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.webrender;
31:
32: import java.io.Serializable;
33: import java.util.HashSet;
34: import java.util.Set;
35:
36: /**
37: * Provides information about changes to <code>UserInstance</code> properties
38: * of which the client engine needs to be informed.
39: */
40: public class UserInstanceUpdateManager implements Serializable {
41:
42: private static final String[] EMPTY_STRING_ARRAY = new String[0];
43: private Set updatedPropertyNames = new HashSet();
44:
45: /**
46: * Retrieves the names of updated properties.
47: * This method is queried by the <code>SynchronizeService</code>.
48: *
49: * @return an array of the updated property names (returns an empty array
50: * if no properties have changed)
51: */
52: public String[] getPropertyUpdateNames() {
53: int size = updatedPropertyNames.size();
54: if (size == 0) {
55: return EMPTY_STRING_ARRAY;
56: }
57: return (String[]) updatedPropertyNames
58: .toArray(new String[size]);
59: }
60:
61: /**
62: * Processes a property update from the <code>UserInstance</code>, storing
63: * the name of the property in the list of properties to be updated.
64: *
65: * @param name the name of the property
66: */
67: void processPropertyUpdate(String name) {
68: updatedPropertyNames.add(name);
69: }
70:
71: /**
72: * Purges list of updated property names.
73: * This method is invoked by the <code>SynchronizeService</code> when it
74: * has finished rendering the updates to the client.
75: */
76: public void purge() {
77: updatedPropertyNames.clear();
78: }
79: }
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