/*
 *    Geotoolkit - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2012 Geomatys
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library 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
 *    Lesser General Public License for more details.
 */
package org.geotoolkit.gui.swing.util;

import java.awt.*;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;

/**
 * WrapLayout
 * @author Fabien Rétif (Geomatys)
 */

public class WrapLayout extends FlowLayout {
    
    public WrapLayout() {
        super();
    }

    
    public WrapLayout(int align) {
        super(align);
    }

    
    public WrapLayout(int align, int hgap, int vgap) {
        super(align, hgap, vgap);
    }

   
    @Override
    public Dimension preferredLayoutSize(Container target) {
        return layoutSize(target, true);
    }

    @Override
    public Dimension minimumLayoutSize(Container target) {
        Dimension minimum = layoutSize(target, false);
        minimum.width -= (getHgap() + 1);
        return minimum;
    }

    
    private Dimension layoutSize(Container target, boolean preferred) {
        synchronized (target.getTreeLock()) {
            //  Each row must fit with the width allocated to the containter.
            //  When the container width = 0, the preferred width of the container
            //  has not yet been calculated so lets ask for the maximum.

            int targetWidth = target.getSize().width;

            if (targetWidth == 0) {
                targetWidth = Integer.MAX_VALUE;
            }

            int hgap = getHgap();
            int vgap = getVgap();
            Insets insets = target.getInsets();
            int horizontalInsetsAndGap = insets.left + insets.right + (hgap * 2);
            int maxWidth = targetWidth - horizontalInsetsAndGap;

            //  Fit components into the allowed width

            Dimension dim = new Dimension(0, 0);
            int rowWidth = 0;
            int rowHeight = 0;

            int nmembers = target.getComponentCount();

            for (int i = 0; i < nmembers; i++) {
                Component m = target.getComponent(i);

                if (m.isVisible()) {
                    Dimension d = preferred ? m.getPreferredSize() : m.getMinimumSize();

                    //  Can't add the component to current row. Start a new row.

                    if (rowWidth + d.width > maxWidth) {
                        addRow(dim, rowWidth, rowHeight);
                        rowWidth = 0;
                        rowHeight = 0;
                    }

                    //  Add a horizontal gap for all components after the first

                    if (rowWidth != 0) {
                        rowWidth += hgap;
                    }

                    rowWidth += d.width;
                    rowHeight = Math.max(rowHeight, d.height);
                }
            }

            addRow(dim, rowWidth, rowHeight);

            dim.width += horizontalInsetsAndGap;
            dim.height += insets.top + insets.bottom + vgap * 2;
           

            Container scrollPane = SwingUtilities.getAncestorOfClass(JScrollPane.class, target);

            if (scrollPane != null) {
                dim.width -= (hgap + 1);
            }

            return dim;
        }
    }

  
    private void addRow(Dimension dim, int rowWidth, int rowHeight) {
        dim.width = Math.max(dim.width, rowWidth);

        if (dim.height > 0) {
            dim.height += getVgap();
        }

        dim.height += rowHeight;
    }
}