standardlegenditemlayout.java

jfreechart安装程序和使用说明

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * 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;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * -----------------------------
 * StandardLegendItemLayout.java
 * -----------------------------
 * (C) Copyright 2002-2004, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: StandardLegendItemLayout.java,v 1.1 2004/08/31 14:26:08 mungady Exp $
 *
 * Changes
 * -------
 * 07-Feb-2002 : Version 1 (DG);
 * 02-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 *
 */

package org.jfree.chart;

import java.util.Iterator;

/**
 * A class for arranging legend items.
 *
 */
public class StandardLegendItemLayout implements LegendItemLayout {

    /** Useful constant for vertical orientation. */
    public static final int VERTICAL = 0;

    /** Useful constant for horizontal orientation. */
    public static final int HORIZONTAL = 1;

    /** The orientation of the layout (HORIZONTAL or VERTICAL). */
    private int orientation;

    /** A constraint on one of the dimesions in the layout. */
    private double dimension;

    /**
     * Constructs a new layout class for legend items.
     *
     * @param orientation  the orientation of the layout (HORIZONTAL or VERTICAL).
     * @param dimension  the constrained dimension.
     */
    public StandardLegendItemLayout(int orientation, double dimension) {

        this.orientation = orientation;
        this.dimension = dimension;

    }

    /**
     * Performs a layout on the items in the collection.
     *
     * @param collection  the collection to be laid out.
     */
    public void layoutLegendItems(LegendItemCollection collection) {

        if (this.orientation == HORIZONTAL) {
            doHorizontalLayout(collection);
        }
        else if (this.orientation == VERTICAL) {
            doVerticalLayout(collection);
        }

    }

    /**
     * Lays out the items horizontally, with a constraint on the width.
     * @param collection    The collection to be laid out.
     */
    private void doHorizontalLayout(LegendItemCollection collection) {

        // run through the items in the collection and set their coordinates
        // relative to (0, 0)
        Iterator iterator = collection.iterator();

       // int rowCount = 0;
       // double totalHeight = 0.0;
        boolean first = true;
        double currentRowX = 0.0;
        double currentRowY = 0.0;
        double currentRowHeight = 0.0;

        while (iterator.hasNext()) {
            DrawableLegendItem item = (DrawableLegendItem) iterator.next();
            if ((first) || (item.getWidth() < (this.dimension - currentRowX))) {
                item.setX(currentRowX);
                item.setY(currentRowY);
                currentRowX = currentRowX + item.getWidth();
                currentRowHeight = Math.max(currentRowHeight, item.getHeight());
                first = false;
            }
            else {  // start new row
                currentRowY = currentRowY + currentRowHeight;
                currentRowHeight = item.getHeight();
                item.setX(0.0);
                currentRowX = item.getWidth();
            }

        }

    }

    /**
     * Lays out the items vertically, with a constraint on the height.
     * @param collection    The collection to be laid out.
     */
    private void doVerticalLayout(LegendItemCollection collection) {

        // run through the items in the collection and set their coordinates
        // relative to (0, 0)
        Iterator iterator = collection.iterator();

        //int columnCount = 0;
        //double totalWidth = 0.0;
        boolean first = true;
        double currentColumnX = 0.0;
        double currentColumnY = 0.0;
        double currentColumnWidth = 0.0;

        while (iterator.hasNext()) {
            DrawableLegendItem item = (DrawableLegendItem) iterator.next();
            if ((first) || (item.getHeight() < (this.dimension - currentColumnY))) {
                item.setX(currentColumnX);
                item.setY(currentColumnY);
                currentColumnY = currentColumnY + item.getHeight();
                currentColumnWidth = Math.max(currentColumnWidth, item.getWidth());
                first = false;
            }
            else {  // start new column
                currentColumnX = currentColumnX + currentColumnWidth;
                currentColumnWidth = item.getWidth();
                item.setY(0.0);
                currentColumnY = item.getHeight();
            }

        }
    }

}