/*

 * Copyright (c) 1995, Oracle and/or its affiliates. All rights reserved.

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

 *

 * 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

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

 *

 * 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.

 *

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

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 */

package sun.awt;

import java.awt.*;

import java.util.BitSet;

/**

 * A layout manager for a container that lays out grids.  Allows setting

 * the relative sizes of rows and columns.

 *

 * @author Herb Jellinek

 */

public class VariableGridLayout extends GridLayout {

    BitSet rowsSet = new BitSet();

    double rowFractions[] = null;

    BitSet colsSet = new BitSet();

    double colFractions[] = null;

    int rows;

    int cols;

    int hgap;

    int vgap;

    /**

     * Creates a grid layout with the specified rows and specified columns.

     * @param rows the rows

     * @param cols the columns

     */

    public VariableGridLayout(int rows, int cols) {

        this(rows, cols, 0, 0);

        if (rows != 0) {

            rowsSet = new BitSet(rows);

            stdRowFractions(rows);

        }

        if (cols != 0) {

            colsSet = new BitSet(cols);

            stdColFractions(cols);

        }

    }

    /**

     * Creates a grid layout with the specified rows, columns,

     * horizontal gap, and vertical gap.

     * @param rows the rows

     * @param cols the columns

     * @param hgap the horizontal gap variable

     * @param vgap the vertical gap variable

     * @exception IllegalArgumentException If the rows and columns are invalid.

     */

    public VariableGridLayout(int rows, int cols, int hgap, int vgap) {

        super(rows, cols, hgap, vgap);

        this.rows = rows;

        this.cols = cols;

        this.hgap = hgap;

        this.vgap = vgap;

        if (rows != 0) {

            rowsSet = new BitSet(rows);

            stdRowFractions(rows);

        }

        if (cols != 0) {

            colsSet = new BitSet(cols);

            stdColFractions(cols);

        }

    }

    void stdRowFractions(int nrows) {

        rowFractions = new double[nrows];

        for (int i = 0; i < nrows; i++) {

            rowFractions[i] = 1.0 / nrows;

        }

    }

    void stdColFractions(int ncols) {

        colFractions = new double[ncols];

        for (int i = 0; i < ncols; i++) {

            colFractions[i] = 1.0 / ncols;

        }

    }

    public void setRowFraction(int rowNum, double fraction) {

        rowsSet.set(rowNum);

        rowFractions[rowNum] = fraction;

    }

    public void setColFraction(int colNum, double fraction) {

        colsSet.set(colNum);

        colFractions[colNum] = fraction;

    }

    public double getRowFraction(int rowNum) {

        return rowFractions[rowNum];

    }

    public double getColFraction(int colNum) {

        return colFractions[colNum];

    }

    void allocateExtraSpace(double vec[], BitSet userSet) {

        // collect the space that's been explicitly allocated...

        double total = 0.0;

        int unallocated = 0;

        int i;

        for (i = 0; i < vec.length; i++) {

            if (userSet.get(i)) {

                total += vec[i];

            } else {

                unallocated++;

            }

        }

        // ... then spread the extra space

        if (unallocated != 0) {

            double space = (1.0 - total) / unallocated;

            for (i = 0; i < vec.length; i++) {

                if (!userSet.get(i)) {

                    vec[i] = space;

                    userSet.set(i);

                }

            }

        }

    }

    void allocateExtraSpace() {

        allocateExtraSpace(rowFractions, rowsSet);

        allocateExtraSpace(colFractions, colsSet);

    }

    /**

     * Lays out the container in the specified panel.

     * @param parent the specified component being laid out

     * @see Container

     */

    public void layoutContainer(Container parent) {

        Insets insets = parent.insets();

        int ncomponents = parent.countComponents();

        int nrows = rows;

        int ncols = cols;

        if (nrows > 0) {

            ncols = (ncomponents + nrows - 1) / nrows;

        } else {

            nrows = (ncomponents + ncols - 1) / ncols;

        }

        if (rows == 0) {

            stdRowFractions(nrows);

        }

        if (cols == 0) {

            stdColFractions(ncols);

        }

        Dimension size = parent.size();

        int w = size.width - (insets.left + insets.right);

        int h = size.height - (insets.top + insets.bottom);

        w = (w - (ncols - 1) * hgap);

        h = (h - (nrows - 1) * vgap);

        allocateExtraSpace();

        for (int c = 0, x = insets.left ; c < ncols ; c++) {

            int colWidth = (int)(getColFraction(c) * w);

            for (int r = 0, y = insets.top ; r < nrows ; r++) {

                int i = r * ncols + c;

                int rowHeight = (int)(getRowFraction(r) * h);

                if (i < ncomponents) {

                    parent.getComponent(i).reshape(x, y, colWidth, rowHeight);

                }

                y += rowHeight + vgap;

            }

            x += colWidth + hgap;

        }

    }

    static String fracsToString(double array[]) {

        String result = "["+array.length+"]";

        for (int i = 0; i < array.length; i++) {

            result += "<"+array[i]+">";

        }

        return result;

    }

    /**

     * Returns the String representation of this VariableGridLayout's values.

     */

    public String toString() {

        return getClass().getName() + "[hgap=" + hgap + ",vgap=" + vgap +

                                       ",rows=" + rows + ",cols=" + cols +

                                       ",rowFracs=" +

                                       fracsToString(rowFractions) +

                                       ",colFracs=" +

                                       fracsToString(colFractions) + "]";

    }

}