ASP.NET Web Forms Controls - How to implement the Theme Selector control shown in DevExpress Demos

C#
using System;
using System.Collections;
using System.Collections.Generic;
using System.Xml.Serialization;
using System.Web.UI;



public class ThemeGroupModel : ThemeModelBase {
    List<ThemeModel> _themes = new List<ThemeModel>();
    string _float;
    [XmlElement(ElementName = "Theme")]
    public List<ThemeModel> Themes {
        get { return _themes; }
        set { _themes = value; }
    }
    [XmlAttribute]
    public string Float {
        get { return _float; }
        set { _float = value; }
    }
}

Visual Basic
Option Infer On

Imports System
Imports System.Collections
Imports System.Collections.Generic
Imports System.Xml.Serialization
Imports System.Web.UI



Public Class ThemeGroupModel
    Inherits ThemeModelBase

    Private _themes As New List(Of ThemeModel)()
    Private _float As String
    <XmlElement(ElementName := "Theme")> _
    Public Property Themes() As List(Of ThemeModel)
        Get
            Return _themes
        End Get
        Set(ByVal value As List(Of ThemeModel))
            _themes = value
        End Set
    End Property
    <XmlAttribute> _
    Public Property Float() As String
        Get
            Return _float
        End Get
        Set(ByVal value As String)
            _float = value
        End Set
    End Property
End Class

C#
using System;
using System.Xml.Serialization;
using System.Collections.Generic;
using System.Web.UI;
using System.Drawing;



public class ThemeModel : ThemeModelBase {
    string _baseColor;
    string _fontFamily;
    string _fontSize;
    bool _showAsTop;
    string _previewColor;
    [XmlAttribute]
    public string BaseColor {
        get {
            if(String.IsNullOrEmpty(_baseColor))
                return "";
            return _baseColor;
        }
        set {
            _baseColor = value.ToUpper();
        }
    }
    [XmlAttribute]
    public bool IsNew { get; set; }
    [XmlAttribute]
    public string FontFamily {
        get {
            if(String.IsNullOrEmpty(_fontFamily))
                return "";
            return _fontFamily;
        }
        set {
            _fontFamily = value;
        }
    }
    [XmlAttribute]
    public string FontSize {
        get {
            if(String.IsNullOrEmpty(_fontSize))
                return "";
            return _fontSize;
        }
        set {
            _fontSize = value;
        }
    }
    public string Font {
        get {
            var result = string.Empty;
            if(!string.IsNullOrEmpty(FontSize) && !string.IsNullOrEmpty(FontFamily))
                result = string.Format("{0} {1}", FontSize, FontFamily);
            return result;
        }
    }
    [XmlAttribute]
    public bool ShowAsTop {
        get {
            return _showAsTop;
        }
        set {
            _showAsTop = value;
        }
    }
    [XmlAttribute]
    public string PreveiwColor {
        get {
            if(String.IsNullOrEmpty(_previewColor))
                return "";
            return _previewColor;
        }
        set {
            _previewColor = value.ToUpper();
        }
    }
}

Visual Basic
Option Infer On

Imports System
Imports System.Xml.Serialization
Imports System.Collections.Generic
Imports System.Web.UI
Imports System.Drawing



Public Class ThemeModel
    Inherits ThemeModelBase

    Private _baseColor As String
    Private _fontFamily As String
    Private _fontSize As String
    Private _showAsTop As Boolean
    Private _previewColor As String
    <XmlAttribute> _
    Public Property BaseColor() As String
        Get
            If String.IsNullOrEmpty(_baseColor) Then
                Return ""
            End If
            Return _baseColor
        End Get
        Set(ByVal value As String)
            _baseColor = value.ToUpper()
        End Set
    End Property
    <XmlAttribute> _
    Public Property IsNew() As Boolean
    <XmlAttribute> _
    Public Property FontFamily() As String
        Get
            If String.IsNullOrEmpty(_fontFamily) Then
                Return ""
            End If
            Return _fontFamily
        End Get
        Set(ByVal value As String)
            _fontFamily = value
        End Set
    End Property
    <XmlAttribute> _
    Public Property FontSize() As String
        Get
            If String.IsNullOrEmpty(_fontSize) Then
                Return ""
            End If
            Return _fontSize
        End Get
        Set(ByVal value As String)
            _fontSize = value
        End Set
    End Property
    Public ReadOnly Property Font() As String
        Get
            Dim result = String.Empty
            If Not String.IsNullOrEmpty(FontSize) AndAlso Not String.IsNullOrEmpty(FontFamily) Then
                result = String.Format("{0} {1}", FontSize, FontFamily)
            End If
            Return result
        End Get
    End Property
    <XmlAttribute> _
    Public Property ShowAsTop() As Boolean
        Get
            Return _showAsTop
        End Get
        Set(ByVal value As Boolean)
            _showAsTop = value
        End Set
    End Property
    <XmlAttribute> _
    Public Property PreveiwColor() As String
        Get
            If String.IsNullOrEmpty(_previewColor) Then
                Return ""
            End If
            Return _previewColor
        End Get
        Set(ByVal value As String)
            _previewColor = value.ToUpper()
        End Set
    End Property
End Class

C#
using System;
using System.Xml.Serialization;
using System.Collections.Generic;


public class ThemeModelBase {
    string _name;
    string _title;
    [XmlAttribute]
    public string Name {
        get {
            if(_name == null)
                return "";
            return _name;
        }
        set { _name = value; }
    }
    [XmlAttribute]
    public string Title {
        get {
            if(_title == null)
                return "";
            return _title;
        }
        set { _title = value; }
    }
}

Visual Basic
Option Infer On

Imports System
Imports System.Xml.Serialization
Imports System.Collections.Generic


Public Class ThemeModelBase
    Private _name As String
    Private _title As String
    <XmlAttribute> _
    Public Property Name() As String
        Get
            If _name Is Nothing Then
                Return ""
            End If
            Return _name
        End Get
        Set(ByVal value As String)
            _name = value
        End Set
    End Property
    <XmlAttribute> _
    Public Property Title() As String
        Get
            If _title Is Nothing Then
                Return ""
            End If
            Return _title
        End Get
        Set(ByVal value As String)
            _title = value
        End Set
    End Property
End Class

C#
using System.Xml.Serialization;
using System.Collections.Generic;
using System.IO;
using System.Web;
using System.Linq;


[XmlRoot("Themes")]
public class ThemesModel {
    const string ResourceName = "DevExpress.Web.Demos.Data.Themes.xml";
    static ThemesModel _current;
    static readonly object _currentLock = new object();
    public static ThemesModel Current {
        get {
            lock(_currentLock) {
                if(_current == null) {
                    using(Stream stream = File.OpenRead(HttpContext.Current.Server.MapPath("~/App_Data/Themes.xml"))) {
                        XmlSerializer serializer = new XmlSerializer(typeof(ThemesModel));
                        _current = (ThemesModel)serializer.Deserialize(stream);
                    }
                }
                return _current;
            }
        }
    }
    List<ThemeGroupModel> _groups = new List<ThemeGroupModel>();
    public static IEnumerable<string> MobileThemes { get { return Current.Groups.First(g => g.Name == "Mobile").Themes.Select(t => t.Name); } }
    public static IEnumerable<ThemeModel> AllThemes { get { return Current.Groups.SelectMany(g => g.Themes); } }
    public static IEnumerable<ThemeModel> NewThemes { get { return AllThemes.Where(theme => theme.IsNew); } }
    public List<ThemeGroupModel> GetAllGroups() {
        var topThemes = AllThemes.Where(t => t.ShowAsTop).ToList();
        var currentTheme = AllThemes.First(t => t.Name == Utils.CurrentTheme);
        if(!topThemes.Contains(currentTheme))
            topThemes.Add(currentTheme);
        var firstGroup = new ThemeGroupModel() {
            Name = "FirstGroup",
            Themes = topThemes
        };
        return Groups.Concat(new[] { firstGroup }).ToList();
    }
    [XmlElement("ThemeGroup")]
    public List<ThemeGroupModel> Groups {
        get { return _groups; }
    }
    public List<ThemeGroupModel> LeftGroups {
        get { return (from g in Groups where g.Float == "Left" select g).ToList(); }
    }
    public List<ThemeGroupModel> RightGroups {
        get { return (from g in Groups where g.Float == "Right" select g).ToList(); }
    }
    public static ThemeModel GetThemeModel(string themeName) {
        return Current.Groups.SelectMany(g => g.Themes).FirstOrDefault(t => t.Name == themeName);
    }
}

Visual Basic
Option Infer On

Imports System.Xml.Serialization
Imports System.Collections.Generic
Imports System.IO
Imports System.Web
Imports System.Linq


<XmlRoot("Themes")> _
Public Class ThemesModel
    Private Const ResourceName As String = "DevExpress.Web.Demos.Data.Themes.xml"
    Private Shared _current As ThemesModel
    Private Shared ReadOnly _currentLock As New Object()
    Public Shared ReadOnly Property Current() As ThemesModel
        Get
            SyncLock _currentLock
                If _current Is Nothing Then
                    Using stream As Stream = File.OpenRead(HttpContext.Current.Server.MapPath("~/App_Data/Themes.xml"))
                        Dim serializer As New XmlSerializer(GetType(ThemesModel))
                        _current = DirectCast(serializer.Deserialize(stream), ThemesModel)
                    End Using
                End If
                Return _current
            End SyncLock
        End Get
    End Property
    Private _groups As New List(Of ThemeGroupModel)()
    Public Shared ReadOnly Property MobileThemes() As IEnumerable(Of String)
        Get
            Return Current.Groups.First(Function(g) g.Name = "Mobile").Themes.Select(Function(t) t.Name)
        End Get
    End Property
    Public Shared ReadOnly Property AllThemes() As IEnumerable(Of ThemeModel)
        Get
            Return Current.Groups.SelectMany(Function(g) g.Themes)
        End Get
    End Property
    Public Shared ReadOnly Property NewThemes() As IEnumerable(Of ThemeModel)
        Get
            Return AllThemes.Where(Function(theme) theme.IsNew)
        End Get
    End Property
    Public Function GetAllGroups() As List(Of ThemeGroupModel)
        Dim topThemes = AllThemes.Where(Function(t) t.ShowAsTop).ToList()
        Dim currentTheme = AllThemes.First(Function(t) t.Name = Utils.CurrentTheme)
        If Not topThemes.Contains(currentTheme) Then
            topThemes.Add(currentTheme)
        End If
        Dim firstGroup = New ThemeGroupModel() With { _
            .Name = "FirstGroup", _
            .Themes = topThemes _
        }
        Return Groups.Concat( { firstGroup }).ToList()
    End Function
    <XmlElement("ThemeGroup")> _
    Public ReadOnly Property Groups() As List(Of ThemeGroupModel)
        Get
            Return _groups
        End Get
    End Property
    Public ReadOnly Property LeftGroups() As List(Of ThemeGroupModel)
        Get
            Return ( _
                From g In Groups _
                Where g.Float = "Left" _
                Select g).ToList()
        End Get
    End Property
    Public ReadOnly Property RightGroups() As List(Of ThemeGroupModel)
        Get
            Return ( _
                From g In Groups _
                Where g.Float = "Right" _
                Select g).ToList()
        End Get
    End Property
    Public Shared Function GetThemeModel(ByVal themeName As String) As ThemeModel
        Return Current.Groups.SelectMany(Function(g) g.Themes).FirstOrDefault(Function(t) t.Name = themeName)
    End Function
End Class

C#
using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.Configuration;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using DevExpress.Web.Internal;
using System.Drawing;
using DevExpress.Web;

public static class Utils {

    internal const string
        CurrentThemeCookieKeyPrefix = "DXCurrentTheme",
        CurrentBaseColorCookieKeyPrefix = "DXCurrentBaseColor",
        TunableThemeCookieKeyPrefix = "DXTunableTheme",
        CurrentFontCookieKey = "DXCurrentFont",
        DefaultThemeName = "Metropolis";

    public static string TunableThemeCookieKey {
        get {
            return TunableThemeCookieKeyPrefix;
        }
    }
    public static string DefaultTheme {
        get {
            return DefaultThemeName;
        }
    }
    public static List<ListEditItem> GetFontFamiliesDataSource() {
        return CustomFonts.Select(f => new ListEditItem() { Text = GetShortFontName(f), Value = f }).ToList();
    }
    public static string GetDefaultBaseColor(string themeName) {
        return ThemesModel.GetThemeModel(themeName).BaseColor;
    }

    public static string CurrentBaseColorCookieKey {
        get {
            return CurrentBaseColorCookieKeyPrefix;
        }
    }

    static HttpContext Context {
        get {
            return HttpContext.Current;
        }
    }
    public static string[] CustomBaseColors {
        get {
            return new string[] {
                    GetOrReplaceCurrentThemeDefaultBaseColor(),
                    "#4796CE",
                    "#35B86B",
                    "#CE5B47",
                    "#F7A233",
                    "#9F47CE",
                    "#5C57C9",
                    "#CE4776",
                };
        }
    }
    static Dictionary<string, string> ThemeBases = new Dictionary<string, string>() {
            { "MaterialCompact", "Material" }
        };
    public static bool CanChangeTheme {
        get {
            return true; ;
        }
    }
    static HttpRequest Request {
        get {
            return Context.Request;
        }
    }
    public static string CurrentThemeCookieKey {
        get {
            return CurrentThemeCookieKeyPrefix;
        }
    }
    public static string CurrentTheme {
        get {
            if(CanChangeTheme && Request.Cookies[CurrentThemeCookieKey] != null)
                return HttpUtility.UrlDecode(Request.Cookies[CurrentThemeCookieKey].Value);
            return DefaultTheme;
        }
    }
    public static string GetOrReplaceCurrentThemeDefaultBaseColor() {
        if(ThemeBases.ContainsKey(CurrentTheme)) {
            var themeModel = ThemesModel.GetThemeModel(ThemeBases[CurrentTheme]);
            return themeModel.BaseColor;
        }
        return CurrentThemeDefaultBaseColor;
    }
    static ThemeModel CurrentThemeModel {
        get { return ThemesModel.Current.Groups.SelectMany(g => g.Themes).FirstOrDefault(t => t.Name == CurrentTheme); }
    }
    public static string[] CustomFonts {
        get {
            return new string[] {
                    CurrentThemeDefaultFont,
                    CurrentThemeDefaultFontSize + " " + "'Asap', normal",
                    CurrentThemeDefaultFontSize + " " + "'Arima Madurai', normal",
                    CurrentThemeDefaultFontSize + " " + "'Comfortaa', normal"
                };
        }
    }
    public static string CurrentThemeDefaultFont { get { return CurrentThemeModel.Font; } }
    public static string CurrentThemeDefaultFontSize { get { return CurrentThemeModel.FontSize; } }
    public static string CurrentThemeDefaultBaseColor { get { return CurrentThemeModel.BaseColor; } }
    public static string CurrentFont {
        get {
            if(Request.Cookies[CurrentFontCookieKey] != null)
                return HttpUtility.UrlDecode(Request.Cookies[CurrentFontCookieKey].Value);
            return CurrentThemeDefaultFont;
        }
    }

    static bool IsThemeChanged {
        get {
            return CurrentTheme != TunableTheme;
        }
    }
    static string TunableTheme {
        get {
            if(Request.Cookies[TunableThemeCookieKey] != null)
                return HttpUtility.UrlDecode(Request.Cookies[TunableThemeCookieKey].Value);
            return CurrentTheme;
        }
        set {
            Context.Response.Cookies[TunableThemeCookieKey].Value = value;
        }
    }
    static void SetCurrentBaseColorCookie(string value) {
        if(string.IsNullOrWhiteSpace(value))
            Request.Cookies.Remove(CurrentBaseColorCookieKey);
        else
            Request.Cookies[CurrentBaseColorCookieKey].Value = value;
        Context.Response.Cookies[CurrentBaseColorCookieKey].Value = value;
    }
    static void SetCurrentFontCookie(string value) {
        Context.Response.Cookies[CurrentFontCookieKey].Value = value;
    }

    public static bool CanApplyThemeParameters {
        get {
            return (!string.IsNullOrEmpty(CurrentThemeDefaultFont) || !string.IsNullOrEmpty(CurrentThemeDefaultBaseColor));
        }
    }
    public static void ResolveThemeParametes() {
        if(!CanChangeTheme)
            return;
        string baseColor = CurrentBaseColor;
        string font = CurrentFont;
        if(IsThemeChanged || !string.IsNullOrEmpty(baseColor) && !CustomBaseColors.Contains(baseColor) || baseColor == CurrentThemeDefaultBaseColor) {
            baseColor = string.Empty;
            SetCurrentBaseColorCookie(baseColor);
        }
        if(IsThemeChanged || !string.IsNullOrEmpty(font) && !CustomFonts.Contains(font) || font == CurrentThemeDefaultFont) {
            font = string.Empty;
            SetCurrentFontCookie(font);
        }
        TunableTheme = CurrentTheme;
        ASPxWebControl.GlobalThemeBaseColor = baseColor;
        ASPxWebControl.GlobalThemeFont = font;
    }
    static string GetShortFontName(string fullName) {
        if(string.IsNullOrWhiteSpace(fullName))
            return fullName;
        int indexOfFirstSpace = fullName.IndexOf(' ');
        int indexOfFirstComma = fullName.IndexOf(',');
        int endPosition = indexOfFirstComma > -1 ? indexOfFirstComma - 1 : fullName.Length - 1;
        return fullName.Substring(indexOfFirstSpace + 1, endPosition - indexOfFirstSpace).Trim('\'');
    }
    public static bool CanChangeBaseColor {
        get {
            return ThemesModel.Current.Groups.Where(g => g.Themes.Where(t => t.Name == CurrentTheme && !String.IsNullOrEmpty(t.BaseColor)).Count() != 0).Count() > 0;
        }
    }
    public static string GetColoredSquareUrl(string color) {
        var svg = "<svg xmlns='http://www.w3.org/2000/svg'><g><rect height='100%' width='100%' y='0' x='0' fill='" +
            color + "'/></g></svg>";
        var svgEncoded = Convert.ToBase64String(Encoding.UTF8.GetBytes(svg));
        return "data:image/svg+xml;base64," + svgEncoded;
    }

    public static string CurrentBaseColor {
        get {
            if(Request.Cookies[CurrentBaseColorCookieKey] != null)
                return HttpUtility.UrlDecode(Request.Cookies[CurrentBaseColorCookieKey].Value);
            return CurrentThemeDefaultBaseColor;
        }
    }
    
}

Visual Basic
Option Infer On

Imports System
Imports System.Collections.Generic
Imports System.Configuration
Imports System.IO
Imports System.Linq
Imports System.Reflection
Imports System.Text
Imports System.Text.RegularExpressions
Imports System.Web
Imports System.Web.Configuration
Imports System.Web.UI
Imports System.Web.UI.HtmlControls
Imports System.Web.UI.WebControls
Imports DevExpress.Web.Internal
Imports System.Drawing
Imports DevExpress.Web

Public NotInheritable Class Utils

    Private Sub New()
    End Sub


    Friend Const CurrentThemeCookieKeyPrefix As String = "DXCurrentTheme", CurrentBaseColorCookieKeyPrefix As String = "DXCurrentBaseColor", TunableThemeCookieKeyPrefix As String = "DXTunableTheme", CurrentFontCookieKey As String = "DXCurrentFont", DefaultThemeName As String = "Metropolis"

    Public Shared ReadOnly Property TunableThemeCookieKey() As String
        Get
            Return TunableThemeCookieKeyPrefix
        End Get
    End Property
    Public Shared ReadOnly Property DefaultTheme() As String
        Get
            Return DefaultThemeName
        End Get
    End Property
    Public Shared Function GetFontFamiliesDataSource() As List(Of ListEditItem)
        Return CustomFonts.Select(Function(f) New ListEditItem() With { _
            .Text = GetShortFontName(f), _
            .Value = f _
        }).ToList()
    End Function
    Public Shared Function GetDefaultBaseColor(ByVal themeName As String) As String
        Return ThemesModel.GetThemeModel(themeName).BaseColor
    End Function

    Public Shared ReadOnly Property CurrentBaseColorCookieKey() As String
        Get
            Return CurrentBaseColorCookieKeyPrefix
        End Get
    End Property

    Private Shared ReadOnly Property Context() As HttpContext
        Get
            Return HttpContext.Current
        End Get
    End Property
    Public Shared ReadOnly Property CustomBaseColors() As String()
        Get
            Return New String() { GetOrReplaceCurrentThemeDefaultBaseColor(), "#4796CE", "#35B86B", "#CE5B47", "#F7A233", "#9F47CE", "#5C57C9", "#CE4776"}
        End Get
    End Property
    Private Shared ThemeBases As New Dictionary(Of String, String)() From { _
        { "MaterialCompact", "Material" } _
    }
    Public Shared ReadOnly Property CanChangeTheme() As Boolean
        Get
            Return True

        End Get
    End Property
    Private Shared ReadOnly Property Request() As HttpRequest
        Get
            Return Context.Request
        End Get
    End Property
    Public Shared ReadOnly Property CurrentThemeCookieKey() As String
        Get
            Return CurrentThemeCookieKeyPrefix
        End Get
    End Property
    Public Shared ReadOnly Property CurrentTheme() As String
        Get
            If CanChangeTheme AndAlso Request.Cookies(CurrentThemeCookieKey) IsNot Nothing Then
                Return HttpUtility.UrlDecode(Request.Cookies(CurrentThemeCookieKey).Value)
            End If
            Return DefaultTheme
        End Get
    End Property
    Public Shared Function GetOrReplaceCurrentThemeDefaultBaseColor() As String
        If ThemeBases.ContainsKey(CurrentTheme) Then
            Dim themeModel = ThemesModel.GetThemeModel(ThemeBases(CurrentTheme))
            Return themeModel.BaseColor
        End If
        Return CurrentThemeDefaultBaseColor
    End Function
    Private Shared ReadOnly Property CurrentThemeModel() As ThemeModel
        Get
            Return ThemesModel.Current.Groups.SelectMany(Function(g) g.Themes).FirstOrDefault(Function(t) t.Name = CurrentTheme)
        End Get
    End Property
    Public Shared ReadOnly Property CustomFonts() As String()
        Get
            Return New String() { CurrentThemeDefaultFont, CurrentThemeDefaultFontSize & " " & "'Asap', normal", CurrentThemeDefaultFontSize & " " & "'Arima Madurai', normal", CurrentThemeDefaultFontSize & " " & "'Comfortaa', normal" }
        End Get
    End Property
    Public Shared ReadOnly Property CurrentThemeDefaultFont() As String
        Get
            Return CurrentThemeModel.Font
        End Get
    End Property
    Public Shared ReadOnly Property CurrentThemeDefaultFontSize() As String
        Get
            Return CurrentThemeModel.FontSize
        End Get
    End Property
    Public Shared ReadOnly Property CurrentThemeDefaultBaseColor() As String
        Get
            Return CurrentThemeModel.BaseColor
        End Get
    End Property
    Public Shared ReadOnly Property CurrentFont() As String
        Get
            If Request.Cookies(CurrentFontCookieKey) IsNot Nothing Then
                Return HttpUtility.UrlDecode(Request.Cookies(CurrentFontCookieKey).Value)
            End If
            Return CurrentThemeDefaultFont
        End Get
    End Property

    Private Shared ReadOnly Property IsThemeChanged() As Boolean
        Get
            Return CurrentTheme <> TunableTheme
        End Get
    End Property
    Private Shared Property TunableTheme() As String
        Get
            If Request.Cookies(TunableThemeCookieKey) IsNot Nothing Then
                Return HttpUtility.UrlDecode(Request.Cookies(TunableThemeCookieKey).Value)
            End If
            Return CurrentTheme
        End Get
        Set(ByVal value As String)
            Context.Response.Cookies(TunableThemeCookieKey).Value = value
        End Set
    End Property
    Private Shared Sub SetCurrentBaseColorCookie(ByVal value As String)
        If String.IsNullOrWhiteSpace(value) Then
            Request.Cookies.Remove(CurrentBaseColorCookieKey)
        Else
            Request.Cookies(CurrentBaseColorCookieKey).Value = value
        End If
        Context.Response.Cookies(CurrentBaseColorCookieKey).Value = value
    End Sub
    Private Shared Sub SetCurrentFontCookie(ByVal value As String)
        Context.Response.Cookies(CurrentFontCookieKey).Value = value
    End Sub

    Public Shared ReadOnly Property CanApplyThemeParameters() As Boolean
        Get
            Return (Not String.IsNullOrEmpty(CurrentThemeDefaultFont) OrElse Not String.IsNullOrEmpty(CurrentThemeDefaultBaseColor))
        End Get
    End Property
    Public Shared Sub ResolveThemeParametes()
        If Not CanChangeTheme Then
            Return
        End If
        Dim baseColor As String = CurrentBaseColor
        Dim font As String = CurrentFont
        If IsThemeChanged OrElse Not String.IsNullOrEmpty(baseColor) AndAlso Not CustomBaseColors.Contains(baseColor) OrElse baseColor = CurrentThemeDefaultBaseColor Then
            baseColor = String.Empty
            SetCurrentBaseColorCookie(baseColor)
        End If
        If IsThemeChanged OrElse Not String.IsNullOrEmpty(font) AndAlso Not CustomFonts.Contains(font) OrElse font = CurrentThemeDefaultFont Then
            font = String.Empty
            SetCurrentFontCookie(font)
        End If
        TunableTheme = CurrentTheme
        ASPxWebControl.GlobalThemeBaseColor = baseColor
        ASPxWebControl.GlobalThemeFont = font
    End Sub
    Private Shared Function GetShortFontName(ByVal fullName As String) As String
        If String.IsNullOrWhiteSpace(fullName) Then
            Return fullName
        End If
        Dim indexOfFirstSpace As Integer = fullName.IndexOf(" "c)
        Dim indexOfFirstComma As Integer = fullName.IndexOf(","c)
        Dim endPosition As Integer = If(indexOfFirstComma > -1, indexOfFirstComma - 1, fullName.Length - 1)
        Return fullName.Substring(indexOfFirstSpace + 1, endPosition - indexOfFirstSpace).Trim("'"c)
    End Function
    Public Shared ReadOnly Property CanChangeBaseColor() As Boolean
        Get
            Return ThemesModel.Current.Groups.Where(Function(g) g.Themes.Where(Function(t) t.Name = CurrentTheme AndAlso Not String.IsNullOrEmpty(t.BaseColor)).Count() <> 0).Count() > 0
        End Get
    End Property
    Public Shared Function GetColoredSquareUrl(ByVal color As String) As String
        Dim svg = "<svg xmlns='http://www.w3.org/2000/svg'><g><rect height='100%' width='100%' y='0' x='0' fill='" & color & "'/></g></svg>"
        Dim svgEncoded = Convert.ToBase64String(Encoding.UTF8.GetBytes(svg))
        Return "data:image/svg+xml;base64," & svgEncoded
    End Function

    Public Shared ReadOnly Property CurrentBaseColor() As String
        Get
            If Request.Cookies(CurrentBaseColorCookieKey) IsNot Nothing Then
                Return HttpUtility.UrlDecode(Request.Cookies(CurrentBaseColorCookieKey).Value)
            End If
            Return CurrentThemeDefaultBaseColor
        End Get
    End Property

End Class

C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page {
    protected void Page_PreInit(object sender, EventArgs e) {

    }

    protected void Page_Load(object sender, EventArgs e) {

    }
}

Visual Basic
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls

Partial Public Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As EventArgs)

    End Sub

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    End Sub
End Class

C#
using DevExpress.Web.Internal;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class MasterPage : System.Web.UI.MasterPage {
 
}

Visual Basic
Imports DevExpress.Web.Internal
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls

Partial Public Class MasterPage
    Inherits System.Web.UI.MasterPage

End Class

C#
using DevExpress.Web;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class UserControl_ThemeParametersSelector : System.Web.UI.UserControl {
    protected void Page_Load(object sender, EventArgs e) {
        if(Utils.CanChangeBaseColor) {
            BaseColorEditor.DataSource = Utils.CustomBaseColors.Select(c => new { Value = c, ImageUrl = Utils.GetColoredSquareUrl(c) });
            BaseColorEditor.DataBind();
            string currentBaseColor = string.IsNullOrWhiteSpace(Utils.CurrentBaseColor) ? Utils.GetDefaultBaseColor(Utils.CurrentTheme) : Utils.CurrentBaseColor;
            var item = BaseColorEditor.Items.FindByValue(currentBaseColor);
            if(item != null)
                item.Selected = true;
        }
        FontEditor.DataSource = Utils.GetFontFamiliesDataSource().Select(i => new { Value = i.Value, Text = i.Text, ImageUrl = "" });
        FontEditor.DataBind();
        FontEditor.SelectedIndex = !string.IsNullOrEmpty(ASPxWebControl.GlobalThemeFont) ? FontEditor.Items.IndexOfValue(ASPxWebControl.GlobalThemeFont) : 0;
    }
    protected void Page_Init(object sender, EventArgs e) {
        InitEditor(BaseColorEditor);
        InitEditor(FontEditor);
    }
    protected void InitEditor(ASPxComboBox editor) {
        editor.DropDownStyle = DropDownStyle.DropDownList;
        editor.ValueField = "Value";
        editor.ImageUrlField = "ImageUrl";
        editor.ShowImageInEditBox = true;
        editor.CssClass += " themes-parameters-editor";
        editor.CaptionSettings.Position = EditorCaptionPosition.Top;
        editor.CaptionSettings.ShowColon = false;
        editor.CaptionStyle.CssClass = "themes-parameters-caption";
        editor.ListBoxStyle.CssClass += " themes-parameters-listbox";
        editor.ButtonStyle.CssClass = "themes-parameters-button-edit";
        editor.DropDownButton.Image.SpriteProperties.CssClass = "icon drop-down";
        editor.DropDownButton.Image.Height = 12;
        editor.DropDownButton.Image.Width = 12;
    }
}

Visual Basic
Option Infer On

Imports DevExpress.Web
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls

Partial Public Class UserControl_ThemeParametersSelector
    Inherits System.Web.UI.UserControl

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        If Utils.CanChangeBaseColor Then
            BaseColorEditor.DataSource = Utils.CustomBaseColors.Select(Function(c) New With { _
                Key .Value = c, _
                Key .ImageUrl = Utils.GetColoredSquareUrl(c) _
            })
            BaseColorEditor.DataBind()
            Dim currentBaseColor As String = If(String.IsNullOrWhiteSpace(Utils.CurrentBaseColor), Utils.GetDefaultBaseColor(Utils.CurrentTheme), Utils.CurrentBaseColor)
            Dim item = BaseColorEditor.Items.FindByValue(currentBaseColor)
            If item IsNot Nothing Then
                item.Selected = True
            End If
        End If
        FontEditor.DataSource = Utils.GetFontFamiliesDataSource().Select(Function(i) New With { _
            Key .Value = i.Value, _
            Key .Text = i.Text, _
            Key .ImageUrl = "" _
        })
        FontEditor.DataBind()
        FontEditor.SelectedIndex = If(Not String.IsNullOrEmpty(ASPxWebControl.GlobalThemeFont), FontEditor.Items.IndexOfValue(ASPxWebControl.GlobalThemeFont), 0)
    End Sub
    Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
        InitEditor(BaseColorEditor)
        InitEditor(FontEditor)
    End Sub
    Protected Sub InitEditor(ByVal editor As ASPxComboBox)
        editor.DropDownStyle = DropDownStyle.DropDownList
        editor.ValueField = "Value"
        editor.ImageUrlField = "ImageUrl"
        editor.ShowImageInEditBox = True
        editor.CssClass &= " themes-parameters-editor"
        editor.CaptionSettings.Position = EditorCaptionPosition.Top
        editor.CaptionSettings.ShowColon = False
        editor.CaptionStyle.CssClass = "themes-parameters-caption"
        editor.ListBoxStyle.CssClass &= " themes-parameters-listbox"
        editor.ButtonStyle.CssClass = "themes-parameters-button-edit"
        editor.DropDownButton.Image.SpriteProperties.CssClass = "icon drop-down"
        editor.DropDownButton.Image.Height = 12
        editor.DropDownButton.Image.Width = 12
    End Sub
End Class

C#
using DevExpress.Web;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Script.Serialization;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class UserControl_ThemeSelector : System.Web.UI.UserControl {
    protected void Page_Load(object sender, EventArgs e) {
        ThemesContainerRepeater.DataBind();
        ShowAllThemesButton.JSProperties["cpThemesListsNames"] = ThemesModel.Current.GetAllGroups().Select(g => GetThemesListClientName(g.Name)).ToList();
        ShowAllThemesButton.JSProperties["cpCurrenTheme"] = Utils.CurrentTheme;
    }
    protected void ThemesList_DataBinding(object sender, EventArgs e) {
        ASPxListBox themesList = (ASPxListBox)sender;
        RepeaterItem item = themesList.NamingContainer as RepeaterItem;
        if(item == null)
            return;
        ThemeGroupModel group = item.DataItem as ThemeGroupModel;
        BindThemesList(themesList, group);
    }
    void BindThemesList(ASPxListBox themesList, ThemeGroupModel group) {
        bool isFirstgroup = group.Name == "FirstGroup";
        themesList.Caption = group.Title;
        if(isFirstgroup)
            themesList.CssClass += " firstGroup";
        var dataSource = group.Themes.Select(t => new ListEditItem() {
            Value = GetThemeTitle(t.Name),
            Text = t.Title,
            ImageUrl = Utils.GetColoredSquareUrl(t.PreveiwColor),
        }).ToList();
        themesList.ClientInstanceName = GetThemesListClientName(group.Name);
        themesList.ClientVisible = isFirstgroup;
        themesList.Items.Clear();
        themesList.Items.AddRange(dataSource);
    }
    protected void ThemesLists_PreRender(object sender, EventArgs e) {
        ASPxListBox themesList = (ASPxListBox)sender;
        themesList.UnselectAll();
        var selectedItem = themesList.Items.FindByValue(GetThemeTitle(Utils.CurrentTheme));
        if(selectedItem != null)
            selectedItem.Selected = true;
        var jsSerializer = new JavaScriptSerializer();
        themesList.JSProperties["cpNewThemes"] = themesList.Items.Cast<ListEditItem>()
            .Where(item => ThemesModel.NewThemes.Select(t => t.Title).Contains(item.Text))
            .Select(item => item.Text);
    }
    string GetThemesListClientName(string groupName) {
        return "themesList" + groupName;
    }
    string GetThemeTitle(string themeName) {
        return !string.IsNullOrEmpty(themeName) ? themeName : "Default";
    }
}

Visual Basic
Option Infer On

Imports DevExpress.Web
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.Script.Serialization
Imports System.Web.UI
Imports System.Web.UI.WebControls

Partial Public Class UserControl_ThemeSelector
    Inherits System.Web.UI.UserControl

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        ThemesContainerRepeater.DataBind()
        ShowAllThemesButton.JSProperties("cpThemesListsNames") = ThemesModel.Current.GetAllGroups().Select(Function(g) GetThemesListClientName(g.Name)).ToList()
        ShowAllThemesButton.JSProperties("cpCurrenTheme") = Utils.CurrentTheme
    End Sub
    Protected Sub ThemesList_DataBinding(ByVal sender As Object, ByVal e As EventArgs)
        Dim themesList As ASPxListBox = DirectCast(sender, ASPxListBox)
        Dim item As RepeaterItem = TryCast(themesList.NamingContainer, RepeaterItem)
        If item Is Nothing Then
            Return
        End If
        Dim group As ThemeGroupModel = TryCast(item.DataItem, ThemeGroupModel)
        BindThemesList(themesList, group)
    End Sub
    Private Sub BindThemesList(ByVal themesList As ASPxListBox, ByVal group As ThemeGroupModel)
        Dim isFirstgroup As Boolean = group.Name = "FirstGroup"
        themesList.Caption = group.Title
        If isFirstgroup Then
            themesList.CssClass &= " firstGroup"
        End If
        Dim dataSource = group.Themes.Select(Function(t) New ListEditItem() With { _
            .Value = GetThemeTitle(t.Name), _
            .Text = t.Title, _
            .ImageUrl = Utils.GetColoredSquareUrl(t.PreveiwColor) _
        }).ToList()
        themesList.ClientInstanceName = GetThemesListClientName(group.Name)
        themesList.ClientVisible = isFirstgroup
        themesList.Items.Clear()
        themesList.Items.AddRange(dataSource)
    End Sub
    Protected Sub ThemesLists_PreRender(ByVal sender As Object, ByVal e As EventArgs)
        Dim themesList As ASPxListBox = DirectCast(sender, ASPxListBox)
        themesList.UnselectAll()
        Dim selectedItem = themesList.Items.FindByValue(GetThemeTitle(Utils.CurrentTheme))
        If selectedItem IsNot Nothing Then
            selectedItem.Selected = True
        End If
        Dim jsSerializer = New JavaScriptSerializer()
        themesList.JSProperties("cpNewThemes") = themesList.Items.Cast(Of ListEditItem)().Where(Function(item) ThemesModel.NewThemes.Select(Function(t) t.Title).Contains(item.Text)).Select(Function(item) item.Text)
    End Sub
    Private Function GetThemesListClientName(ByVal groupName As String) As String
        Return "themesList" & groupName
    End Function
    Private Function GetThemeTitle(ByVal themeName As String) As String
        Return If(Not String.IsNullOrEmpty(themeName), themeName, "Default")
    End Function
End Class