Catel - Part 4 of n: Unit testing with Catel

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="CountVisibilityConverter.cs" company="Catel development team">
//   Copyright (c) 2008 - 2011 Catel development team. All rights reserved.
// </copyright>
// <summary>
//   Convert for auto hide or collapsing of control depending on given count.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

using System;
using System.Collections;
using System.Windows;
using System.Windows.Data;

namespace Catel.Windows.Data.Converters
{
    /// <summary>
    /// Convert for auto collapsing of control depending on given count.
    /// </summary>
#if !SILVERLIGHT
    [ValueConversion(typeof(int), typeof(Visibility))]
#endif
    public class CountCollapsedConverter : VisibilityConverterBase
    {
        #region Constructor & destructor
        /// <summary>
        /// Initializes a new instance of the <see cref="CountCollapsedConverter"/> class.
        /// </summary>
        public CountCollapsedConverter()
            : base(Visibility.Collapsed) { }

        /// <summary>
        /// Initializes a new instance of the <see cref="CountCollapsedConverter"/> class.
        /// </summary>
        /// <param name="notVisibleVisibility">The <see cref="Visibility"/> state when not visibible should be returned.</param>
        /// <exception cref="ArgumentException">when <paramref name="notVisibleVisibility"/> is <see cref="Visibility.Visible"/>.</exception>
        internal CountCollapsedConverter(Visibility notVisibleVisibility)
            : base(notVisibleVisibility) { }
        #endregion

        /// <summary>
        /// Determines what value this converter should return.
        /// </summary>
        /// <param name="value">The value produced by the binding source.</param>
        /// <param name="targetType">The type of the binding target property.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        /// <returns>
        /// 	<c>true</c> if the specified value is visible; otherwise, <c>false</c>.
        /// </returns>
        public override bool IsVisible(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value == null)
            {
                return false;
            }

            bool hasContent = false;

            if (!hasContent && value is ICollection)
            {
                hasContent = ((ICollection)value).Count > 0;
            }

            if (!hasContent && value is string)
            {
                hasContent = ((string)value).Length > 0;
            }

            if (!hasContent && value is long)
            {
                hasContent = ((long)value) > 0;
            }

            if (!hasContent && value is int)
            {
                hasContent = ((int)value) > 0;
            }

            if (!hasContent && value is short)
            {
                hasContent = ((short)value) > 0;
            }

            return hasContent;
        }
    }

#if !SILVERLIGHT
    /// <summary>
    /// Convert for auto hiding of control depending on given count.
    /// </summary>
    [ValueConversion(typeof(int), typeof(Visibility))]
    public class CountHiddenConverter : CountCollapsedConverter
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="CountHiddenConverter"/> class.
        /// </summary>
        public CountHiddenConverter()
            : base(Visibility.Hidden) { }
    }
#endif
}