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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.assetstudiolib;
     18 
     19 import java.awt.Color;
     20 import java.awt.Font;
     21 import java.awt.Graphics2D;
     22 import java.awt.RenderingHints;
     23 import java.awt.font.FontRenderContext;
     24 import java.awt.font.TextLayout;
     25 import java.awt.geom.Rectangle2D;
     26 import java.awt.image.BufferedImage;
     27 
     28 /**
     29  * A set of utility classes for rendering text to a {@link BufferedImage}, suitable for use as a
     30  * source image to {@link GraphicGenerator} objects.
     31  */
     32 public class TextRenderUtil {
     33     /**
     34      * Renders the given string with the provided {@link Options} to a
     35      * {@link BufferedImage}.
     36      *
     37      * @param text The text to render.
     38      * @param paddingPercentage If nonzero, a percentage of the width or height
     39      *            (whichever is smaller) to add as padding around the text
     40      * @param options The optional parameters for rendering the text.
     41      * @return An image, suitable for use as an input to a
     42      *         {@link GraphicGenerator}.
     43      */
     44     public static BufferedImage renderTextImage(String text, int paddingPercentage,
     45             Options options) {
     46         if (options == null) {
     47             options = new Options();
     48         }
     49 
     50         BufferedImage tempImage = Util.newArgbBufferedImage(1, 1);
     51         if (text == null || text.equals("")) {
     52             return tempImage;
     53         }
     54 
     55         Graphics2D tempG = (Graphics2D) tempImage.getGraphics();
     56 
     57         Font font = options.font;
     58         if (font == null) {
     59             font = new Font(options.fontName, options.fontStyle, options.fontSize);
     60             // Map<TextAttribute, Object> map = new Hashtable<TextAttribute, Object>();
     61             // map.put(TextAttribute.TRACKING, 0.3);
     62             // font = font.deriveFont(map);
     63         }
     64 
     65         FontRenderContext frc = tempG.getFontRenderContext();
     66 
     67         TextLayout layout = new TextLayout(text, font, frc);
     68         Rectangle2D bounds = layout.getBounds();
     69 
     70         // The padding is a percentage relative to the overall minimum of the width or height
     71         if (paddingPercentage != 0) {
     72             double minDimension = Math.min(bounds.getWidth(), bounds.getHeight());
     73             double delta = minDimension * paddingPercentage / 100;
     74             bounds.setRect(bounds.getMinX() - delta, bounds.getMinY() - delta,
     75                     bounds.getWidth() + 2 * delta, bounds.getHeight() + 2 * delta);
     76         }
     77 
     78         BufferedImage image = Util.newArgbBufferedImage(
     79                 Math.max(1, (int) bounds.getWidth()), Math.max(1, (int) bounds.getHeight()));
     80         Graphics2D g = (Graphics2D) image.getGraphics();
     81         g.setColor(new Color(options.foregroundColor, true));
     82         g.setFont(font);
     83 
     84         g.setRenderingHint(
     85                 RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
     86         g.setRenderingHint(
     87                 RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
     88 
     89         g.drawString(text, (float) -bounds.getX(), (float) -bounds.getY());
     90 
     91         g.dispose();
     92         tempG.dispose();
     93 
     94         return image;
     95     }
     96 
     97     /**
     98      * The parameters for text rendering. There are no required values so a <code>new
     99      * Options()</code> object is considered valid.
    100      */
    101     public static class Options {
    102         // We use a large default font size to reduce the need to scale generated images up.
    103         // TODO: Instead, a graphic generator should use a different source image for each density.
    104         private static final int DEFAULT_FONT_SIZE = 512;
    105 
    106         /** Foreground color to render text with, as an AARRGGBB packed integer */
    107         public int foregroundColor = 0xFFFFFFFF;
    108 
    109         /**
    110          * The optional {@link Font} to use. If null, a {@link Font} object will be generated using
    111          * the other options.
    112          */
    113         public Font font = null;
    114 
    115         /**
    116          * The optional font name. Defaults to {@link Font#SERIF}.
    117          *
    118          * @see Font#Font(String, int, int)
    119          */
    120         public String fontName = Font.SERIF;
    121 
    122         /**
    123          * The optional font styling (bold and/or italic). Defaults to no styling.
    124          *
    125          * @see Font#Font(String, int, int)
    126          */
    127         public int fontStyle = 0;
    128 
    129         /**
    130          * The optional font size, in points. Defaults to a very large font size, to prevent
    131          * up-scaling rendered text.
    132          *
    133          * @see Font#Font(String, int, int)
    134          */
    135         public int fontSize = DEFAULT_FONT_SIZE;
    136     }
    137 }
    138