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.servermessage;
31:
32: import nextapp.echo2.webrender.ServerMessage;
33:
34: import org.w3c.dom.Element;
35:
36: /**
37: * A utility class to add <code>EchoEventProcessor</code> message parts to the
38: * <code>ServerMessage</code>. <code>EchoEventProcessor</code> message parts
39: * are used to register/unregister client-side event listeners.
40: */
41: public class EventProcessor {
42:
43: private static final String MESSAGE_PART_NAME = "EchoEventProcessor.MessageProcessor";
44: private static final String[] EVENT_ADD_KEYS = new String[] {
45: "type", "handler" };
46: private static final String[] EVENT_REMOVE_KEYS = new String[] { "type" };
47:
48: /**
49: * Creates an <code>event-add</code> operation to register a client event
50: * listener of a particular type on an HTML element.
51: *
52: * @param serverMessage the outgoing <code>ServerMessage</code>
53: * @param eventType the type of event (the "on" prefix should be
54: * omitted, e.g., "onmousedown" would be expressed as
55: * "mousedown")
56: * @param elementId the id of the listened-to DOM element
57: * @param eventHandler the name of the handler method to be invoked
58: * when the event occurs, e.g., "EchoButton.processAction"
59: */
60: public static void renderEventAdd(ServerMessage serverMessage,
61: String eventType, String elementId, String eventHandler) {
62: Element itemizedUpdateElement = serverMessage
63: .getItemizedDirective(
64: ServerMessage.GROUP_ID_POSTUPDATE,
65: MESSAGE_PART_NAME, "event-add", EVENT_ADD_KEYS,
66: new String[] { eventType, eventHandler });
67: Element itemElement = serverMessage.getDocument()
68: .createElement("item");
69: itemElement.setAttribute("eid", elementId);
70: itemizedUpdateElement.appendChild(itemElement);
71: }
72:
73: /**
74: * Creates an <code>event-remove</code> operation to unregister a client
75: * event listener of a particular type on an HTML element.
76: *
77: * @param serverMessage the outgoing <code>ServerMessage</code>
78: * @param eventType the type of event (the "on" prefix should be
79: * omitted, e.g., "onmousedown" would be expressed as
80: * "mousedown")
81: * @param elementId the id of the listened-to DOM element
82: */
83: public static void renderEventRemove(ServerMessage serverMessage,
84: String eventType, String elementId) {
85: Element itemizedUpdateElement = serverMessage
86: .getItemizedDirective(ServerMessage.GROUP_ID_PREREMOVE,
87: MESSAGE_PART_NAME, "event-remove",
88: EVENT_REMOVE_KEYS, new String[] { eventType });
89: Element itemElement = serverMessage.getDocument()
90: .createElement("item");
91: itemElement.setAttribute("eid", elementId);
92: itemizedUpdateElement.appendChild(itemElement);
93: }
94: }
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