1 ////////////////////////////////////////////////////////////////////////////////
2 // MillScript: an Open Spice interpreter and batch website creation tool
3 // Copyright (C) 2004-2005 Kevin Rogers
4 //
5 // This file is part of MillScript.
6 //
7 // MillScript is free software; you can redistribute it and/or modify it under
8 // the terms of the GNU General Public License as published by the Free
9 // Software Foundation; either version 2 of the License, or (at your option)
10 // any later version.
11 //
12 // MillScript is distributed in the hope that it will be useful, but WITHOUT
13 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 // more details.
16 //
17 // You should have received a copy of the GNU General Public License along with
18 // MillScript; if not, write to the Free Software Foundation, Inc., 59 Temple
19 // Place, Suite 330, Boston, MA 02111-1307 USA
20 ////////////////////////////////////////////////////////////////////////////////
21 package org.millscript.millscript.loaders;
22
23 import org.millscript.commons.vfs.VFile;
24 import org.millscript.millscript.alert.Alerts;
25 import org.millscript.millscript.datatypes.DeferredSoftReference;
26 import org.millscript.millscript.datatypes.RasterImage;
27
28 import java.io.IOException;
29
30 import javax.imageio.ImageIO;
31
32 /**
33 * General purporse raster image file loader. The exact type of file we are
34 * loading is determined from the file extension. We could force the issue by
35 * hard coding a specific image reader.
36 */
37 public final class RasterImageLoader extends ValueLoader {
38
39 /**
40 * @see org.millscript.millscript.loaders.Loader#loadValue()
41 */
42 @Override
43 public Object loadValue() {
44 if ( this.entry instanceof VFile && this.entry.exists() ) {
45 // Return a new deferred soft reference to load the image as required.
46 return new DeferredSoftReference< RasterImage >() {
47 /* (non-Javadoc)
48 * @see org.millscript.millscript.datatypes.Deferred#calculate()
49 */
50 @Override
51 public RasterImage calculate() {
52 try {
53 return new RasterImage( ImageIO.read( ((VFile) entry).getInputStream() ) );
54 } catch ( IOException ex ) {
55 throw Alerts.eval(
56 "Cannot load image",
57 null
58 ).culprit( "file", entry ).culprit( "message", ex.getMessage() ).mishap();
59 }
60 }
61 };
62 } else {
63 throw(
64 Alerts.compile(
65 "Inventory entry is not a file",
66 "Raster image loader can only be used to load files"
67 ).culprit( "entry", this.entry ).mishap()
68 );
69 }
70 }
71
72 }