textutilities.java

该源代码为一些通用的程序

/* ========================================================================
 * JCommon : a free general purpose class library for the Java(tm) platform
 * ========================================================================
 *
 * (C) Copyright 2000-2006, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 * 
 * ------------------
 * TextUtilities.java
 * ------------------
 * (C) Copyright 2004-2006, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: TextUtilities.java,v 1.19 2006/01/06 10:21:31 mungady Exp $
 *
 * Changes
 * -------
 * 07-Jan-2004 : Version 1 (DG);
 * 24-Mar-2004 : Added 'paint' argument to createTextBlock() method (DG);
 * 07-Apr-2004 : Added getTextBounds() method and useFontMetricsGetStringBounds
 *               flag (DG);
 * 08-Apr-2004 : Changed word break iterator to line break iterator in the 
 *               createTextBlock() method - see bug report 926074 (DG);
 * 03-Sep-2004 : Updated createTextBlock() method to add ellipses when limit 
 *               is reached (DG);
 * 30-Sep-2004 : Modified bounds returned by drawAlignedString() method (DG);
 * 10-Nov-2004 : Added new createTextBlock() method that works with 
 *               newlines (DG);
 * 19-Apr-2005 : Changed default value of useFontMetricsGetStringBounds (DG);
 * 17-May-2005 : createTextBlock() now recognises '\n' (DG);
 * 27-Jun-2005 : Added code to getTextBounds() method to work around Sun's bug 
 *               parade item 6183356 (DG);
 * 06-Jan-2006 : Reformatted (DG);
 * 
 */

package org.jfree.text;

import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.font.TextLayout;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.text.BreakIterator;

import org.jfree.ui.TextAnchor;
import org.jfree.util.Log;
import org.jfree.util.LogContext;
import org.jfree.base.BaseBoot;

/**
 * Some utility methods for working with text.
 *
 * @author David Gilbert
 */
public class TextUtilities {

    /** Access to logging facilities. */
    protected static final LogContext logger = Log.createContext(
            TextUtilities.class);

    /**
     * A flag that controls whether or not the rotated string workaround is
     * used.
     */
    private static boolean useDrawRotatedStringWorkaround;

    /**
     * A flag that controls whether the FontMetrics.getStringBounds() method
     * is used or a workaround is applied.
     */
    private static boolean useFontMetricsGetStringBounds;

    static {
        boolean isJava14;
        try {
            Class.forName("java.nio.Buffer");
            isJava14 = true;
        }
        catch (ClassNotFoundException e) {
            isJava14 = false;
        }

        final String configRotatedStringWorkaround =
              BaseBoot.getInstance().getGlobalConfig().getConfigProperty(
                      "org.jfree.text.UseDrawRotatedStringWorkaround", "auto");
        if (configRotatedStringWorkaround.equals("auto")) {
           useDrawRotatedStringWorkaround = isJava14 == false;
        } 
        else {
            useDrawRotatedStringWorkaround 
                    = configRotatedStringWorkaround.equals("true");
        }

        final String configFontMetricsStringBounds 
                = BaseBoot.getInstance().getGlobalConfig().getConfigProperty(
                        "org.jfree.text.UseFontMetricsGetStringBounds", "auto");
        if (configFontMetricsStringBounds.equals("auto")) {
            useFontMetricsGetStringBounds = isJava14 == true;
        }
        else {
            useFontMetricsGetStringBounds 
                    = configFontMetricsStringBounds.equals("true");
        }
    }

    /**
     * Private constructor prevents object creation.
     */
    private TextUtilities() {
    }

    /**
     * Creates a {@link TextBlock} from a <code>String</code>.  Line breaks 
     * are added where the <code>String</code> contains '\n' characters.
     * 
     * @param text  the text.
     * @param font  the font.
     * @param paint  the paint.
     * 
     * @return A text block.
     */
    public static TextBlock createTextBlock(final String text, final Font font,
                                            final Paint paint) {
        if (text == null) {
            throw new IllegalArgumentException("Null 'text' argument.");
        }
        final TextBlock result = new TextBlock();
        String input = text;
        boolean moreInputToProcess = (text.length() > 0);
        final int start = 0;
        while (moreInputToProcess) {
            final int index = input.indexOf("\n");
            if (index > start) {
                final String line = input.substring(start, index);
                if (index < input.length() - 1) {
                    result.addLine(line, font, paint);
                    input = input.substring(index + 1);
                }
                else {
                    moreInputToProcess = false;
                }
            }
            else if (index == start) {
                if (index < input.length() - 1) {
                    input = input.substring(index + 1);
                }
                else {
                    moreInputToProcess = false;
                }
            }
            else {
                result.addLine(input, font, paint);
                moreInputToProcess = false;
            }
        }
        return result;
    }

    /**
     * Creates a new text block from the given string, breaking the
     * text into lines so that the <code>maxWidth</code> value is
     * respected.
     * 
     * @param text  the text.
     * @param font  the font.
     * @param paint  the paint.
     * @param maxWidth  the maximum width for each line.
     * @param measurer  the text measurer.
     * 
     * @return A text block.
     */
    public static TextBlock createTextBlock(final String text, final Font font,
            final Paint paint, final float maxWidth, 
            final TextMeasurer measurer) {
        
        return createTextBlock(text, font, paint, maxWidth, Integer.MAX_VALUE, 
                measurer);
    }

    /**
     * Creates a new text block from the given string, breaking the
     * text into lines so that the <code>maxWidth</code> value is
     * respected.
     * 
     * @param text  the text.
     * @param font  the font.
     * @param paint  the paint.
     * @param maxWidth  the maximum width for each line.
     * @param maxLines  the maximum number of lines.
     * @param measurer  the text measurer.
     * 
     * @return A text block.
     */
    public static TextBlock createTextBlock(final String text, final Font font,
            final Paint paint, final float maxWidth, final int maxLines,
            final TextMeasurer measurer) {
        
        final TextBlock result = new TextBlock();
        final BreakIterator iterator = BreakIterator.getLineInstance();
        iterator.setText(text);
        int current = 0;
        int lines = 0;
        final int length = text.length();
        while (current < length && lines < maxLines) {
            final int next = nextLineBreak(text, current, maxWidth, iterator, 
                    measurer);
            if (next == BreakIterator.DONE) {
                result.addLine(text.substring(current), font, paint);
                return result;
            }
            result.addLine(text.substring(current, next), font, paint);
            lines++;
            current = next;
            while (current < text.length()&& text.charAt(current) == '\n') {
                current++;
            }
        }
        if (current < length) {
            final TextLine lastLine = result.getLastLine();
            final TextFragment lastFragment = lastLine.getLastTextFragment();
            final String oldStr = lastFragment.getText();
            String newStr = "...";
            if (oldStr.length() > 3) {
                newStr = oldStr.substring(0, oldStr.length() - 3) + "...";
            }

            lastLine.removeFragment(lastFragment);
            final TextFragment newFragment = new TextFragment(newStr, 
                    lastFragment.getFont(), lastFragment.getPaint());
            lastLine.addFragment(newFragment);
        }
        return result;
    }

    /**
     * Returns the character index of the next line break.
     * 
     * @param text  the text.
     * @param start  the start index.
     * @param width  the target display width.
     * @param iterator  the word break iterator.
     * @param measurer  the text measurer.
     * 
     * @return The index of the next line break.
     */
    private static int nextLineBreak(final String text, final int start,
            final float width, final BreakIterator iterator,
            final TextMeasurer measurer) {
        
        // this method is (loosely) based on code in JFreeReport's 
        // TextParagraph class
        int current = start;
        int end;
        float x = 0.0f;
        boolean firstWord = true;
        int newline = text.indexOf('\n', start);
        if (newline < 0) {
            newline = Integer.MAX_VALUE;
        }
        while (((end = iterator.next()) != BreakIterator.DONE)) {
            if (end > newline) {
                return newline;
            }
            x += measurer.getStringWidth(text, current, end);
            if (x > width) {
                if (firstWord) {
                    while (measurer.getStringWidth(text, start, end) > width) {
                        end--;
                        if (end <= start) {