diff options
Diffstat (limited to 'mcs/class/Managed.Windows.Forms/System.Windows.Forms/Binding.cs')
| -rw-r--r-- | mcs/class/Managed.Windows.Forms/System.Windows.Forms/Binding.cs | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Binding.cs b/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Binding.cs new file mode 100644 index 00000000000..1677f2f46cd --- /dev/null +++ b/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Binding.cs @@ -0,0 +1,284 @@ +// Permission is hereby granted, free of charge, to any person obtaining +// a copy of this software and associated documentation files (the +// "Software"), to deal in the Software without restriction, including +// without limitation the rights to use, copy, modify, merge, publish, +// distribute, sublicense, and/or sell copies of the Software, and to +// permit persons to whom the Software is furnished to do so, subject to +// the following conditions: +// +// The above copyright notice and this permission notice shall be +// included in all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +// +// Copyright (c) 2004-2005 Novell, Inc. +// +// Authors: +// Peter Bartok pbartok@novell.com +// Jackson Harper jackson@ximian.com +// + + +using System.ComponentModel; + +namespace System.Windows.Forms { + + [TypeConverter (typeof (ListBindingConverter))] + public class Binding { + + private string property_name; + private object data_source; + private string data_member; + private BindingMemberInfo binding_member_info; + private Control control; + + private BindingManagerBase manager; + private PropertyDescriptor prop_desc; + private PropertyDescriptor is_null_desc; + + private EventDescriptor changed_event; + private EventHandler property_value_changed_handler; + private object event_current; // The manager.Current as far as the changed_event knows + + private object data; + private Type data_type; + + #region Public Constructors + public Binding (string propertyName, object dataSource, string dataMember) + { + property_name = propertyName; + data_source = dataSource; + data_member = dataMember; + binding_member_info = new BindingMemberInfo (dataMember); + } + #endregion // Public Constructors + + #region Public Instance Properties + public BindingManagerBase BindingManagerBase { + get { + return manager; + } + } + + public BindingMemberInfo BindingMemberInfo { + get { + return binding_member_info; + } + } + + [DefaultValue (null)] + public Control Control { + get { + return control; + } + } + + public object DataSource { + get { + return data_source; + } + } + + public bool IsBinding { + get { + if (control == null || !control.Created) + return false; + if (manager == null || manager.IsSuspended) + return false; + return true; + } + } + + [DefaultValue ("")] + public string PropertyName { + get { + return property_name; + } + } + #endregion // Public Instance Properties + + #region Protected Instance Methods + protected virtual void OnFormat (ConvertEventArgs cevent) + { + if (Format!=null) + Format (this, cevent); + } + + protected virtual void OnParse (ConvertEventArgs cevent) + { + if (Parse!=null) + Parse (this, cevent); + } + #endregion // Protected Instance Methods + + + internal void SetControl (Control control) + { + if (control == this.control) + return; + + prop_desc = TypeDescriptor.GetProperties (control).Find (property_name, true); + + if (prop_desc == null) + throw new ArgumentException (String.Concat ("Cannot bind to property '", property_name, "' on target control.")); + if (prop_desc.IsReadOnly) + throw new ArgumentException (String.Concat ("Cannot bind to property '", property_name, "' because it is read only.")); + + data_type = prop_desc.PropertyType; // Getting the PropertyType is kinda slow and it should never change, so it is cached + control.Validating += new CancelEventHandler (ControlValidatingHandler); + + this.control = control; + } + + internal void Check (BindingContext binding_context) + { + if (control == null) + return; + + manager = control.BindingContext [data_source]; + manager.AddBinding (this); + + WirePropertyValueChangedEvent (); + + is_null_desc = TypeDescriptor.GetProperties (manager.Current).Find (property_name + "IsNull", false); + + PullData (); + } + + internal void PushData () + { + if (IsBinding == false) + return; + + data = prop_desc.GetValue (control); + data = FormatData (data); + SetPropertyValue (data); + } + + internal void PullData () + { + if (IsBinding == false) + return; + + if (is_null_desc != null) { + bool is_null = (bool) is_null_desc.GetValue (manager.Current); + if (is_null) { + data = Convert.DBNull; + return; + } + } + + if (data_member != null) { + PropertyDescriptor pd = TypeDescriptor.GetProperties (manager.Current).Find (data_member, true); + object pulled = pd.GetValue (manager.Current); + data = ParseData (pulled, pd.PropertyType); + } else { + object pulled = manager.Current; + data = ParseData (pulled, pulled.GetType ()); + } + + data = FormatData (data); + SetControlValue (data); + } + + internal void UpdateIsBinding () + { + PushData (); + } + + private void SetControlValue (object data) + { + prop_desc.SetValue (control, data); + } + + private void SetPropertyValue (object data) + { + PropertyDescriptor pd = TypeDescriptor.GetProperties (manager.Current).Find (data_member, true); + if (pd.IsReadOnly) + return; + pd.SetValue (manager.Current, data); + } + + private void CurrentChangedHandler () + { + if (changed_event != null) { + changed_event.RemoveEventHandler (event_current, property_value_changed_handler); + WirePropertyValueChangedEvent (); + } + } + + private void WirePropertyValueChangedEvent () + { + EventDescriptor changed_event = TypeDescriptor.GetEvents (manager.Current).Find (property_name + "Changed", false); + if (changed_event == null) + return; + property_value_changed_handler = new EventHandler (PropertyValueChanged); + changed_event.AddEventHandler (manager.Current, property_value_changed_handler); + + event_current = manager.Current; + } + + private void PropertyValueChanged (object sender, EventArgs e) + { + PullData (); + } + + private void ControlValidatingHandler (object sender, CancelEventArgs e) + { + PullData (); + } + + private object ParseData (object data, Type data_type) + { + ConvertEventArgs e = new ConvertEventArgs (data, data_type); + + OnParse (e); + if (data_type.IsInstanceOfType (e.Value)) + return e.Value; + if (e.Value == Convert.DBNull) + return e.Value; + + return ConvertData (e.Value, data_type); + } + + private object FormatData (object data) + { + if (data_type == typeof (object)) + return data; + + ConvertEventArgs e = new ConvertEventArgs (data, data_type); + + OnFormat (e); + if (data_type.IsInstanceOfType (e.Value)) + return e.Value; + + return ConvertData (data, data_type); + } + + private object ConvertData (object data, Type data_type) + { + TypeConverter converter = TypeDescriptor.GetConverter (data.GetType ()); + if (converter != null && converter.CanConvertTo (data_type)) + return converter.ConvertTo (data, data_type); + + if (data is IConvertible) { + object res = Convert.ChangeType (data, data_type); + if (data_type.IsInstanceOfType (res)) + return res; + } + + return null; + } + + #region Events + public event ConvertEventHandler Format; + public event ConvertEventHandler Parse; + #endregion // Events + } +} |