01: /*
02: * This file is part of the Echo Web Application Framework (hereinafter "Echo").
03: * Copyright (C) 2002-2005 NextApp, Inc.
04: *
05: * Version: MPL 1.1/GPL 2.0/LGPL 2.1
06: *
07: * The contents of this file are subject to the Mozilla Public License Version
08: * 1.1 (the "License"); you may not use this file except in compliance with
09: * the License. You may obtain a copy of the License at
10: * http://www.mozilla.org/MPL/
11: *
12: * Software distributed under the License is distributed on an "AS IS" basis,
13: * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14: * for the specific language governing rights and limitations under the
15: * License.
16: *
17: * Alternatively, the contents of this file may be used under the terms of
18: * either the GNU General Public License Version 2 or later (the "GPL"), or
19: * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
20: * in which case the provisions of the GPL or the LGPL are applicable instead
21: * of those above. If you wish to allow use of your version of this file only
22: * under the terms of either the GPL or the LGPL, and not to allow others to
23: * use your version of this file under the terms of the MPL, indicate your
24: * decision by deleting the provisions above and replace them with the notice
25: * and other provisions required by the GPL or the LGPL. If you do not delete
26: * the provisions above, a recipient may use your version of this file under
27: * the terms of any one of the MPL, the GPL or the LGPL.
28: */
29:
30: package nextapp.echo2.webcontainer.image;
31:
32: import nextapp.echo2.app.Component;
33: import nextapp.echo2.app.ImageReference;
34:
35: /**
36: * An optional interface which may be implemented by
37: * <code>ComponentSynchronizePeer</code>s to render images via the
38: * <code>ImageRenderService</code>.
39: */
40: public interface ImageRenderSupport {
41:
42: /**
43: * Retrieves the image identified by the given <code>imageId</code> value
44: * for the given <code>Component</code>.
45: * <p>
46: * <strong>Note:</strong> A reference to any images to be rendered must be
47: * maintained throughout the rendering process, due to the fact that the
48: * image rendering subsystem creates a weak-keyed cache of images to be
49: * rendered. This method therefore may not simply return a new,
50: * otherwise-unreferenced image. In the event that this presents a problem,
51: * the recommended workaround is to simply store such otherwise unreferenced
52: * <code>ImageReference</code>s using a <code>RenderState</code> object.
53: *
54: * @param component the component
55: * @param imageId the id of the image
56: * @return the target image
57: */
58: public ImageReference getImage(Component component, String imageId);
59: }
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