#region License

/*
 * Copyright © 2002-2005 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#endregion

#region Imports

using System.Collections;

#endregion

namespace Spring.Objects
{
    /// <summary>
    /// A collection style container for <see cref="Spring.Objects.PropertyValue"/>
    /// instances.
    /// </summary>
    /// <author>Rod Johnson</author>
    /// <author>Mark Pollack (.NET) </author>
    public interface IPropertyValues : IEnumerable
    {
        /// <summary>
        /// Return an array of the <see cref="Spring.Objects.PropertyValue"/> objects
        /// held in this object.</summary>
        /// <returns>
        /// An array of the <see cref="Spring.Objects.PropertyValue"/> objects held
        /// in this object.
        /// </returns>
        PropertyValue [] PropertyValues
        {
            get;
        }
		
        /// <summary>
        /// Return the <see cref="Spring.Objects.PropertyValue"/> instance with the
        /// given name.
        /// </summary>
        /// <param name="propertyName">The name to search for.</param>
        /// <returns>the <see cref="Spring.Objects.PropertyValue"/>, or null if a 
        /// the <see cref="Spring.Objects.PropertyValue"/> with the supplied
        /// <paramref name="propertyName"/> did not exist in this collection.
        /// </returns>
        PropertyValue GetPropertyValue(string propertyName);
		
        /// <summary>
        /// Is there a <see cref="Spring.Objects.PropertyValue"/> instance for this
        /// property name?
        /// </summary>
        /// <param name="propertyName">The name to search for.</param>
        /// <returns>
        /// True if there is a <see cref="Spring.Objects.PropertyValue"/> instance for
        /// the supplied <paramref name="propertyName"/>.
        /// </returns>
        bool Contains(string propertyName);
		
        /// <summary>
        /// Return the difference (changes, additions, but not removals) of
        /// property values between the supplied argument and the values
        /// contained in the collection.
        /// </summary>
        /// <remarks>
        /// <p>
        /// Subclasses should also override <c>Equals</c>.
        /// </p>
        /// </remarks>
        /// <param name="old">The old property values.</param>
        /// <returns>
        /// An <see cref="Spring.Objects.IPropertyValues"/> containing any changes, or
        /// an empty <see cref="Spring.Objects.IPropertyValues"/> instance if there were
        /// no changes.
        /// </returns>
        IPropertyValues ChangesSince (IPropertyValues old);
    }
}
