* TextBoxBase.cs: Take HideSelection into account when

[mono-project.git] / mcs / class / Managed.Windows.Forms / System.Windows.Forms / CurrencyManager.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) 2005 Novell, Inc.
//
// Authors:
//      Jackson Harper (jackson@ximian.com)
//

using System;
using System.Data;
using System.Reflection;
using System.Collections;
using System.ComponentModel;

namespace System.Windows.Forms {
        public class CurrencyManager : BindingManagerBase {

                protected int listposition;
                protected Type finalType;

                private IList list;
                private bool binding_suspended;

                private object data_source;

                bool editing;

                internal CurrencyManager ()
                {
                }

                internal CurrencyManager (object data_source)
                {
                        SetDataSource (data_source);
                }

                public IList List {
                        get { return list; }
                }

                public override object Current {
                        get {
                                if (listposition == -1 || listposition >= list.Count)
                                        throw new IndexOutOfRangeException ("list position");
                                return list [listposition];
                        }
                }

                public override int Count {
                        get { return list.Count; }
                }

                public override int Position {
                        get {
                                return listposition;
                        } 
                        set {
                                if (value < 0)
                                        value = 0;
                                if (value == list.Count)
                                        value = list.Count - 1;
                                if (listposition == value)
                                        return;

                                if (listposition != -1)
                                        EndCurrentEdit ();

                                listposition = value;
                                OnCurrentChanged (EventArgs.Empty);
                                OnPositionChanged (EventArgs.Empty);
                        }
                }

                internal void SetDataSource (object data_source)
                {
                        if (this.data_source is IBindingList)
                                ((IBindingList)this.data_source).ListChanged -= new ListChangedEventHandler (ListChangedHandler);

                        if (data_source is IListSource)
                                data_source = ((IListSource)data_source).GetList();

                        this.data_source = data_source;
                        if (data_source != null)
                                this.finalType = data_source.GetType();

                        listposition = -1;
                        if (this.data_source is IBindingList)
                                ((IBindingList)this.data_source).ListChanged += new ListChangedEventHandler (ListChangedHandler);

                        list = (IList)data_source;

                        // XXX this is wrong.  MS invokes OnItemChanged directly, which seems to call PushData.
                        ListChangedHandler (null, new ListChangedEventArgs (ListChangedType.Reset, -1));
                }

                public override PropertyDescriptorCollection GetItemProperties ()
                {
                        if (list is Array) {
                                Type element = list.GetType ().GetElementType ();
                                return TypeDescriptor.GetProperties (element);
                        }

                        if (list is ITypedList) {
                                return ((ITypedList)list).GetItemProperties (null);
                        }

                        PropertyInfo [] props = data_source.GetType().GetProperties ();
                        for (int i = 0; i < props.Length; i++) {
                                if (props [i].Name == "Item") {
                                        Type t = props [i].PropertyType;
                                        if (t == typeof (object))
                                                continue;
                                        return GetBrowsableProperties (t);
                                }
                        }

                        if (list.Count > 0) {
                                return GetBrowsableProperties (list [0].GetType ());
                        }
                        
                        return new PropertyDescriptorCollection (null);
                }

                public override void RemoveAt (int index)
                {
                        list.RemoveAt (index);
                }

                public override void SuspendBinding ()
                {
                        binding_suspended = true;
                }
                
                public override void ResumeBinding ()
                {
                        binding_suspended = false;
                }

                internal override bool IsSuspended {
                        get { return binding_suspended; }
                }

                // XXX this needs re-addressing once DataViewManager.AllowNew is implemented
                internal bool CanAddRows {
                        get {
                                /* if we're readonly, don't even bother checking if we can add new rows */
                                if (list.IsReadOnly)
                                        return false;

                                if (list is IBindingList) {
                                        return true;
                                        //return ((IBindingList)list).AllowNew;
                                }

                                return false;
                        }
                }

                public override void AddNew ()
                {
                        if (list as IBindingList == null)
                                throw new NotSupportedException ();

                        (list as IBindingList).AddNew ();

                        EndCurrentEdit ();

                        listposition = list.Count - 1;

                        OnCurrentChanged (EventArgs.Empty);
                        OnPositionChanged (EventArgs.Empty);
                }


                void BeginEdit ()
                {
                        IEditableObject editable = Current as IEditableObject;

                        if (editable != null) {
                                try {
                                        editable.BeginEdit ();
                                        editing = true;
                                }
                                catch {
                                        /* swallow exceptions in IEditableObject.BeginEdit () */
                                }
                        }
                }

                public override void CancelCurrentEdit ()
                {
                        if (listposition == -1)
                                return;

                        IEditableObject editable = Current as IEditableObject;

                        if (editable != null) {
                                editing = false;
                                editable.CancelEdit ();
                                OnItemChanged (new ItemChangedEventArgs (Position));
                        }
                }
                
                public override void EndCurrentEdit ()
                {
                        if (listposition == -1)
                                return;

                        IEditableObject editable = Current as IEditableObject;

                        if (editable != null) {
                                editing = false;
                                editable.EndEdit ();
                        }
                }

                public void Refresh ()
                {
                        ListChangedHandler (null, new ListChangedEventArgs (ListChangedType.Reset, -1));
                }

                protected void CheckEmpty ()
                {
                        if (list == null || list.Count < 1)
                                throw new Exception ("List is empty.");
                                
                }

                protected internal override void OnCurrentChanged (EventArgs e)
                {
                        BeginEdit ();

                        if (onCurrentChangedHandler != null) {
                                onCurrentChangedHandler (this, e);
                        }
                }

                protected virtual void OnItemChanged (ItemChangedEventArgs e)
                {
                        if (ItemChanged != null)
                                ItemChanged (this, e);
                }

                protected virtual void OnPositionChanged (EventArgs e)
                {
                        if (onPositionChangedHandler != null)
                                onPositionChangedHandler (this, e);
                }

                protected internal override string GetListName (ArrayList accessors)
                {
                        if (list is ITypedList) {
                                PropertyDescriptor [] pds = null;
                                if (accessors != null) {
                                        pds = new PropertyDescriptor [accessors.Count];
                                        accessors.CopyTo (pds, 0);
                                }
                                return ((ITypedList) list).GetListName (pds);
                        }
                        else if (finalType != null) {
                                return finalType.Name;
                        }
                        return String.Empty;
                }

                protected override void UpdateIsBinding ()
                {
                        UpdateItem ();

                        foreach (Binding binding in Bindings)
                                binding.UpdateIsBinding ();
                }

                private void UpdateItem ()
                {
                        // Probably should be validating or something here
                        if (listposition != -1) {
                                EndCurrentEdit ();
                        }
                        else if (list.Count > 0) {

                                listposition = 0;
                                
                                BeginEdit ();
                        }
                }
                
                internal object this [int index] {
                        get { return list [index]; }
                }               
                
                private PropertyDescriptorCollection GetBrowsableProperties (Type t)
                {
                        Attribute [] att = new System.Attribute [1];
                        att [0] = new BrowsableAttribute (true);
                        return TypeDescriptor.GetProperties (t, att);
                }

                private void OnMetaDataChanged (EventArgs args)
                {
                        if (MetaDataChanged != null)
                                MetaDataChanged (this, args);
                }

                private void ListChangedHandler (object sender, ListChangedEventArgs e)
                {
                        switch (e.ListChangedType) {
                        case ListChangedType.PropertyDescriptorAdded:
                        case ListChangedType.PropertyDescriptorDeleted:
                        case ListChangedType.PropertyDescriptorChanged:
                                OnMetaDataChanged (EventArgs.Empty);
                                break;
                        case ListChangedType.ItemDeleted:
                                if (listposition == e.NewIndex) {
                                        listposition = e.NewIndex - 1;
                                        OnCurrentChanged (EventArgs.Empty);
                                        OnPositionChanged (EventArgs.Empty);
                                }
                                        
                                OnItemChanged (new ItemChangedEventArgs (-1));
                                break;
                        case ListChangedType.ItemAdded:
                                if (listposition == -1) {
                                        /* do we need this logic up above in ItemDeleted as well? */
                                        listposition = e.NewIndex == 0 ? 0 : e.NewIndex - 1;
                                        OnCurrentChanged (EventArgs.Empty);
                                        OnPositionChanged (EventArgs.Empty);
                                }

                                OnItemChanged (new ItemChangedEventArgs (-1));
                                break;
                        case ListChangedType.ItemChanged:
                                if (editing)
                                        OnItemChanged (new ItemChangedEventArgs (e.NewIndex));
                                break;
                        default:
                                PushData ();
                                OnItemChanged (new ItemChangedEventArgs (-1));
                                //                              UpdateIsBinding ();
                                break;
                        }
                }

                public event ItemChangedEventHandler ItemChanged;
                public event EventHandler MetaDataChanged;
        }
}