/src/NUnit/util/SettingsGroup.cs

// ****************************************************************

// Copyright 2002-2003, Charlie Poole

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org

// ****************************************************************



namespace NUnit.Util

{

	using System;

    using System.Drawing;

    using System.Globalization;

    using System.ComponentModel;



	/// <summary>

	/// SettingsGroup is the base class representing a group

	/// of user or system settings. All storge of settings

	/// is delegated to a SettingsStorage.

	/// </summary>

	public class SettingsGroup : ISettings, IDisposable

	{

		#region Instance Fields

		protected ISettingsStorage storage;

		#endregion



		#region Constructors



		/// <summary>

		/// Construct a settings group.

		/// </summary>

		/// <param name="storage">Storage for the group settings</param>

		public SettingsGroup( ISettingsStorage storage )

		{

			this.storage = storage;

		}



		/// <summary>

		/// Protected constructor for use by derived classes that

		/// set the storage themselves or don't use a storage.

		/// </summary>

		protected SettingsGroup()

		{

		}

		#endregion



		#region Properties



		public event SettingsEventHandler Changed;



		/// <summary>

		/// The storage used for the group settings

		/// </summary>

		public ISettingsStorage Storage

		{

			get { return storage; }

		}



		#endregion



		#region ISettings Members



		/// <summary>

		/// Load the value of one of the group's settings

		/// </summary>

		/// <param name="settingName">Name of setting to load</param>

		/// <returns>Value of the setting or null</returns>

		public object GetSetting( string settingName )

		{

			return storage.GetSetting( settingName );

		}



		/// <summary>

		/// Load the value of one of the group's settings or return a default value

		/// </summary>

		/// <param name="settingName">Name of setting to load</param>

		/// <param name="defaultValue">Value to return if the seeting is not present</param>

		/// <returns>Value of the setting or the default</returns>

		public object GetSetting( string settingName, object defaultValue )

		{

			object result = GetSetting(settingName );



			if ( result == null )

				result = defaultValue;



			return result;

		}



        /// <summary>

        /// Load the value of one of the group's integer settings

        /// in a type-safe manner or return a default value

        /// </summary>

        /// <param name="settingName">Name of setting to load</param>

        /// <param name="defaultValue">Value to return if the seeting is not present</param>

        /// <returns>Value of the setting or the default</returns>

        public int GetSetting(string settingName, int defaultValue)

        {

            object result = GetSetting(settingName);



            if (result == null)

                return defaultValue;



            if (result is int)

                return (int)result;



            try

            {

                return Int32.Parse(result.ToString());

            }

            catch

            {

                return defaultValue;

            }

        }



        /// <summary>

        /// Load the value of one of the group's float settings

        /// in a type-safe manner or return a default value

        /// </summary>

        /// <param name="settingName">Name of setting to load</param>

        /// <param name="defaultValue">Value to return if the setting is not present</param>

        /// <returns>Value of the setting or the default</returns>

        public float GetSetting(string settingName, float defaultValue)

        {

            object result = GetSetting(settingName);



            if (result == null)

                return defaultValue;



            if (result is float)

                return (float)result;



            try

            {

                return float.Parse(result.ToString());

            }

            catch

            {

                return defaultValue;

            }

        }



        /// <summary>

		/// Load the value of one of the group's boolean settings

		/// in a type-safe manner.

		/// </summary>

		/// <param name="settingName">Name of setting to load</param>

		/// <param name="defaultValue">Value of the setting or the default</param>

		/// <returns>Value of the setting</returns>

		public bool GetSetting( string settingName, bool defaultValue )

		{

			object result = GetSetting(settingName );



			if ( result == null )

				return defaultValue;



			// Handle legacy formats

//			if ( result is int )

//				return (int)result == 1;

//

//			if ( result is string )

//			{

//				if ( (string)result == "1" ) return true;

//				if ( (string)result == "0" ) return false;

//			}



			if ( result is bool )

				return (bool) result ;

			

			try

			{

				return Boolean.Parse( result.ToString() );

			}

			catch

			{

				return defaultValue;

			}

		}



		/// <summary>

		/// Load the value of one of the group's string settings

		/// in a type-safe manner or return a default value

		/// </summary>

		/// <param name="settingName">Name of setting to load</param>

		/// <param name="defaultValue">Value to return if the setting is not present</param>

		/// <returns>Value of the setting or the default</returns>

		public string GetSetting( string settingName, string defaultValue )

		{

			object result = GetSetting(settingName );



			if ( result == null )

				return defaultValue;



			if ( result is string )

				return (string) result;

			else

				return result.ToString();

		}



        /// <summary>

        /// Load the value of one of the group's enum settings

        /// in a type-safe manner or return a default value

        /// </summary>

        /// <param name="settingName">Name of setting to load</param>

        /// <param name="defaultValue">Value to return if the setting is not present</param>

        /// <returns>Value of the setting or the default</returns>

        public System.Enum GetSetting(string settingName, System.Enum defaultValue)

        {

            object result = GetSetting(settingName);



            if (result == null)

                return defaultValue;



            if (result is System.Enum)

                return (System.Enum)result;



            try

            {

                return (System.Enum)System.Enum.Parse(defaultValue.GetType(), result.ToString(), true);

            }

            catch

            {

                return defaultValue;

            }

        }



        /// <summary>

        /// Load the value of one of the group's Font settings

        /// in a type-safe manner or return a default value

        /// </summary>

        /// <param name="settingName">Name of setting to load</param>

        /// <param name="defaultFont">Value to return if the setting is not present</param>

        /// <returns>Value of the setting or the default</returns>

        public Font GetSetting(string settingName, Font defaultFont)

        {

            object result = GetSetting(settingName);



            if (result == null)

                return defaultFont;



            if (result is Font)

                return (Font)result;



            try

            {

                TypeConverter converter = TypeDescriptor.GetConverter(typeof(Font));

                return (Font)converter.ConvertFrom(null, CultureInfo.InvariantCulture, result.ToString());

            }

            catch

            {

                return defaultFont;

            }

        }



        /// <summary>

		/// Remove a setting from the group

		/// </summary>

		/// <param name="settingName">Name of the setting to remove</param>

		public void RemoveSetting( string settingName )

		{

			storage.RemoveSetting( settingName );



			if ( Changed != null )

				Changed( this, new SettingsEventArgs( settingName ) );

		}



		/// <summary>

		/// Remove a group of settings

		/// </summary>

		/// <param name="GroupName"></param>

		public void RemoveGroup( string groupName )

		{

			storage.RemoveGroup( groupName );

		}



		/// <summary>

		/// Save the value of one of the group's settings

		/// </summary>

		/// <param name="settingName">Name of the setting to save</param>

		/// <param name="settingValue">Value to be saved</param>

		public void SaveSetting( string settingName, object settingValue )

		{

			object oldValue = storage.GetSetting( settingName );



			// Avoid signaling "changes" when there is not really a change

			if ( oldValue != null )

			{

				if( oldValue is string && settingValue is string && (string)oldValue == (string)settingValue ||

					oldValue is int && settingValue is int && (int)oldValue == (int)settingValue ||

					oldValue is bool && settingValue is bool && (bool)oldValue == (bool)settingValue ||

					oldValue is Enum && settingValue is Enum && oldValue.Equals(settingValue) )

					return;

			}



			storage.SaveSetting( settingName, settingValue );



			if ( Changed != null )

				Changed( this, new SettingsEventArgs( settingName ) );

		}

		#endregion



		#region IDisposable Members

		/// <summary>

		/// Dispose of this group by disposing of it's storage implementation

		/// </summary>

		public void Dispose()

		{

			if ( storage != null )

			{

				storage.Dispose();

				storage = null;

			}

		}

		#endregion

	}

}