g2textmeasurer.java

来自「JfreeChart 常用图表例子」· Java 代码 · 共 88 行

/* ========================================================================
 * JCommon : a free general purpose class library for the Java(tm) platform
 * ========================================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 * 
 * Project Info:  http://www.jfree.org/jcommon/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.]
 * 
 * -------------------
 * G2TextMeasurer.java
 * -------------------
 * (C) Copyright 2004, 2005, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: G2TextMeasurer.java,v 1.3 2005/06/01 14:12:29 taqua Exp $
 *
 * Changes
 * -------
 * 07-Jan-2004 : Version 1 (DG);
 *
 */
 
package org.jfree.text;

import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;

/**
 * A {@link TextMeasurer} based on a {@link Graphics2D}.
 *
 * @author David Gilbert
 */
public class G2TextMeasurer implements TextMeasurer {

    /** The graphics device. */
    private Graphics2D g2;
    
    /**
     * Creates a new text measurer.
     * 
     * @param g2  the graphics device.
     */
    public G2TextMeasurer(final Graphics2D g2) {
        this.g2 = g2;
    }

    /**
     * Returns the string width.
     * 
     * @param text  the text.
     * @param start  the index of the first character to measure.
     * @param end  the index of the last character to measure.
     * 
     * @return The string width.
     */
    public float getStringWidth(final String text, 
                                final int start, final int end) {
        final FontMetrics fm = this.g2.getFontMetrics();
        final Rectangle2D bounds = TextUtilities.getTextBounds(
            text.substring(start, end), this.g2, fm
        );
        final float result = (float) bounds.getWidth();
        return result;
    }
    
}