import java.awt.*;

/*
 *  StackLayout.java (Market View Java Applet)
 *  Copyright (C) 1996 Softbear Inc. (info@softbear.com)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
*/


/**
 * A layoutManager which stacks components one on top of the other,
 * regardless of their size.
 * @version Improved by Mark Grand
*/
public class StackLayout implements LayoutManager {
    private int vgap;
    private static final int DEFAULT_VGAP = 3;

    /**
     * Create a StackLayout with a default vertical gap.
     */
    public StackLayout() {
        this(DEFAULT_VGAP);
    } // StackLayout()

    /**
     * Create a StackLayout with the specified vertical gap.
     * @param vgap the number of pixels to leave between Components.
     */
    public StackLayout(int vgap) {
        this.vgap = vgap;
    } // StackLayout(int)

    /**
     * Adds the specified component with the specified name to
     * the layout.
     * <p>
     * The implementation of this method does not actually do anything
     * because this LayoutManager uses the Container's information
     * about its contents.
     */
    public void addLayoutComponent(String name, Component comp) {}

    /**
     * Removes the specified component from the layout.
     * @param comp the component ot be removed
     * <p>
     * The implementation of this method does not actually do anything
     * because this LayoutManager uses the Container's information
     * about its contents.
     */
    public void removeLayoutComponent(Component comp) {
    } // removeLayoutComponent(Component)

    /**
     * Calculates the preferred size dimensions for the specified 
     * panel given the components in the specified parent container.
     * @param parent the component to be laid out
     * @see #minimumLayoutSize
     */
    public Dimension preferredLayoutSize(Container parent) {
        Insets	insets = parent.insets();
        int	ncomponents = parent.countComponents();
        int	w = 0;
        int	h = 0;

        for (int i = 0 ; i < ncomponents ; i++) {
            Component comp = parent.getComponent(i);
            if (!comp.isVisible())
              continue;
            Dimension d = comp.preferredSize();
            if (w < d.width) {
                w = d.width;
            } // if
            h += d.height;
            if (i != 0) {
                h += this.vgap;
            } // if
        } // for
        return new Dimension(insets.left + insets.right + w,
                             insets.top + insets.bottom + h);
    } // preferredLayoutSize(Container)

    /** 
     * Calculates the minimum size dimensions for the specified 
     * panel given the components in the specified parent container.
     * @param parent the component to be laid out
     * @see #preferredLayoutSize
     */
    public Dimension minimumLayoutSize(Container parent) {
        Insets	insets = parent.insets();
        int	ncomponents = parent.countComponents();
        int	w = 0;
        int	h = 0;

        for (int i = 0 ; i < ncomponents ; i++) {
            Component comp = parent.getComponent(i);
            if (!comp.isVisible())
              continue;
            Dimension d = comp.minimumSize();
            if (w < d.width) {
                w = d.width;
            } // if
            h += d.height;
            if (i != 0) {
                h += this.vgap;
            } // if
        } // for
        return new Dimension(insets.left + insets.right + w,
                             insets.top + insets.bottom + h);
    }

    /** 
     * Lays out the specified container.
     * @param parent the Container to lay out 
     */
    public void layoutContainer(Container parent) {
        int availableHeight;    // Actual height available layout.
        Insets insets = parent.insets();
        int x = insets.left;
        int y = insets.top;
        Dimension parentSize = parent.size();
        int usableWidth = parentSize.width - insets.left - insets.right;

        int ncomponents = parent.countComponents();
        availableHeight = parentSize.height-insets.top-insets.bottom;
        boolean useMinimum;
        useMinimum = preferredLayoutSize(parent).height<availableHeight;
        for (int i = 0; i < ncomponents; ++i) {
            Component comp = parent.getComponent(i);
            if (!comp.isVisible())
              continue;
            Dimension d = useMinimum ? comp.minimumSize()
                                     : comp.preferredSize();
            comp.reshape(x, y, usableWidth, d.height);
            y += (d.height + this.vgap);
        }
    } // layoutContainer(Container)
} // class StackLayout