XClave

namespace Extensions

{

    using System;

    using System.Collections.Generic;

    using System.Collections.ObjectModel;

    using System.Linq;

    /// <summary>Extension methods for the <see cref="ObservableCollection{T}"/> class.</summary>

    public static class ObservableCollectionExtensions

    {

        /// <summary>Adds a range of items to an <see cref="ObservableCollection{T}"/>.</summary>

        /// <typeparam name="T">The type held in the <see cref="ObservableCollection{T}"/>.</typeparam>

        /// <param name="observableCollection">The <see cref="ObservableCollection{T}"/> instance to add the items to.</param>

        /// <param name="items">The items to add the <see cref="ObservableCollection{T}"/>.</param>

        /// <exception cref="ArgumentNullException">Thrown if the <paramref name="observableCollection"/> given is null.</exception>

        /// <exception cref="ArgumentNullException">Thrown if the <paramref name="items"/> given is null.</exception>

        public static void AddRange<T>(this ObservableCollection<T> observableCollection, IEnumerable<T> items)

        {

            Throw.IfNull("observableCollection", observableCollection);

            Throw.IfNull("items", items);

            foreach (T item in items)

                observableCollection.Add(item);

        }

        /// <summary>Adds a range of items to an <see cref="ObservableCollection{T}"/>.</summary>

        /// <typeparam name="T">The type held in the <see cref="ObservableCollection{T}"/>.</typeparam>

        /// <param name="observableCollection">The <see cref="ObservableCollection{T}"/> instance to add the items to.</param>

        /// <param name="items">The items to add the <see cref="ObservableCollection{T}"/>.</param>

        /// <param name="filter">A filter to use to select specific values from the <paramref name="items"/>.</param>

        /// <exception cref="ArgumentNullException">Thrown if the <paramref name="observableCollection"/> given is null.</exception>

        /// <exception cref="ArgumentNullException">Thrown if the <paramref name="items"/> given is null.</exception>

        public static void AddRange<T>(this ObservableCollection<T> observableCollection, IEnumerable<T> items, Func<T, bool> filter)

        {

            Throw.IfNull("observableCollection", observableCollection);

            Throw.IfNull("items", items);

            foreach (T item in items.Where(filter))

                observableCollection.Add(item);

        }

        /// <summary>Adds a range of items to an <see cref="ObservableCollection{T}"/>.</summary>

        /// <typeparam name="T">The type held in the <see cref="ObservableCollection{T}"/>.</typeparam>

        /// <param name="observableCollection">The <see cref="ObservableCollection{T}"/> instance to add the items to.</param>

        /// <param name="items">The items to add the <see cref="ObservableCollection{T}"/>.</param>

        /// <param name="filter">A filter to use to select specific values from the <paramref name="items"/>.</param>

        /// <param name="transform">A transform to apply to each of the <paramref name="items"/>.</param>

        /// <exception cref="ArgumentNullException">Thrown if the <paramref name="observableCollection"/> given is null.</exception>

        /// <exception cref="ArgumentNullException">Thrown if the <paramref name="items"/> given is null.</exception>

        public static void AddRange<T>(this ObservableCollection<T> observableCollection, IEnumerable<T> items, Func<T, bool> filter, Func<T, T> transform)

        {

            Throw.IfNull("observableCollection", observableCollection);

            Throw.IfNull("items", items);

            foreach (T item in items.Where(filter))

                observableCollection.Add(transform(item));

        }

    }

}

public static class Throw

{

    /// <summary>Throws a <see cref="ArgumentNullException"/> if the given <paramref name="argumentValue"/> is null.</summary>

    /// <param name="argumentName">Name of the argument being checked.</param>

    /// <param name="argumentValue">The <see cref="object"/> argument value being checked.</param>

    /// <param name="extraMessages">Any extra user defined messages to add to the <see cref="ArgumentException.Message"/>.</param>

    /// <exception cref="ArgumentNullException">Thrown if the <paramref name="argumentValue"/> given was null.</exception>

    public static void IfNull(string argumentName, object argumentValue, params string[] extraMessages)

    {

        if(argumentValue != null)

            return;

        throw new ArgumentNullException(argumentName, MergeMessages("Argument was null.", extraMessages));

    }

}