have gridbag constraints associated with

     * it, then the component will be assigned a

     * copy of the <code>defaultConstraints</code>.

     *

     * @serial

     * @see #getConstraints(Component)

     * @see #setConstraints(Component, GridBagConstraints)

     * @see #lookupConstraints(Component)

     */

    protected GridBagConstraints defaultConstraints;

    /**

     * This field holds the layout information

     * for the gridbag.  The information in this field

     * is based on the most recent validation of the

     * gridbag.

     * If <code>layoutInfo</code> is <code>null</code>

     * this indicates that there are no components in

     * the gridbag or if there are components, they have

     * not yet been validated.

     *

     * @serial

     * @see #getLayoutInfo(Container, int)

     */

    protected GridBagLayoutInfo layoutInfo;

    /**

     * This field holds the overrides to the column minimum

     * width.  If this field is non-<code>null</code> the values are

     * applied to the gridbag after all of the minimum columns

     * widths have been calculated.

     * If columnWidths has more elements than the number of

     * columns, columns are added to the gridbag to match

     * the number of elements in columnWidth.

     *

     * @serial

     * @see #getLayoutDimensions()

     */

    public int columnWidths[];

    /**

     * This field holds the overrides to the row minimum

     * heights.  If this field is non-<code>null</code> the values are

     * applied to the gridbag after all of the minimum row

     * heights have been calculated.

     * If <code>rowHeights</code> has more elements than the number of

     * rows, rows are added to the gridbag to match

     * the number of elements in <code>rowHeights</code>.

     *

     * @serial

     * @see #getLayoutDimensions()

     */

    public int rowHeights[];

    /**

     * This field holds the overrides to the column weights.

     * If this field is non-<code>null</code> the values are

     * applied to the gridbag after all of the columns

     * weights have been calculated.

     * If <code>columnWeights[i]</code> &gt; weight for column i, then

     * column i is assigned the weight in <code>columnWeights[i]</code>.

     * If <code>columnWeights</code> has more elements than the number

     * of columns, the excess elements are ignored - they do

     * not cause more columns to be created.

     *

     * @serial

     */

    public double columnWeights[];

    /**

     * This field holds the overrides to the row weights.

     * If this field is non-<code>null</code> the values are

     * applied to the gridbag after all of the rows

     * weights have been calculated.

     * If <code>rowWeights[i]</code> &gt; weight for row i, then

     * row i is assigned the weight in <code>rowWeights[i]</code>.

     * If <code>rowWeights</code> has more elements than the number

     * of rows, the excess elements are ignored - they do

     * not cause more rows to be created.

     *

     * @serial

     */

    public double rowWeights[];

    /**

     * The component being positioned.  This is set before calling into

     * <code>adjustForGravity</code>.

     */

    private Component componentAdjusting;

    /**

     * Creates a grid bag layout manager.

     */

    public GridBagLayout () {

        comptable = new Hashtable<Component,GridBagConstraints>();

        defaultConstraints = new GridBagConstraints();

    }

    /**

     * Sets the constraints for the specified component in this layout.

     * @param       comp the component to be modified

     * @param       constraints the constraints to be applied

     */

    public void setConstraints(Component comp, GridBagConstraints constraints) {

        comptable.put(comp, (GridBagConstraints)constraints.clone());

    }

    /**

     * Gets the constraints for the specified component.  A copy of

     * the actual <code>GridBagConstraints</code> object is returned.

     * @param       comp the component to be queried

     * @return      the constraint for the specified component in this

     *                  grid bag layout; a copy of the actual constraint

     *                  object is returned

     */

    public GridBagConstraints getConstraints(Component comp) {

        GridBagConstraints constraints = comptable.get(comp);

        if (constraints == null) {

            setConstraints(comp, defaultConstraints);

            constraints = comptable.get(comp);

        }

        return (GridBagConstraints)constraints.clone();

    }

    /**

     * Retrieves the constraints for the specified component.

     * The return value is not a copy, but is the actual

     * <code>GridBagConstraints</code> object used by the layout mechanism.

     * <p>

     * If <code>comp</code> is not in the <code>GridBagLayout</code>,

     * a set of default <code>GridBagConstraints</code> are returned.

     * A <code>comp</code> value of <code>null</code> is invalid

     * and returns <code>null</code>.

     *

     * @param       comp the component to be queried

     * @return      the constraints for the specified component

     */

    protected GridBagConstraints lookupConstraints(Component comp) {

        GridBagConstraints constraints = comptable.get(comp);

        if (constraints == null) {

            setConstraints(comp, defaultConstraints);

            constraints = comptable.get(comp);

        }

        return constraints;

    }

    /**

     * Removes the constraints for the specified component in this layout

     * @param       comp the component to be modified

     */

    private void removeConstraints(Component comp) {

        comptable.remove(comp);

    }

    /**

     * Determines the origin of the layout area, in the graphics coordinate

     * space of the target container.  This value represents the pixel

     * coordinates of the top-left corner of the layout area regardless of

     * the <code>ComponentOrientation</code> value of the container.  This

     * is distinct from the grid origin given by the cell coordinates (0,0).

     * Most applications do not call this method directly.

     * @return     the graphics origin of the cell in the top-left

     *             corner of the layout grid

     * @see        java.awt.ComponentOrientation

     * @since      JDK1.1

     */

    public Point getLayoutOrigin () {

        Point origin = new Point(0,0);

        if (layoutInfo != null) {

            origin.x = layoutInfo.startx;

            origin.y = layoutInfo.starty;

        }

        return origin;

    }

    /**

     * Determines column widths and row heights for the layout grid.

     * <p>

     * Most applications do not call this method directly.

     * @return     an array of two arrays, containing the widths

     *                       of the layout columns and

     *                       the heights of the layout rows

     * @since      JDK1.1

     */

    public int [][] getLayoutDimensions () {

        if (layoutInfo == null)

            return new int[2][0];

        int dim[][] = new int [2][];

        dim[0] = new int[layoutInfo.width];

        dim[1] = new int[layoutInfo.height];

        System.arraycopy(layoutInfo.minWidth, 0, dim[0], 0, layoutInfo.width);

        System.arraycopy(layoutInfo.minHeight, 0, dim[1], 0, layoutInfo.height);

        return dim;

    }

    /**

     * Determines the weights of the layout grid's columns and rows.

     * Weights are used to calculate how much a given column or row

     * stretches beyond its preferred size, if the layout has extra

     * room to fill.

     * <p>

     * Most applications do not call this method directly.

     * @return      an array of two arrays, representing the

     *                    horizontal weights of the layout columns

     *                    and the vertical weights of the layout rows

     * @since       JDK1.1

     */

    public double [][] getLayoutWeights () {

        if (layoutInfo == null)

            return new double[2][0];

        double weights[][] = new double [2][];

        weights[0] = new double[layoutInfo.width];

        weights[1] = new double[layoutInfo.height];

        System.arraycopy(layoutInfo.weightX, 0, weights[0], 0, layoutInfo.width);

        System.arraycopy(layoutInfo.weightY, 0, weights[1], 0, layoutInfo.height);

        return weights;

    }

    /**

     * Determines which cell in the layout grid contains the point

     * specified by <code>(x,&nbsp;y)</code>. Each cell is identified

     * by its column index (ranging from 0 to the number of columns

     * minus 1) and its row index (ranging from 0 to the number of

     * rows minus 1).

     * <p>

     * If the <code>(x,&nbsp;y)</code> point lies

     * outside the grid, the following rules are used.

     * The column index is returned as zero if <code>x</code> lies to the

     * left of the layout for a left-to-right container or to the right of

     * the layout for a right-to-left container.  The column index is returned

     * as the number of columns if <code>x</code> lies

     * to the right of the layout in a left-to-right container or to the left

     * in a right-to-left container.

     * The row index is returned as zero if <code>y</code> lies above the

     * layout, and as the number of rows if <code>y</code> lies

     * below the layout.  The orientation of a container is determined by its

     * <code>ComponentOrientation</code> property.

     * @param      x    the <i>x</i> coordinate of a point

     * @param      y    the <i>y</i> coordinate of a point

     * @return     an ordered pair of indexes that indicate which cell

     *             in the layout grid contains the point

     *             (<i>x</i>,&nbsp;<i>y</i>).

     * @see        java.awt.ComponentOrientation

     * @since      JDK1.1

     */

    public Point location(int x, int y) {

        Point loc = new Point(0,0);

        int i, d;

        if (layoutInfo == null)

            return loc;

        d = layoutInfo.startx;

        if (!rightToLeft) {

            for (i=0; i<layoutInfo.width; i++) {

                d += layoutInfo.minWidth[i];

                if (d > x)

                    break;

            }

        } else {

            for (i=layoutInfo.width-1; i>=0; i--) {

                if (d > x)

                    break;

                d += layoutInfo.minWidth[i];

            }

            i++;

        }

        loc.x = i;

        d = layoutInfo.starty;

        for (i=0; i<layoutInfo.height; i++) {

            d += layoutInfo.minHeight[i];

            if (d > y)

                break;

        }

        loc.y = i;

        return loc;

    }

    /**

     * Has no effect, since this layout manager does not use a per-component string.

     */

    public void addLayoutComponent(String name, Component comp) {

    }

    /**

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

     * <code>constraints</code> object.  Note that constraints

     * are mutable and are, therefore, cloned when cached.

     *

     * @param      comp         the component to be added

     * @param      constraints  an object that determines how

     *                          the component is added to the layout

     * @exception IllegalArgumentException if <code>constraints</code>

     *            is not a <code>GridBagConstraint</code>

     */

    public void addLayoutComponent(Component comp, Object constraints) {

        if (constraints instanceof GridBagConstraints) {

            setConstraints(comp, (GridBagConstraints)constraints);

        } else if (constraints != null) {

            throw new IllegalArgumentException("cannot add to layout: constraints must be a GridBagConstraint");

        }

    }

    /**

     * Removes the specified component from this layout.

     * <p>

     * Most applications do not call this method directly.

     * @param    comp   the component to be removed.

     * @see      java.awt.Container#remove(java.awt.Component)

     * @see      java.awt.Container#removeAll()

     */

    public void removeLayoutComponent(Component comp) {

        removeConstraints(comp);

    }

    /**

     * Determines the preferred size of the <code>parent</code>

     * container using this grid bag layout.

     * <p>

     * Most applications do not call this method directly.

     *

     * @param     parent   the container in which to do the layout

     * @see       java.awt.Container#getPreferredSize

     * @return the preferred size of the <code>parent</code>

     *  container

     */

    public Dimension preferredLayoutSize(Container parent) {

        GridBagLayoutInfo info = getLayoutInfo(parent, PREFERREDSIZE);

        return getMinSize(parent, info);

    }

    /**

     * Determines the minimum size of the <code>parent</code> container

     * using this grid bag layout.

     * <p>

     * Most applications do not call this method directly.

     * @param     parent   the container in which to do the layout

     * @see       java.awt.Container#doLayout

     * @return the minimum size of the <code>parent</code> container

     */

    public Dimension minimumLayoutSize(Container parent) {

        GridBagLayoutInfo info = getLayoutInfo(parent, MINSIZE);

        return getMinSize(parent, info);

    }

    /**

     * Returns the maximum dimensions for this layout given the components

     * in the specified target container.

     * @param target the container which needs to be laid out

     * @see Container

     * @see #minimumLayoutSize(Container)

     * @see #preferredLayoutSize(Container)

     * @return the maximum dimensions for this layout

     */

    public Dimension maximumLayoutSize(Container target) {

        return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);

    }

    /**

     * 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.

     * <p>

     * @return the value <code>0.5f</code> to indicate centered

     */

    public float getLayoutAlignmentX(Container parent) {

        return 0.5f;

    }

    /**

     * 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.

     * <p>

     * @return the value <code>0.5f</code> to indicate centered

     */

    public float getLayoutAlignmentY(Container parent) {

        return 0.5f;

    }

    /**

     * Invalidates the layout, indicating that if the layout manager

     * has cached information it should be discarded.

     */

    public void invalidateLayout(Container target) {

    }

    /**

     * Lays out the specified container using this grid bag layout.

     * This method reshapes components in the specified container in

     * order to satisfy the constraints of this <code>GridBagLayout</code>

     * object.

     * <p>

     * Most applications do not call this method directly.

     * @param parent the container in which to do the layout

     * @see java.awt.Container

     * @see java.awt.Container#doLayout

     */

    public void layoutContainer(Container parent) {

        arrangeGrid(parent);

    }

    /**

     * Returns a string representation of this grid bag layout's values.

     * @return     a string representation of this grid bag layout.

     */

    public String toString() {

        return getClass().getName();

    }

    /**

     * Print the layout information.  Useful for debugging.

     */

    /* DEBUG

     *

     *  protected void dumpLayoutInfo(GridBagLayoutInfo s) {

     *    int x;

     *

     *    System.out.println("Col\tWidth\tWeight");

     *    for (x=0; x<s.width; x++) {

     *      System.out.println(x + "\t" +

     *                   s.minWidth[x] + "\t" +

     *                   s.weightX[x]);

     *    }

     *    System.out.println("Row\tHeight\tWeight");

     *    for (x=0; x<s.height; x++) {

     *      System.out.println(x + "\t" +

     *                   s.minHeight[x] + "\t" +

     *                   s.weightY[x]);

     *    }

     *  }

     */

    /**

     * Print the layout constraints.  Useful for debugging.

     */

    /* DEBUG

     *

     *  protected void dumpConstraints(GridBagConstraints constraints) {

     *    System.out.println(

     *                 "wt " +

     *                 constraints.weightx +

     *                 " " +

     *                 constraints.weighty +

     *                 ", " +

     *

     *                 "box " +

     *                 constraints.gridx +

     *                 " " +

     *                 constraints.gridy +

     *                 " " +

     *                 constraints.gridwidth +

     *                 " " +

     *                 constraints.gridheight +

     *                 ", " +

     *

     *                 "min " +

     *                 constraints.minWidth +

     *                 " " +

     *                 constraints.minHeight +

     *                 ", " +

     *

     *                 "pad " +

     *                 constraints.insets.bottom +

     *                 " " +

     *                 constraints.insets.left +

     *                 " " +

     *                 constraints.insets.right +

     *                 " " +

     *                 constraints.insets.top +

     *                 " " +

     *                 constraints.ipadx +

     *                 " " +

     *                 constraints.ipady);

     *  }

     */

    /**

     * Fills in an instance of <code>GridBagLayoutInfo</code> for the

     * current set of managed children. This requires three passes through the

     * set of children:

     *

     * <ol>

     * <li>Figure out the dimensions of the layout grid.

     * <li>Determine which cells the components occupy.

     * <li>Distribute the weights and min sizes among the rows/columns.

     * </ol>

     *

     * This also caches the minsizes for all the children when they are

     * first encountered (so subsequent loops don't need to ask again).

     * <p>

     * This method should only be used internally by

     * <code>GridBagLayout</code>.

     *

     * @param parent  the layout container

     * @param sizeflag either <code>PREFERREDSIZE</code> or

     *   <code>MINSIZE</code>

     * @return the <code>GridBagLayoutInfo</code> for the set of children

     * @since 1.4

     */

    protected GridBagLayoutInfo getLayoutInfo(Container parent, int sizeflag) {

        return GetLayoutInfo(parent, sizeflag);

    }

    /*

     * Calculate maximum array sizes to allocate arrays without ensureCapacity

     * we may use preCalculated sizes in whole class because of upper estimation of

     * maximumArrayXIndex and maximumArrayYIndex.

     */

    private long[]  preInitMaximumArraySizes(Container parent){

        Component components[] = parent.getComponents();

        Component comp;

        GridBagConstraints constraints;

        int curX, curY;

        int curWidth, curHeight;

        int preMaximumArrayXIndex = 0;

        int preMaximumArrayYIndex = 0;

        long [] returnArray = new long[2];

        for (int compId = 0 ; compId < components.length ; compId++) {

            comp = components[compId];

            if (!comp.isVisible()) {

                continue;

            }

            constraints = lookupConstraints(comp);

            curX = constraints.gridx;

            curY = constraints.gridy;

            curWidth = constraints.gridwidth;

            curHeight = constraints.gridheight;

            // -1==RELATIVE, means that column|row equals to previously added component,

            // since each next Component with gridx|gridy == RELATIVE starts from

            // previous position, so we should start from previous component which

            // already used in maximumArray[X|Y]Index calculation. We could just increase

            // maximum by 1 to handle situation when component with gridx=-1 was added.

            if (curX < 0){

                curX = ++preMaximumArrayYIndex;

            }

            if (curY < 0){

                curY = ++preMaximumArrayXIndex;

            }

            // gridwidth|gridheight may be equal to RELATIVE (-1) or REMAINDER (0)

            // in any case using 1 instead of 0 or -1 should be sufficient to for

            // correct maximumArraySizes calculation

            if (curWidth <= 0){

                curWidth = 1;

            }

            if (curHeight <= 0){

                curHeight = 1;

            }

            preMaximumArrayXIndex = Math.max(curY + curHeight, preMaximumArrayXIndex);

            preMaximumArrayYIndex = Math.max(curX + curWidth, preMaximumArrayYIndex);

        } //for (components) loop

        // Must specify index++ to allocate well-working arrays.

        /* fix for 4623196.

         * now return long array instead of Point

         */

        returnArray[0] = preMaximumArrayXIndex;

        returnArray[1] = preMaximumArrayYIndex;

        return returnArray;

    } //PreInitMaximumSizes

    /**

     * This method is obsolete and supplied for backwards

     * compatibility only; new code should call {@link

     * #getLayoutInfo(java.awt.Container, int) getLayoutInfo} instead.

     * This method is the same as <code>getLayoutInfo</code>;

     * refer to <code>getLayoutInfo</code> for details on parameters

     * and return value.

     */

    protected GridBagLayoutInfo GetLayoutInfo(Container parent, int sizeflag) {

        synchronized (parent.getTreeLock()) {

            GridBagLayoutInfo r;

            Component comp;

            GridBagConstraints constraints;

            Dimension d;

            Component components[] = parent.getComponents();

            // Code below will address index curX+curWidth in the case of yMaxArray, weightY

            // ( respectively curY+curHeight for xMaxArray, weightX ) where

            //  curX in 0 to preInitMaximumArraySizes.y

            // Thus, the maximum index that could

            // be calculated in the following code is curX+curX.

            // EmpericMultier equals 2 because of this.

            int layoutWidth, layoutHeight;

            int []xMaxArray;

            int []yMaxArray;

            int compindex, i, k, px, py, pixels_diff, nextSize;

            int curX = 0; // constraints.gridx

            int curY = 0; // constraints.gridy

            int curWidth = 1;  // constraints.gridwidth

            int curHeight = 1;  // constraints.gridheight

            int curRow, curCol;

            double weight_diff, weight;

            int maximumArrayXIndex = 0;

            int maximumArrayYIndex = 0;

            int anchor;

            /*

             * Pass #1

             *

             * Figure out the dimensions of the layout grid (use a value of 1 for

             * zero or negative widths and heights).

             */

            layoutWidth = layoutHeight = 0;

            curRow = curCol = -1;

            long [] arraySizes = preInitMaximumArraySizes(parent);

            /* fix for 4623196.

             * If user try to create a very big grid we can

             * get NegativeArraySizeException because of integer value

             * overflow (EMPIRICMULTIPLIER*gridSize might be more then Integer.MAX_VALUE).

             * We need to detect this situation and try to create a

             * grid with Integer.MAX_VALUE size instead.

             */

            maximumArrayXIndex = (EMPIRICMULTIPLIER * arraySizes[0] > Integer.MAX_VALUE )? Integer.MAX_VALUE : EMPIRICMULTIPLIER*(int)arraySizes[0];

            maximumArrayYIndex = (EMPIRICMULTIPLIER * arraySizes[1] > Integer.MAX_VALUE )? Integer.MAX_VALUE : EMPIRICMULTIPLIER*(int)arraySizes[1];

            if (rowHeights != null){

                maximumArrayXIndex = Math.max(maximumArrayXIndex, rowHeights.length);

            }

            if (columnWidths != null){

                maximumArrayYIndex = Math.max(maximumArrayYIndex, columnWidths.length);

            }

            xMaxArray = new int[maximumArrayXIndex];

            yMaxArray = new int[maximumArrayYIndex];

            boolean hasBaseline = false;

            for (compindex = 0 ; compindex < components.length ; compindex++) {

                comp = components[compindex];

                if (!comp.isVisible())

                    continue;

                constraints = lookupConstraints(comp);

                curX = constraints.gridx;

                curY = constraints.gridy;

                curWidth = constraints.gridwidth;

                if (curWidth <= 0)

                    curWidth = 1;

                curHeight = constraints.gridheight;

                if (curHeight <= 0)

                    curHeight = 1;

                /* If x or y is negative, then use relative positioning: */

                if (curX < 0 && curY < 0) {

                    if (curRow >= 0)

                        curY = curRow;

                    else if (curCol >= 0)

                        curX = curCol;

                    else

                        curY = 0;

                }

                if (curX < 0) {

                    px = 0;

                    for (i = curY; i < (curY + curHeight); i++) {

                        px = Math.max(px, xMaxArray[i]);

                    }

                    curX = px - curX - 1;

                    if(curX < 0)

                        curX = 0;

                }

                else if (curY < 0) {

                    py = 0;

                    for (i = curX; i < (curX + curWidth); i++) {

                        py = Math.max(py, yMaxArray[i]);

                    }

                    curY = py - curY - 1;

                    if(curY < 0)

                        curY = 0;

                }

                /* Adjust the grid width and height

                 *  fix for 5005945: unneccessary loops removed

                 */

                px = curX + curWidth;

                if (layoutWidth < px) {

                    layoutWidth = px;

                }

                py = curY + curHeight;

                if (layoutHeight < py) {

                    layoutHeight = py;

                }

                /* Adjust xMaxArray and yMaxArray */

                for (i = curX; i < (curX + curWidth); i++) {

                    yMaxArray[i] =py;

                }

                for (i = curY; i < (curY + curHeight); i++) {

                    xMaxArray[i] = px;

                }

                /* Cache the current slave's size. */

                if (sizeflag == PREFERREDSIZE)

                    d = comp.getPreferredSize();

                else

                    d = comp.getMinimumSize();

                constraints.minWidth = d.width;

                constraints.minHeight = d.height;

                if (calculateBaseline(comp, constraints, d)) {

                    hasBaseline = true;

                }

                /* Zero width and height must mean that this is the last item (or

                 * else something is wrong). */

                if (constraints.gridheight == 0 && constraints.gridwidth == 0)

                    curRow = curCol = -1;

                /* Zero width starts a new row */

                if (constraints.gridheight == 0 && curRow < 0)

                    curCol = curX + curWidth;

                /* Zero height starts a new column */

                else if (constraints.gridwidth == 0 && curCol < 0)

                    curRow = curY + curHeight;

            } //for (components) loop

            /*

             * Apply minimum row/column dimensions

             */

            if (columnWidths != null && layoutWidth < columnWidths.length)

                layoutWidth = columnWidths.length;

            if (rowHeights != null && layoutHeight < rowHeights.length)

                layoutHeight = rowHeights.length;

            r = new GridBagLayoutInfo(layoutWidth, layoutHeight);

            /*

             * Pass #2

             *

             * Negative values for gridX are filled in with the current x value.

             * Negative values for gridY are filled in with the current y value.

             * Negative or zero values for gridWidth and gridHeight end the current

             *  row or column, respectively.

             */

            curRow = curCol = -1;

            Arrays.fill(xMaxArray, 0);

            Arrays.fill(yMaxArray, 0);

            int[] maxAscent = null;

            int[] maxDescent = null;

            short[] baselineType = null;

            if (hasBaseline) {

                r.maxAscent = maxAscent = new int[layoutHeight];

                r.maxDescent = maxDescent = new int[layoutHeight];

                r.baselineType = baselineType = new short[layoutHeight];

                r.hasBaseline = true;

            }

            for (compindex = 0 ; compindex < components.length ; compindex++) {

                comp = components[compindex];

                if (!comp.isVisible())

                    continue;

                constraints = lookupConstraints(comp);

                curX = constraints.gridx;

                curY = constraints.gridy;

                curWidth = constraints.gridwidth;

                curHeight = constraints.gridheight;

                /* If x or y is negative, then use relative positioning: */

                if (curX < 0 && curY < 0) {

                    if(curRow >= 0)

                        curY = curRow;

                    else if(curCol >= 0)

                        curX = curCol;

                    else

                        curY = 0;

                }

                if (curX < 0) {

                    if (curHeight <= 0) {

                        curHeight += r.height - curY;

                        if (curHeight < 1)

                            curHeight = 1;

                    }

                    px = 0;

                    for (i = curY; i < (curY + curHeight); i++)

                        px = Math.max(px, xMaxArray[i]);

                    curX = px - curX - 1;

                    if(curX < 0)

                        curX = 0;

                }

                else if (curY < 0) {

                    if (curWidth <= 0) {

                        curWidth += r.width - curX;

                        if (curWidth < 1)

                            curWidth = 1;

                    }

                    py = 0;

                    for (i = curX; i < (curX + curWidth); i++){

                        py = Math.max(py, yMaxArray[i]);

                    }

                    curY = py - curY - 1;

                    if(curY < 0)

                        curY = 0;

                }

                if (curWidth <= 0) {

                    curWidth += r.width - curX;

                    if (curWidth < 1)

                        curWidth = 1;

                }

                if (curHeight <= 0) {

                    curHeight += r.height - curY;

                    if (curHeight < 1)

                        curHeight = 1;

                }

                px = curX + curWidth;