[LoongArch64] Part-5:add loongarch support in some files for LoongArch64. (#21769)

[mono-project.git] / mcs / class / System.Windows.Forms / System.Windows.Forms / Binding.cs

// 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 bool is_binding;
                private bool checked_isnull;

                private BindingMemberInfo binding_member_info;
                private IBindableComponent control;

                private BindingManagerBase manager;
                private PropertyDescriptor control_property;
                private PropertyDescriptor is_null_desc;

                private object data;
                private Type data_type;

                private DataSourceUpdateMode datasource_update_mode;
                private ControlUpdateMode control_update_mode;
                private object datasource_null_value = Convert.DBNull;
                private object null_value;
                private IFormatProvider format_info;
                private string format_string;
                private bool formatting_enabled;
                #region Public Constructors
                public Binding (string propertyName, object dataSource, string dataMember) 
                        : this (propertyName, dataSource, dataMember, false, DataSourceUpdateMode.OnValidation, null, string.Empty, null)
                {
                }
                
                public Binding (string propertyName, object dataSource, string dataMember, bool formattingEnabled)
                        : this (propertyName, dataSource, dataMember, formattingEnabled, DataSourceUpdateMode.OnValidation, null, string.Empty, null)
                {
                }
                
                public Binding (string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode dataSourceUpdateMode)
                        : this (propertyName, dataSource, dataMember, formattingEnabled, dataSourceUpdateMode, null, string.Empty, null)
                {
                }
                
                public Binding (string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode dataSourceUpdateMode, object nullValue)
                        : this (propertyName, dataSource, dataMember, formattingEnabled, dataSourceUpdateMode, nullValue, string.Empty, null)
                {
                }

                public Binding (string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode dataSourceUpdateMode, object nullValue, string formatString)
                        : this (propertyName, dataSource, dataMember, formattingEnabled, dataSourceUpdateMode, nullValue, formatString, null)
                {
                }

                public Binding (string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode dataSourceUpdateMode, object nullValue, string formatString, IFormatProvider formatInfo)
                {
                        property_name = propertyName;
                        data_source = dataSource;
                        data_member = dataMember;
                        binding_member_info = new BindingMemberInfo (dataMember);
                        datasource_update_mode = dataSourceUpdateMode;
                        null_value = nullValue;
                        format_string = formatString;
                        format_info = formatInfo;
                }
                #endregion      // Public Constructors

                #region Public Instance Properties
                [DefaultValue (null)]
                public IBindableComponent BindableComponent {
                        get {
                                return control;
                        }
                }

                public BindingManagerBase BindingManagerBase {
                        get {
                                return manager;
                        }
                }

                public BindingMemberInfo BindingMemberInfo {
                        get {
                                return binding_member_info;
                        }
                }

                [DefaultValue (null)]
                public Control Control {
                        get {
                                return control as Control;
                        }
                }

                [DefaultValue (ControlUpdateMode.OnPropertyChanged)]
                public ControlUpdateMode ControlUpdateMode {
                        get {
                                return control_update_mode;
                        }
                        set {
                                control_update_mode = value;
                        }
                }

                public object DataSource {
                        get {
                                return data_source;
                        }
                }

                [DefaultValue (DataSourceUpdateMode.OnValidation)]
                public DataSourceUpdateMode DataSourceUpdateMode {
                        get {
                                return datasource_update_mode;
                        }
                        set {
                                datasource_update_mode = value;
                        }
                }

                public object DataSourceNullValue {
                        get {
                                return datasource_null_value;
                        }
                        set {
                                datasource_null_value = value;
                        }
                }

                [DefaultValue (false)]
                public bool FormattingEnabled {
                        get {
                                return formatting_enabled;
                        }
                        set {
                                if (formatting_enabled == value)
                                        return;

                                formatting_enabled = value;
                                PushData ();
                        }
                }

                [DefaultValue (null)]
                public IFormatProvider FormatInfo {
                        get {
                                return format_info;
                        }
                        set {
                                if (value == format_info)
                                        return;

                                format_info = value;
                                if (formatting_enabled)
                                        PushData ();
                        }
                }

                public string FormatString {
                        get {
                                return format_string;
                        }
                        set {
                                if (value == null)
                                        value = String.Empty;
                                if (value == format_string)
                                        return;

                                format_string = value;
                                if (formatting_enabled)
                                        PushData ();
                        }
                }

                public bool IsBinding {
                        get {
                                if (manager == null || manager.IsSuspended)
                                        return false;

                                return is_binding;
                        }
                }

                public object NullValue {
                        get {
                                return null_value;
                        }
                        set {
                                if (value == null_value)
                                        return;

                                null_value = value;
                                if (formatting_enabled)
                                        PushData ();
                        }
                }

                [DefaultValue ("")]
                public string PropertyName {
                        get {
                                return property_name;
                        }
                }
                #endregion      // Public Instance Properties

                public void ReadValue ()
                {
                        PushData (true);
                }

                public void WriteValue ()
                {
                        PullData (true);
                }

                #region Protected Instance Methods
                protected virtual void OnBindingComplete (BindingCompleteEventArgs e)
                {
                        if (BindingComplete != null)
                                BindingComplete (this, e);
                }

                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 string DataMember {
                        get { return data_member; }
                }
                
                internal void SetControl (IBindableComponent control)
                {
                        if (control == this.control)
                                return;

                        control_property = TypeDescriptor.GetProperties (control).Find (property_name, true);                   

                        if (control_property == null)
                                throw new ArgumentException (String.Concat ("Cannot bind to property '", property_name, "' on target control."));
                        if (control_property.IsReadOnly)
                                throw new ArgumentException (String.Concat ("Cannot bind to property '", property_name, "' because it is read only."));
                                
                        data_type = control_property.PropertyType; // Getting the PropertyType is kinda slow and it should never change, so it is cached

                        Control ctrl = control as Control;
                        if (ctrl != null) {
                                ctrl.Validating += new CancelEventHandler (ControlValidatingHandler);
                                if (!ctrl.IsHandleCreated)
                                        ctrl.HandleCreated += new EventHandler (ControlCreatedHandler);
                        }

                        EventDescriptor prop_changed_event = GetPropertyChangedEvent (control, property_name);
                        if (prop_changed_event != null)
                                prop_changed_event.AddEventHandler (control, new EventHandler (ControlPropertyChangedHandler));
                        this.control = control;
                        UpdateIsBinding ();
                }

                internal void Check ()
                {
                        if (control == null || control.BindingContext == null)
                                return;

                        if (manager == null) {
                                manager = control.BindingContext [data_source, binding_member_info.BindingPath];

                                if (manager.Position > -1 && binding_member_info.BindingField != String.Empty &&
                                        TypeDescriptor.GetProperties (manager.Current).Find (binding_member_info.BindingField, true) == null)
                                        throw new ArgumentException ("Cannot bind to property '" + binding_member_info.BindingField + "' on DataSource.", 
                                                        "dataMember");

                                manager.AddBinding (this);
                                manager.PositionChanged += new EventHandler (PositionChangedHandler);

                                if (manager is PropertyManager) { // Match .net, which only watchs simple objects
                                        EventDescriptor prop_changed_event = GetPropertyChangedEvent (manager.Current, binding_member_info.BindingField);
                                        if (prop_changed_event != null)
                                                prop_changed_event.AddEventHandler (manager.Current, new EventHandler (SourcePropertyChangedHandler));
                                }
                        }

                        if (manager.Position == -1)
                                return;

                        if (!checked_isnull) {
                                is_null_desc = TypeDescriptor.GetProperties (manager.Current).Find (property_name + "IsNull", false);
                                checked_isnull = true;
                        }

                        PushData ();
                }

                internal bool PullData ()
                {
                        return PullData (false);
                }

                // Return false ONLY in case of error - and return true even in cases
                // where no update was possible
                bool PullData (bool force)
                {
                        if (IsBinding == false || manager.Current == null)
                                return true;
                        if (!force && datasource_update_mode == DataSourceUpdateMode.Never)
                                return true;

                        data = control_property.GetValue (control);
                        if (data == null)
                                data = datasource_null_value;

                        try {
                                SetPropertyValue (data);
                        } catch (Exception e) {
                                if (formatting_enabled) {
                                        FireBindingComplete (BindingCompleteContext.DataSourceUpdate, e, e.Message);
                                        return false;
                                }
                                throw e;
                        }

                        if (formatting_enabled)
                                FireBindingComplete (BindingCompleteContext.DataSourceUpdate, null, null);
                        return true;
                }

                internal void PushData ()
                {
                        PushData (false);
                }

                void PushData (bool force)
                {
                        if (manager == null || manager.IsSuspended || manager.Count == 0 || manager.Position == -1)
                                return;
                        if (!force && control_update_mode == ControlUpdateMode.Never)
                                return;

                        if (is_null_desc != null) {
                                bool is_null = (bool) is_null_desc.GetValue (manager.Current);
                                if (is_null) {
                                        data = Convert.DBNull;
                                        return;
                                }
                        }

                        PropertyDescriptor pd = TypeDescriptor.GetProperties (manager.Current).Find (binding_member_info.BindingField, true);
                        if (pd == null) {
                                data = manager.Current;
                        } else {
                                data = pd.GetValue (manager.Current);
                        }

                        if ((data == null || data == DBNull.Value) && null_value != null)
                                data = null_value;

                        try {
                                data = FormatData (data);
                                SetControlValue (data);
                        } catch (Exception e) {
                                if (formatting_enabled) {
                                        FireBindingComplete (BindingCompleteContext.ControlUpdate, e, e.Message);
                                        return;
                                }
                                throw e;
                        }

                        if (formatting_enabled)
                                FireBindingComplete (BindingCompleteContext.ControlUpdate, null, null);
                }

                internal void UpdateIsBinding ()
                {
                        is_binding = false;
                        if (control == null || (control is Control && !((Control)control).IsHandleCreated))
                                return;

                        is_binding = true;
                        PushData ();
                }

                private void SetControlValue (object data)
                {
                        control_property.SetValue (control, data);
                }

                private void SetPropertyValue (object data)
                {
                        PropertyDescriptor pd = TypeDescriptor.GetProperties (manager.Current).Find (binding_member_info.BindingField, true);
                        if (pd.IsReadOnly)
                                return;
                        data = ParseData (data, pd.PropertyType);
                        pd.SetValue (manager.Current, data);
                }

                private void ControlValidatingHandler (object sender, CancelEventArgs e)
                {
                        if (datasource_update_mode != DataSourceUpdateMode.OnValidation)
                                return;

                        bool ok = true;
                        // If the data doesn't seem to be valid (it can't be converted,
                        // is the wrong type, etc, we reset to the old data value.
                        // If Formatting is enabled, no exception is fired, but we get a false value
                        try {
                                ok = PullData ();
                        } catch {
                                ok = false;
                        }

                        e.Cancel = !ok;
                }

                private void ControlCreatedHandler (object o, EventArgs args)
                {
                        UpdateIsBinding ();
                }

                private void PositionChangedHandler (object sender, EventArgs e)
                {
                        Check ();
                        PushData ();
                }

                EventDescriptor GetPropertyChangedEvent (object o, string property_name)
                {
                        if (o == null || property_name == null || property_name.Length == 0)
                                return null;

                        string event_name = property_name + "Changed";
                        Type event_handler_type = typeof (EventHandler);

                        EventDescriptor prop_changed_event = null;
                        foreach (EventDescriptor event_desc in TypeDescriptor.GetEvents (o)) {
                                if (event_desc.Name == event_name && event_desc.EventType == event_handler_type) {
                                        prop_changed_event = event_desc;
                                        break;
                                }
                        }

                        return prop_changed_event;
                }

                void SourcePropertyChangedHandler (object o, EventArgs args)
                {
                        PushData ();
                }

                void ControlPropertyChangedHandler (object o, EventArgs args)
                {
                        if (datasource_update_mode != DataSourceUpdateMode.OnPropertyChanged)
                                return;

                        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;
                        if (e.Value == null) {
                                bool nullable = data_type.IsGenericType && !data_type.ContainsGenericParameters &&
                                        data_type.GetGenericTypeDefinition () == typeof (Nullable<>);
                                return data_type.IsValueType && !nullable ? Convert.DBNull : null;
                        }

                        return ConvertData (e.Value, data_type);
                }

                private object FormatData (object data)
                {
                        ConvertEventArgs e = new ConvertEventArgs (data, data_type);

                        OnFormat (e);
                        if (data_type.IsInstanceOfType (e.Value))
                                return e.Value;

                        if (formatting_enabled) {
                                if ((e.Value == null || e.Value == Convert.DBNull) && null_value != null)
                                        return null_value;
                                
                                if (e.Value is IFormattable && data_type == typeof (string)) {
                                        IFormattable formattable = (IFormattable) e.Value;
                                        return formattable.ToString (format_string, format_info);
                                }
                        }

                        if (e.Value == null && data_type == typeof (object))
                                return Convert.DBNull;

                        return ConvertData (data, data_type);
                }

                private object ConvertData (object data, Type data_type)
                {
                        if (data == null)
                                return null;

                        TypeConverter converter = TypeDescriptor.GetConverter (data.GetType ());
                        if (converter != null && converter.CanConvertTo (data_type))
                                return converter.ConvertTo (data, data_type);

                        converter = TypeDescriptor.GetConverter (data_type);
                        if (converter != null && converter.CanConvertFrom (data.GetType()))
                                return converter.ConvertFrom (data);

                        if (data is IConvertible) {
                                object res = Convert.ChangeType (data, data_type);
                                if (data_type.IsInstanceOfType (res))
                                        return res;
                        }

                        return null;
                }
                void FireBindingComplete (BindingCompleteContext context, Exception exc, string error_message)
                {
                        BindingCompleteEventArgs args = new BindingCompleteEventArgs (this, 
                                        exc == null ? BindingCompleteState.Success : BindingCompleteState.Exception,
                                        context);
                        if (exc != null) {
                                args.SetException (exc);
                                args.SetErrorText (error_message);
                        }

                        OnBindingComplete (args);
                }

                #region Events
                public event ConvertEventHandler Format;
                public event ConvertEventHandler Parse;
                public event BindingCompleteEventHandler BindingComplete;
                #endregion      // Events
        }
}