1 // Permission is hereby granted, free of charge, to any person obtaining
2 // a copy of this software and associated documentation files (the
3 // "Software"), to deal in the Software without restriction, including
4 // without limitation the rights to use, copy, modify, merge, publish,
5 // distribute, sublicense, and/or sell copies of the Software, and to
6 // permit persons to whom the Software is furnished to do so, subject to
7 // the following conditions:
9 // The above copyright notice and this permission notice shall be
10 // included in all copies or substantial portions of the Software.
12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20 // Copyright (c) 2004-2005 Novell, Inc.
23 // Peter Bartok pbartok@novell.com
24 // Jackson Harper jackson@ximian.com
28 using System.ComponentModel;
30 namespace System.Windows.Forms {
32 [TypeConverter (typeof (ListBindingConverter))]
33 public class Binding {
35 private string property_name;
36 private object data_source;
37 private string data_member;
38 private BindingMemberInfo binding_member_info;
39 private Control control;
41 private BindingManagerBase manager;
42 private PropertyDescriptor prop_desc;
43 private PropertyDescriptor is_null_desc;
45 private EventDescriptor changed_event;
46 private EventHandler property_value_changed_handler;
47 private object event_current; // The manager.Current as far as the changed_event knows
50 private Type data_type;
52 #region Public Constructors
53 public Binding (string propertyName, object dataSource, string dataMember)
55 property_name = propertyName;
56 data_source = dataSource;
57 data_member = dataMember;
58 binding_member_info = new BindingMemberInfo (dataMember);
60 #endregion // Public Constructors
62 #region Public Instance Properties
63 public BindingManagerBase BindingManagerBase {
69 public BindingMemberInfo BindingMemberInfo {
71 return binding_member_info;
76 public Control Control {
82 public object DataSource {
89 public bool IsBinding {
96 public string PropertyName {
101 #endregion // Public Instance Properties
103 #region Protected Instance Methods
104 protected virtual void OnFormat (ConvertEventArgs cevent)
107 Format (this, cevent);
110 protected virtual void OnParse (ConvertEventArgs cevent)
113 Parse (this, cevent);
115 #endregion // Protected Instance Methods
118 internal void SetControl (Control control)
120 if (control == this.control)
123 prop_desc = TypeDescriptor.GetProperties (control).Find (property_name, false);
124 data_type = prop_desc.PropertyType; // Getting the PropertyType is kinda slow and it should never change, so it is cached
126 if (prop_desc == null)
127 throw new ArgumentException (String.Concat ("Cannot bind to property '", property_name, "' on target control."));
128 if (prop_desc.IsReadOnly)
129 throw new ArgumentException (String.Concat ("Cannot bind to property '", property_name, "' because it is read only."));
131 control.Validating += new CancelEventHandler (ControlValidatingHandler);
133 this.control = control;
136 internal void Check (BindingContext binding_context)
141 manager = control.BindingContext [data_source, property_name];
142 manager.AddBinding (this);
144 WirePropertyValueChangedEvent ();
146 is_null_desc = TypeDescriptor.GetProperties (manager.Current).Find (property_name + "IsNull", false);
151 internal void PushData ()
153 data = prop_desc.GetValue (control);
154 data = FormatData (data);
155 SetPropertyValue (data);
158 internal void PullData ()
160 if (is_null_desc != null) {
161 bool is_null = (bool) is_null_desc.GetValue (manager.Current);
163 data = Convert.DBNull;
168 if (data_member != null) {
169 PropertyDescriptor pd = TypeDescriptor.GetProperties (manager.Current).Find (data_member, true);
170 object pulled = pd.GetValue (manager.Current);
171 data = ParseData (pulled, pd.PropertyType);
173 object pulled = manager.Current;
174 data = ParseData (pulled, pulled.GetType ());
177 data = FormatData (data);
178 SetControlValue (data);
181 internal void UpdateIsBinding ()
186 private void SetControlValue (object data)
188 prop_desc.SetValue (control, data);
191 private void SetPropertyValue (object data)
193 PropertyDescriptor pd = TypeDescriptor.GetProperties (manager.Current).Find (data_member, true);
196 pd.SetValue (manager.Current, data);
199 private void CurrentChangedHandler ()
201 if (changed_event != null) {
202 changed_event.RemoveEventHandler (event_current, property_value_changed_handler);
203 WirePropertyValueChangedEvent ();
207 private void WirePropertyValueChangedEvent ()
209 EventDescriptor changed_event = TypeDescriptor.GetEvents (manager.Current).Find (property_name + "Changed", false);
210 if (changed_event == null)
212 property_value_changed_handler = new EventHandler (PropertyValueChanged);
213 changed_event.AddEventHandler (manager.Current, property_value_changed_handler);
215 event_current = manager.Current;
218 private void PropertyValueChanged (object sender, EventArgs e)
223 private void ControlValidatingHandler (object sender, CancelEventArgs e)
228 private object ParseData (object data, Type data_type)
230 ConvertEventArgs e = new ConvertEventArgs (data, data_type);
233 if (data_type.IsAssignableFrom (e.Value.GetType ()))
235 if (e.Value == Convert.DBNull)
238 return ConvertData (e.Value, data_type);
241 private object FormatData (object data)
243 if (data_type == typeof (object))
246 ConvertEventArgs e = new ConvertEventArgs (data, data_type);
249 if (data_type.IsAssignableFrom (e.Value.GetType ()))
252 return ConvertData (data, data_type);
255 private object ConvertData (object data, Type data_type)
257 TypeConverter converter = TypeDescriptor.GetConverter (data.GetType ());
258 if (converter != null && converter.CanConvertTo (data_type))
259 return converter.ConvertTo (data, data_type);
261 if (data is IConvertible) {
262 object res = Convert.ChangeType (data, data_type);
263 if (data_type.IsAssignableFrom (res.GetType ()))
271 public event ConvertEventHandler Format;
272 public event ConvertEventHandler Parse;