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Java > Open Source Codes > org > apache > fop > image > ImageLoader


1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License. You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17
18 /* $Id: ImageLoader.java 426576 2006-07-28 15:44:37Z jeremias $ */
19  
20 package org.apache.fop.image;
21
22 import org.apache.fop.apps.FOUserAgent;
23
24 /**
25  * Class to load images.
26  */
27 class ImageLoader {
28     
29     private String JavaDoc url;
30     private ImageCache cache;
31     private boolean valid = true;
32     private FOUserAgent userAgent;
33     private FopImage image = null;
34
35     /**
36      * Main constructor.
37      * @param url URL to the image
38      * @param cache Image cache
39      * @param ua User agent
40      */
41     public ImageLoader(String JavaDoc url, ImageCache cache, FOUserAgent ua) {
42         this.url = url;
43         this.cache = cache;
44         this.userAgent = ua;
45     }
46
47     /**
48      * Loads the image.
49      * @return the loaded image
50      */
51     public synchronized FopImage loadImage() {
52         if (!valid || image != null) {
53             return image;
54         }
55         ImageFactory imageFactory = userAgent.getFactory().getImageFactory();
56         image = imageFactory.loadImage(url, userAgent);
57         if (image == null) {
58             cache.invalidateImage(url, userAgent);
59             valid = false;
60         }
61         return image;
62     }
63
64 }
65
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