ChoiceConverter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / MIT / System / Web / UI / MobileControls / Design / Converters / ChoiceConverter.cs / 1305376 / ChoiceConverter.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.UI.Design.MobileControls.Converters 
{ 
    using System.Diagnostics;
    using System.Collections; 
    using System.ComponentModel;
    using System.ComponentModel.Design;
    using System.Globalization;
    using System.Reflection; 
    using System.Web.UI.Design.MobileControls.Util;
    using System.Web.UI.MobileControls; 
    using System.Windows.Forms; 

    ///  
    ///    
    ///       Can filter and retrieve several types of values from controls.
    ///    
    ///  
    [
        System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand, 
        Flags=System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode) 
    ]
    [Obsolete("The System.Web.Mobile.dll assembly has been deprecated and should no longer be used. For information about how to develop ASP.NET mobile applications, see http://go.microsoft.com/fwlink/?LinkId=157231.")] 
    internal class ChoiceConverter: StringConverter
    {
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        { 
            if (context != null && context.Instance is Array)
            { 
                return value; 
            }
 
            if (value is String)
            {
                return MatchFilterName((string)value, context);
            } 

            return base.ConvertFrom(context, culture, value); 
        } 

        ///  
        /// 
        protected virtual Object [] GetChoices(Object instance)
        {
            bool defaultAdded = false; 
            DeviceSpecific deviceSpecific;
 
            if (instance is System.Web.UI.MobileControls.StyleSheet) 
            {
                StyleSheet ss = (StyleSheet) instance; 
                ISite componentSite = ss.Site;
                Debug.Assert(componentSite != null, "Expected the component to be sited.");
                IDesignerHost designerHost = (IDesignerHost) componentSite.GetService(typeof(IDesignerHost));
                Debug.Assert(designerHost != null, "Expected a designer host."); 
                Object designer = designerHost.GetDesigner(ss);
                Debug.Assert(designer != null, "Expected a designer for the stylesheet."); 
                Debug.Assert(designer is StyleSheetDesigner, "Expected a StyleSheet designer."); 
                StyleSheetDesigner ssd = (StyleSheetDesigner) designer;
                Style style = (Style) ssd.CurrentStyle; 
                if (null != style)
                {
                    deviceSpecific = style.DeviceSpecific;
                } 
                else
                { 
                    deviceSpecific = null; 
                }
            } 
            else if (instance is System.Web.UI.MobileControls.DeviceSpecific)
            {
                deviceSpecific = (DeviceSpecific) instance;
            } 
            else if (instance is MobileControl)
            { 
                MobileControl mc = (MobileControl) instance; 
                deviceSpecific = mc.DeviceSpecific;
            } 
            else
            {
                // Simply return null if the instance is not recognizable.
                return null; 
            }
 
            ArrayList returnArray = new ArrayList(); 

            // entry that corresponds to null CurrentChoice. 
            returnArray.Add(SR.GetString(SR.DeviceFilter_NoChoice));

            if (null == deviceSpecific)
            { 
                return returnArray.ToArray();
            } 
 
            Debug.Assert(deviceSpecific.Choices != null);
            foreach(DeviceSpecificChoice choice in deviceSpecific.Choices) 
            {
                // Choice must have a Name
                if (choice.Filter != null && choice.Filter.Length == 0)
                { 
                    if (!defaultAdded)
                    { 
                        returnArray.Add(SR.GetString(SR.DeviceFilter_DefaultChoice)); 
                        defaultAdded = true;
                    } 
                }
                else
                {
                    if (!choice.Filter.Equals(SR.GetString(SR.DeviceFilter_NoChoice))) 
                    {
                        returnArray.Add(DesignerUtility.ChoiceToUniqueIdentifier(choice)); 
                    } 
                }
            } 
            returnArray.Sort();
            return returnArray.ToArray();
        }
 
        /// 
        ///     
        ///       Returns a collection of standard values retrieved from the context specified 
        ///       by the specified type descriptor.
        ///     
        /// 
        /// 
        ///    A type descriptor that specifies the location of the context to convert from.
        ///  
        /// 
        ///     
        ///       A StandardValuesCollection that represents the standard values collected from 
        ///       the specified context.
        ///     
        /// 
        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
        {
            if (context == null || context.Instance == null) 
            {
                return null; 
            } 

            Object [] objValues = GetChoices(context.Instance); 
            if (objValues != null)
            {
                return new StandardValuesCollection(objValues);
            } 
            else
            { 
                return null; 
            }
        } 

        /// 
        ///    
        ///       Gets whether 
        ///       or not the context specified contains exclusive standard values.
        ///     
        ///  
        /// 
        ///    A type descriptor that indicates the context to convert from. 
        /// 
        /// 
        ///    
        ///     if the specified context contains exclusive standard 
        ///       values, otherwise .
        ///     
        ///  
        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
        { 
            return false;
        }

        ///  
        ///    
        ///       Gets whether or not the specified context contains supported standard 
        ///       values. 
        ///    
        ///  
        /// 
        ///    A type descriptor that indicates the context to convert from.
        /// 
        ///  
        ///    
        ///     if the specified context conatins supported standard 
        ///       values, otherwise . 
        ///    
        ///  
        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
        {
            return true;
        } 

        private String MatchFilterName(String name, ITypeDescriptorContext context) 
        { 
            Debug.Assert(name != null, "Expected an actual device filter name to match.");
 
            // Try a partial match
            //
            String bestMatch = null;
 
            StandardValuesCollection standardValues = GetStandardValues(context);
            if (standardValues == null) 
            { 
                return null;
            } 

            IEnumerator e = standardValues.GetEnumerator();
            while (e.MoveNext())
            { 
                string filterName = e.Current.ToString();
                if (String.Equals(filterName, name, StringComparison.OrdinalIgnoreCase)) { 
                    // For an exact match, return immediately 
                    //
                    return filterName; 
                }
                else if (e.Current.ToString().StartsWith(name, StringComparison.OrdinalIgnoreCase))
                {
                    if (bestMatch == null || filterName.Length <= bestMatch.Length) 
                    {
                        bestMatch = filterName; 
                    } 
                }
            } 

            if (bestMatch == null)
            {
                // no match... use NoChoice 
                bestMatch = SR.GetString(SR.DeviceFilter_NoChoice);
            } 
            return bestMatch; 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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ChoiceConverter.cs source code in C# .NET

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