KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > eclipse > jface > internal > databinding > internal > swt > CComboObservableValue


1 /*******************************************************************************
2  * Copyright (c) 2005, 2007 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 164653
11  * Ashley Cambrell - bug 198904
12  *******************************************************************************/
13 package org.eclipse.jface.internal.databinding.internal.swt;
14
15 import org.eclipse.core.databinding.observable.Diffs;
16 import org.eclipse.jface.internal.databinding.provisional.swt.AbstractSWTObservableValue;
17 import org.eclipse.jface.util.Assert;
18 import org.eclipse.swt.custom.CCombo;
19 import org.eclipse.swt.events.ModifyEvent;
20 import org.eclipse.swt.events.ModifyListener;
21
22 /**
23  * @since 3.2
24  *
25  */
26 public class CComboObservableValue extends AbstractSWTObservableValue {
27
28     /**
29      *
30      */
31
32     private final CCombo ccombo;
33
34     private final String JavaDoc attribute;
35
36     private boolean updating = false;
37
38     private String JavaDoc currentValue;
39
40     private ModifyListener modifyListener;
41
42     /**
43      * @param ccombo
44      * @param attribute
45      */
46     public CComboObservableValue(CCombo ccombo, String JavaDoc attribute) {
47         super(ccombo);
48         this.ccombo = ccombo;
49         this.attribute = attribute;
50
51         if (attribute.equals(SWTProperties.SELECTION)
52                 || attribute.equals(SWTProperties.TEXT)) {
53             this.currentValue = ccombo.getText();
54             modifyListener = new ModifyListener() {
55
56                 public void modifyText(ModifyEvent e) {
57                     if (!updating) {
58                         String JavaDoc oldValue = currentValue;
59                         currentValue = CComboObservableValue.this.ccombo
60                                 .getText();
61                         fireValueChange(Diffs.createValueDiff(oldValue,
62                                 currentValue));
63                     }
64                 }
65             };
66             ccombo.addModifyListener(modifyListener);
67         } else
68             throw new IllegalArgumentException JavaDoc();
69     }
70
71     public void doSetValue(final Object JavaDoc value) {
72         String JavaDoc oldValue = ccombo.getText();
73         try {
74             updating = true;
75             if (attribute.equals(SWTProperties.TEXT)) {
76                 String JavaDoc stringValue = value != null ? value.toString() : ""; //$NON-NLS-1$
77 ccombo.setText(stringValue);
78             } else if (attribute.equals(SWTProperties.SELECTION)) {
79                 String JavaDoc items[] = ccombo.getItems();
80                 int index = -1;
81                 if (items != null && value != null) {
82                     for (int i = 0; i < items.length; i++) {
83                         if (value.equals(items[i])) {
84                             index = i;
85                             break;
86                         }
87                     }
88                     if (index == -1) {
89                         ccombo.setText((String JavaDoc) value);
90                     } else {
91                         ccombo.select(index); // -1 will not "unselect"
92 }
93                 }
94             }
95         } finally {
96             updating = false;
97         }
98         fireValueChange(Diffs.createValueDiff(oldValue, ccombo.getText()));
99     }
100
101     public Object JavaDoc doGetValue() {
102         if (attribute.equals(SWTProperties.TEXT))
103             return ccombo.getText();
104
105         Assert.isTrue(attribute.equals(SWTProperties.SELECTION),
106                 "unexpected attribute: " + attribute); //$NON-NLS-1$
107 // The problem with a ccombo, is that it changes the text and
108 // fires before it update its selection index
109 return ccombo.getText();
110     }
111
112     public Object JavaDoc getValueType() {
113         Assert.isTrue(attribute.equals(SWTProperties.TEXT)
114                 || attribute.equals(SWTProperties.SELECTION),
115                 "unexpected attribute: " + attribute); //$NON-NLS-1$
116 return String JavaDoc.class;
117     }
118
119     /**
120      * @return attribute being observed
121      */
122     public String JavaDoc getAttribute() {
123         return attribute;
124     }
125
126     /*
127      * (non-Javadoc)
128      *
129      * @see org.eclipse.core.databinding.observable.value.AbstractObservableValue#dispose()
130      */
131     public synchronized void dispose() {
132         super.dispose();
133
134         if (modifyListener != null && !ccombo.isDisposed()) {
135             ccombo.removeModifyListener(modifyListener);
136         }
137     }
138 }
139
Popular Tags