Utils.java Source code

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Here is the source code for Utils.java

Source

/*
 *
 * Created on March 16, 2007, 4:34 PM
 *
 * Copyright 2006-2007 Nigel Hughes
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at http://www.apache.org/
 * licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.RenderingHints;
import java.awt.Transparency;
import java.awt.font.FontRenderContext;
import java.awt.font.LineBreakMeasurer;
import java.awt.font.TextAttribute;
import java.awt.font.TextLayout;
import java.awt.image.BufferedImage;
import java.text.AttributedCharacterIterator;
import java.text.AttributedString;
import java.util.Hashtable;
import java.util.LinkedList;

/**
    
 * @author nigel
 */
public class Utils {
    /** 
     * Renders multiple paragraphs of text in an array to an image (created and returned). 
     *
     * @param font The font to use
     * @param textColor The color of the text
     * @param text The message in an array of strings (one paragraph in each
     * @param width The width the text should be limited to
     * @return An image with the text rendered into it
     */
    public static BufferedImage renderTextToImage(Font font, Color textColor, String text[], int width) {
        LinkedList<BufferedImage> images = new LinkedList<BufferedImage>();

        int totalHeight = 0;

        for (String paragraph : text) {
            BufferedImage paraImage = renderTextToImage(font, textColor, paragraph, width);
            totalHeight += paraImage.getHeight();
            images.add(paraImage);
        }

        BufferedImage image = createCompatibleImage(width, totalHeight);
        Graphics2D graphics = (Graphics2D) image.createGraphics();

        int y = 0;

        for (BufferedImage paraImage : images) {
            graphics.drawImage(paraImage, 0, y, null);
            y += paraImage.getHeight();
        }

        graphics.dispose();
        return image;
    }

    /** 
     * Renders a paragraph of text (line breaks ignored) to an image (created and returned). 
     *
     * @param font The font to use
     * @param textColor The color of the text
     * @param text The message
     * @param width The width the text should be limited to
     * @return An image with the text rendered into it
     */
    public static BufferedImage renderTextToImage(Font font, Color textColor, String text, int width) {
        Hashtable map = new Hashtable();
        map.put(TextAttribute.FONT, font);
        AttributedString attributedString = new AttributedString(text, map);
        AttributedCharacterIterator paragraph = attributedString.getIterator();

        FontRenderContext frc = new FontRenderContext(null, false, false);
        int paragraphStart = paragraph.getBeginIndex();
        int paragraphEnd = paragraph.getEndIndex();
        LineBreakMeasurer lineMeasurer = new LineBreakMeasurer(paragraph, frc);

        float drawPosY = 0;

        //First time around, just determine the height
        while (lineMeasurer.getPosition() < paragraphEnd) {
            TextLayout layout = lineMeasurer.nextLayout(width);

            // Move it down
            drawPosY += layout.getAscent() + layout.getDescent() + layout.getLeading();
        }

        BufferedImage image = createCompatibleImage(width, (int) drawPosY);
        Graphics2D graphics = (Graphics2D) image.getGraphics();
        graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);

        drawPosY = 0;
        lineMeasurer.setPosition(paragraphStart);
        while (lineMeasurer.getPosition() < paragraphEnd) {
            TextLayout layout = lineMeasurer.nextLayout(width);

            // Move y-coordinate by the ascent of the layout.
            drawPosY += layout.getAscent();

            /* Compute pen x position.  If the paragraph is
               right-to-left, we want to align the TextLayouts
               to the right edge of the panel.
             */
            float drawPosX;
            if (layout.isLeftToRight()) {
                drawPosX = 0;
            } else {
                drawPosX = width - layout.getAdvance();
            }

            // Draw the TextLayout at (drawPosX, drawPosY).
            layout.draw(graphics, drawPosX, drawPosY);

            // Move y-coordinate in preparation for next layout.
            drawPosY += layout.getDescent() + layout.getLeading();
        }

        graphics.dispose();
        return image;
    }

    /**
     * Creates an image compatible with the current display
     * 
     * @return A BufferedImage with the appropriate color model
     */
    public static BufferedImage createCompatibleImage(int width, int height) {
        GraphicsConfiguration configuration = GraphicsEnvironment.getLocalGraphicsEnvironment()
                .getDefaultScreenDevice().getDefaultConfiguration();
        return configuration.createCompatibleImage(width, height, Transparency.TRANSLUCENT);
    }
}