(DISTFILES): Comment out a few missing files.

[mono-project.git] / mcs / class / System.Data / System.Data / Constraint.cs

//
// System.Data.Constraint.cs
//
// Author:
//      Franklin Wise <gracenote@earthlink.net>
//      Daniel Morgan
//      Tim Coleman (tim@timcoleman.com)
//   
//
// (C) Ximian, Inc. 2002
// Copyright (C) Tim Coleman, 2002
//

//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// 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.
//

using System;
using System.Collections;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Runtime.Serialization;

namespace System.Data {
        [Serializable]
        internal delegate void DelegateConstraintNameChange (object sender, string newName);

        [DefaultProperty ("ConstraintName")]    
        [Serializable]
        [TypeConverterAttribute (typeof (ConstraintConverter))]
        public abstract class Constraint 
        {
                internal event DelegateConstraintNameChange BeforeConstraintNameChange;

                //if constraintName is not set then a name is 
                //created when it is added to
                //the ConstraintCollection
                //it can not be set to null, empty or duplicate
                //once it has been added to the collection
                private string _constraintName;
                private PropertyCollection _properties;

                private Index _index;

                //Used for membership checking
                private ConstraintCollection _constraintCollection;

                DataSet dataSet;

                protected Constraint () 
                {
                        dataSet = null;
                        _properties = new PropertyCollection();
                }

                [CLSCompliant (false)]
                protected internal virtual DataSet _DataSet {
                        get { return dataSet; }
                }

                [DataCategory ("Data")]
                [DataSysDescription ("Indicates the name of this constraint.")]
                [DefaultValue ("")]
                public virtual string ConstraintName {
                        get{ return _constraintName == null ? "" : _constraintName; } 
                        set{
                                //This should only throw an exception when it
                                //is a member of a ConstraintCollection which
                                //means we should let the ConstraintCollection
                                //handle exceptions when this value changes
                                _onConstraintNameChange(value);
                                _constraintName = value;
                        }
                }

                [Browsable (false)]
                [DataCategory ("Data")]
                [DataSysDescription ("The collection that holds custom user information.")]
                public PropertyCollection ExtendedProperties {
                        get { return _properties; }
                }

                [DataSysDescription ("Indicates the table of this constraint.")]
                public abstract DataTable Table {
                        get;
                }

                internal ConstraintCollection ConstraintCollection {
                        get{ return _constraintCollection; }
                        set{ _constraintCollection = value; }
                }
                
                private void _onConstraintNameChange (string newName)
                {
                        if (null != BeforeConstraintNameChange)
                        {
                                BeforeConstraintNameChange (this, newName);
                        }
                }

                //call once before adding a constraint to a collection
                //will throw an exception to prevent the add if a rule is broken
                internal virtual void AddToConstraintCollectionSetup (ConstraintCollection collection)
                {
                }
                                        
                internal virtual void AssertConstraint ()
                {
                }
                
                internal virtual void AssertConstraint (DataRow row)
                {
                }

                internal virtual void RollbackAssert (DataRow row)
                {
                }

                //call once before removing a constraint to a collection
                //can throw an exception to prevent the removal
                internal virtual void RemoveFromConstraintCollectionCleanup (ConstraintCollection collection)
                {
                }

                [MonoTODO]
                protected void CheckStateForProperty ()
                {
                        throw new NotImplementedException ();
                }

                protected internal void SetDataSet (DataSet dataSet)
                {
                        this.dataSet = dataSet;
                }

                internal Index Index
                {
                        get {
                                return _index;
                        }
                        set {
                                _index = value;
                        }
                }

                internal void UpdateIndex (DataRow row)
                {
                        if (row.RowState == DataRowState.Detached || row.RowState == DataRowState.Unchanged)
                                Index.Insert (new Node (row), DataRowVersion.Default);
                        else if ((row.RowState == DataRowState.Modified) || (row.RowState == DataRowState.Added)) {
                                // first we check if the values of the key changed.
                                bool keyChanged = false;
                                for (int i = 0; i < Index.Columns.Length; i++) {
                                        if (row[Index.Columns[i], DataRowVersion.Default] != row[Index.Columns[i], DataRowVersion.Current]) {
                                                keyChanged = true;
                                        }
                                }
                                // if key changed we first try to insert a new node 
                                // and,if succeded, we delete the row's old node.
                                if (keyChanged) 
                                {
                                        // insert new node for the row
                                        // note : may throw if not succeded
                                        Index.Insert (new Node (row), DataRowVersion.Default);

                                        // delete the row's node
                                        Index.Delete(row);                                      
                                }
                        }
                }

                internal void RollbackIndex (DataRow row)
                {
                        Node n = Index.Find(row, DataRowVersion.Default);
                        if ( n == null)
                                throw new ConstraintException("Row was not found in constraint index");

                        // first remove the node inserted as a result of last AssertConstraint on the row 
                        Index.Delete(n);
                        
                        // if the row is not detached we should add back to the index 
                        // node corresponding to row value before AssertConstraint was called
                        if(row.RowState != DataRowState.Detached){
                                // since index before we updated index was ok, insert should always suceed
                                // maybe we still need to try/catch here
                                Index.Insert(new Node(row), DataRowVersion.Current);
                        }
                }


                /// <summary>
                /// Gets the ConstraintName, if there is one, as a string. 
                /// </summary>
                public override string ToString () 
                {
                        return _constraintName == null ? "" : _constraintName;
                }

        }
}