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Java > Open Source Codes > com > nwalsh > xalan > ImageIntrinsics


1 package com.nwalsh.xalan;
2
3 import java.io.*;
4 import java.awt.*;
5 import java.awt.image.*;
6 import java.lang.Thread JavaDoc;
7 import java.util.StringTokenizer JavaDoc;
8
9 import org.apache.xalan.extensions.ExpressionContext;
10
11 /**
12  * <p>Saxon extension to examine intrinsic size of images</p>
13  *
14  * <p>$Id: ImageIntrinsics.java,v 1.2 2004/09/05 11:32:31 xmldoc Exp $</p>
15  *
16  * <p>Copyright (C) 2002 Norman Walsh.</p>
17  *
18  * <p>This class provides a
19  * <a HREF="http://xml.apache.org/">Xalan</a>
20  * extension to find the intrinsic size of images.</p>
21  *
22  * <p><b>Change Log:</b></p>
23  * <dl>
24  * <dt>1.0</dt>
25  * <dd><p>Initial release.</p></dd>
26  * </dl>
27  *
28  * @author Norman Walsh
29  * <a HREF="mailto:ndw@nwalsh.com">ndw@nwalsh.com</a>
30  *
31  * @version $Id: ImageIntrinsics.java,v 1.2 2004/09/05 11:32:31 xmldoc Exp $
32  *
33  */
34 public class ImageIntrinsics implements ImageObserver {
35   boolean imageLoaded = false;
36   boolean imageFailed = false;
37   Image image = null;
38   int width = -1;
39   int depth = -1;
40
41   /**
42    * <p>Constructor for ImageIntrinsics</p>
43    */
44   public ImageIntrinsics(ExpressionContext context, String JavaDoc imageFn) {
45     System.setProperty("java.awt.headless","true");
46     image = Toolkit.getDefaultToolkit().getImage (imageFn);
47     width = image.getWidth(this);
48
49     while (!imageFailed && (width == -1 || depth == -1)) {
50       try {
51     java.lang.Thread.currentThread().sleep(50);
52       } catch (Exception JavaDoc e) {
53     // nop;
54 }
55       width = image.getWidth(this);
56       depth = image.getHeight(this);
57     }
58
59     if (imageFailed) {
60       // Maybe it's an EPS or PDF?
61 // FIXME: this code is crude
62 BufferedReader ir = null;
63       String JavaDoc line = null;
64       int lineLimit = 100;
65
66       try {
67     ir = new BufferedReader(new FileReader(new File(imageFn)));
68     line = ir.readLine();
69
70     if (line != null && line.startsWith("%PDF-")) {
71       // We've got a PDF!
72 while (lineLimit > 0 && line != null) {
73         lineLimit--;
74         if (line.startsWith("/CropBox [")) {
75           line = line.substring(10);
76           if (line.indexOf("]") >= 0) {
77         line = line.substring(0, line.indexOf("]"));
78           }
79           parseBox(line);
80           lineLimit = 0;
81         }
82         line = ir.readLine();
83       }
84     } else if (line != null && line.startsWith("%!") && line.indexOf(" EPSF-") > 0) {
85       // We've got an EPS!
86 while (lineLimit > 0 && line != null) {
87         lineLimit--;
88         if (line.startsWith("%%BoundingBox: ")) {
89           line = line.substring(15);
90           parseBox(line);
91           lineLimit = 0;
92         }
93         line = ir.readLine();
94       }
95     }
96       } catch (Exception JavaDoc e) {
97     // nop;
98 }
99
100       if (ir != null) {
101     try {
102       ir.close();
103     } catch (Exception JavaDoc e) {
104       // nop;
105 }
106       }
107     }
108   }
109
110   public int getWidth(ExpressionContext context, int defaultWidth) {
111     if (width >= 0) {
112       return width;
113     } else {
114       return defaultWidth;
115     }
116   }
117
118   public int getDepth(ExpressionContext context, int defaultDepth) {
119     if (depth >= 0) {
120       return depth;
121     } else {
122       return defaultDepth;
123     }
124   }
125
126   private void parseBox(String JavaDoc line) {
127     int [] corners = new int [4];
128     int count = 0;
129
130     StringTokenizer JavaDoc st = new StringTokenizer JavaDoc(line);
131     while (count < 4 && st.hasMoreTokens()) {
132       try {
133     corners[count++] = Integer.parseInt(st.nextToken());
134       } catch (Exception JavaDoc e) {
135     // nop;
136 }
137     }
138
139     width = corners[2] - corners[0];
140     depth = corners[3] - corners[1];
141   }
142
143   public boolean imageUpdate(Image img, int infoflags,
144                  int x, int y, int width, int height) {
145     if ((infoflags & ImageObserver.ERROR) == ImageObserver.ERROR) {
146       imageFailed = true;
147       return false;
148     }
149
150     // I really only care about the width and height, but if I return false as
151 // soon as those are available, the BufferedInputStream behind the loader
152 // gets closed too early.
153 int flags = ImageObserver.ALLBITS;
154     if ((infoflags & flags) == flags) {
155       return false;
156     } else {
157       return true;
158     }
159   }
160 }
161
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