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comparison org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/swt/TextObservableValue.d @ 78:0a55d2d5a946

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Added file for databinding
author Frank Benoit <benoit@tionex.de>
date Tue, 14 Apr 2009 11:35:29 +0200
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76:f05e6e8b2f2d 78:0a55d2d5a946
1 /*******************************************************************************
2 * Copyright (c) 2005, 2008 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 * Brad Reynolds (bug 135446)
11 * Brad Reynolds - bug 164653
12 *******************************************************************************/
13 module org.eclipse.jface.internal.databinding.swt.TextObservableValue;
14
15 import java.lang.all;
16
17 import org.eclipse.core.databinding.observable.Diffs;
18 import org.eclipse.core.databinding.observable.IObservable;
19 import org.eclipse.core.databinding.observable.Realm;
20 import org.eclipse.jface.databinding.swt.SWTObservables;
21 import org.eclipse.jface.internal.databinding.provisional.swt.AbstractSWTVetoableValue;
22 import org.eclipse.swt.SWT;
23 import org.eclipse.swt.events.VerifyEvent;
24 import org.eclipse.swt.events.VerifyListener;
25 import org.eclipse.swt.widgets.Event;
26 import org.eclipse.swt.widgets.Listener;
27 import org.eclipse.swt.widgets.Text;
28
29 /**
30 * {@link IObservable} implementation that wraps a {@link Text} widget. The time
31 * at which listeners should be notified about changes to the text is specified
32 * on construction.
33 *
34 * <dl>
35 * <dt>Events:</dt>
36 * <dd> If the update event type (specified on construction) is
37 * <code>SWT.Modify</code> a value change event will be fired on every key
38 * stroke. If the update event type is <code>SWT.FocusOut</code> a value
39 * change event will be fired on focus out. When in either mode if the user is
40 * entering text and presses [Escape] the value will be reverted back to the
41 * last value set using doSetValue(). Regardless of the update event type a
42 * value changing event will fire on verify to enable vetoing of changes.</dd>
43 * </dl>
44 *
45 * @since 1.0
46 */
47 public class TextObservableValue : AbstractSWTVetoableValue {
48
49 /**
50 * {@link Text} widget that this is being observed.
51 */
52 private final Text text;
53
54 /**
55 * Flag to track when the model is updating the widget. When
56 * <code>true</code> the handlers for the SWT events should not process
57 * the event as this would cause an infinite loop.
58 */
59 private bool updating = false;
60
61 /**
62 * SWT event that on firing this observable will fire change events to its
63 * listeners.
64 */
65 private final int updateEventType;
66
67 /**
68 * Valid types for the {@link #updateEventType}.
69 */
70 private static const int[] validUpdateEventTypes = [ SWT.Modify,
71 SWT.FocusOut, SWT.None ];
72
73 /**
74 * Previous value of the Text.
75 */
76 private String oldValue;
77
78 private Listener updateListener = new class() Listener {
79 public void handleEvent(Event event) {
80 if (!updating) {
81 String newValue = text.getText();
82
83 if (!newValue.equals(oldValue)) {
84 fireValueChange(Diffs.createValueDiff(oldValue, newValue));
85 oldValue = newValue;
86 }
87 }
88 }
89 };
90
91 private VerifyListener verifyListener;
92
93 /**
94 * Constructs a new instance bound to the given <code>text</code> widget
95 * and configured to fire change events to its listeners at the time of the
96 * <code>updateEventType</code>.
97 *
98 * @param text
99 * @param updateEventType
100 * SWT event constant as to what SWT event to update the model in
101 * response to. Appropriate values are: <code>SWT.Modify</code>,
102 * <code>SWT.FocusOut</code>, <code>SWT.None</code>.
103 * @throws IllegalArgumentException
104 * if <code>updateEventType</code> is an incorrect type.
105 */
106 public this(Text text, int updateEventType) {
107 this(SWTObservables.getRealm(text.getDisplay()), text, updateEventType);
108 }
109
110 /**
111 * Constructs a new instance.
112 *
113 * @param realm can not be <code>null</code>
114 * @param text
115 * @param updateEventType
116 */
117 public this(Realm realm, Text text, int updateEventType) {
118 super(realm, text);
119
120 bool eventValid = false;
121 for (int i = 0; !eventValid && i < validUpdateEventTypes.length; i++) {
122 eventValid = (updateEventType is validUpdateEventTypes[i]);
123 }
124 if (!eventValid) {
125 throw new IllegalArgumentException(
126 "UpdateEventType [" + updateEventType + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
127 }
128 this.text = text;
129 this.updateEventType = updateEventType;
130 if (updateEventType !is SWT.None) {
131 text.addListener(updateEventType, updateListener);
132 }
133
134 oldValue = text.getText();
135
136 verifyListener = new class() VerifyListener {
137 public void verifyText(VerifyEvent e) {
138 if (!updating) {
139 String currentText = text
140 .getText();
141 String newText = currentText.substring(0, e.start) + e.text
142 + currentText.substring(e.end);
143 if (!fireValueChanging(Diffs.createValueDiff(currentText,
144 newText))) {
145 e.doit = false;
146 }
147 }
148 }
149 };
150 text.addVerifyListener(verifyListener);
151 }
152
153 /**
154 * Sets the bound {@link Text Text's} text to the passed <code>value</code>.
155 *
156 * @param value
157 * new value, String expected
158 * @see org.eclipse.core.databinding.observable.value.AbstractVetoableValue#doSetApprovedValue(java.lang.Object)
159 * @throws ClassCastException
160 * if the value is anything other than a String
161 */
162 protected void doSetApprovedValue(Object value) {
163 try {
164 updating = true;
165 text.setText(value is null ? "" : value.toString()); //$NON-NLS-1$
166 oldValue = text.getText();
167 } finally {
168 updating = false;
169 }
170 }
171
172 /**
173 * Returns the current value of the {@link Text}.
174 *
175 * @see org.eclipse.core.databinding.observable.value.AbstractVetoableValue#doGetValue()
176 */
177 public Object doGetValue() {
178 return oldValue = text.getText();
179 }
180
181 /**
182 * Returns the type of the value from {@link #doGetValue()}, i.e.
183 * String.class
184 *
185 * @see org.eclipse.core.databinding.observable.value.IObservableValue#getValueType()
186 */
187 public Object getValueType() {
188 return String.classinfo;
189 }
190
191 public void dispose() {
192 if (!text.isDisposed()) {
193 if (updateEventType !is SWT.None) {
194 text.removeListener(updateEventType, updateListener);
195 }
196 text.removeVerifyListener(verifyListener);
197 }
198 super.dispose();
199 }
200 }