MyColorIOS.cs

// Written by Alexander Lyons 2013.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Monotouch.CoreGraphics;
using Monotouch.UIKit;

namespace YourNamespace.Graphics // We used the Graphics so that we could have 'using Lume.Graphics;' and have access to the color pallette
{
    public enum ColorTheme
    {
        Light,
        Dark,
        Normal
    }

    public class MyColor
    {
        #region Variables
        protected static MyColor _me;
        protected static ColorTheme theme;
        protected static Dictionary<string, UIColor> normalColors;
        protected static Dictionary<string, UIColor> lightColors;
        protected static Dictionary<string, UIColor> darkColors;
        #endregion

        #region Properties
        public static ColorTheme Theme
        {
            get { return theme; }
            set
            {
                if (theme != value)
                {
                    theme = value;
                    SaveCurrentTheme();// We had logic here to save the theme choice to the database;
                }
            }
        }
        public static UIColor Background
        {
            get
            {
                switch(Theme)
                {
                    case ColorTheme.Light: return lightColors["background"];
                    case ColorTheme.Dark: return darkColors["background"];
                    default: return normalColors["background"];
                }
            }
        }
        public static UIColor Text
        {
            get
            {
                switch(Theme)
                {
                    case ColorTheme.Light: return lightColors["text"];
                    case ColorTheme.Dark: return darkColors["text"];
                    default: return normalColors["text"];
                }
            }
        }
        public static UIColor Confirm
        {
            get
            {
                switch(Theme)
                {
                    case ColorTheme.Light: return lightColors["confirm"];
                    case ColorTheme.Dark: return darkColors["confirm"];
                    default: return normalColors["confirm"];
                }
            }
        }
        public static UIColor Decline
        {
            get
            {
                switch(Theme)
                {
                    case ColorTheme.Light: return lightColors["decline"];
                    case ColorTheme.Dark: return darkColors["decline"];
                    default: return normalColors["decline"];
                }
            }
        }
        #endregion

        #region Constructors
        static MyColor()
        {
            _me = new MyColor();
        }
        protected MyColor()
        {
            var themeSetting = Database.UserSettings.GetUserSetting(typeof(ColorTheme).ToString());
            if (themeSettng == null)
            {
                theme = ColorTheme.Normal;
            }
            else
            {
                var success = Enum.TryParse<ColorTheme>(themeSetting.Value, out theme);
                if (!success)
                {
                    theme = ColorTheme.Normal;
                }
                normalColors = new Dictionary<string, UIColor>();
                lightColors = new Dictionary<string, UIColor>();
                darkColors = new Dictionary<string, UIColor>();
                CreateColors();
            }
        }
        #endregion

        #region Methods
        static void CreateColors()
        {
            CreateNormalColors();
            CreateLightColors();
            CreateDarkColors();
        }
        static void CreateNormalColors()
        {
            normalColors.Add("background", ConvertHexToUIColor("#FAFAFA"));
            normalColors.Add("text", ConvertHexToUIColor("#2A2A2A"));
            normalColors.Add("confirm", ConvertHexToUIColor("#00EA1A"));
            normalColors.Add("decline", ConvertHexToUIColor("#E70000"));
        }
        static void CreateLightColors()
        {
            // Similar set up to normal colors.
        }
        static void CreateDarkColors()
        {
            // Similar set up to normal colors.
        }
        public static UIColor ConvertHexToUIColor(string hex)
        {
            if (hex.Contains('#')) hex = hex.Replace("#", "");
            float[] rgba = new float[] { 255.0f, 255.0f, 255.0f, 255.0f };

            if (hex.Length == 6)
            {
                rgba[0] = Convert.ToInt32(hex.Substring(0, 2), 16);
                rgba[1] = Convert.ToInt32(hex.Substring(2, 2), 16);
                rgba[2] = Convert.ToInt32(hex.Substring(4, 2), 16);
                rgba[3] = 255.0f;
            }
            else if (hex.Length == 8)
            {
                rgba[0] = Convert.ToInt32(hex.Substring(0, 2), 16);
                rgba[1] = Convert.ToInt32(hex.Substring(2, 2), 16);
                rgba[2] = Convert.ToInt32(hex.Substring(4, 2), 16);
                rgba[3] = Convert.ToInt32(hex.Substring(6, 2), 16);
            }
            else
            {
                throw new ArgumentException("Hash must be color code six or eight characters in length.");
            }

            return new UIColor(rgba[0] / 255.0f, rgba[1] / 255.0f, rgba[2] / 255.0f, rgba[3] / 255.0f);
        }
        static void SaveCurrentTheme()
        {
            Database.UserSettings.SaveUserSetting(new UserSetting(typeof(ColorTheme).ToString(), Theme.ToString()));
        }
        #endregion
    }
}