FontUnitConverter.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / xsp / System / Web / UI / WebControls / FontUnitConverter.cs / 1 / FontUnitConverter.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.UI.WebControls { 
 
    using System;
    using System.Collections; 
    using System.ComponentModel;
    using System.ComponentModel.Design.Serialization;
    using System.Globalization;
    using System.Reflection; 
    using System.Security.Permissions;
    using System.Web.Util; 
 

    ///  
    /// Converts a  to and from a specified data type.
    /// 
    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    public class FontUnitConverter : TypeConverter {
        private StandardValuesCollection values; 
 

        ///  
        /// Determines if the specified data type can be converted to a .
        /// 
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
            if (sourceType == typeof(string)) { 
                return true;
            } 
            else { 
                return base.CanConvertFrom(context, sourceType);
            } 
        }


        ///  
        /// Converts the specified  into a .
        ///  
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) { 
            if (value == null)
                return null; 

            string stringValue = value as string;
            if (stringValue != null) {
                string textValue = stringValue.Trim(); 
                if (textValue.Length == 0) {
                    return FontUnit.Empty; 
                } 
                return FontUnit.Parse(textValue, culture);
            } 
            else {
                return base.ConvertFrom(context, culture, value);
            }
        } 

 
        ///  
        /// 
        ///   Returns a value indicating whether the converter can 
        ///   convert to the specified destination type.
        /// 
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
            if ((destinationType == typeof(string)) || 
                (destinationType == typeof(InstanceDescriptor))) {
                return true; 
            } 
            else {
                return base.CanConvertTo(context, destinationType); 
            }
        }

 
        /// 
        /// Converts the specified  into the specified .  
        ///  
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
            if (destinationType == typeof(string)) { 
                if ((value == null) || (((FontUnit)value).Type == FontSize.NotSet))
                    return String.Empty;
                else
                    return ((FontUnit)value).ToString(culture); 
            }
            else if ((destinationType == typeof(InstanceDescriptor)) && (value != null)) { 
                FontUnit u = (FontUnit)value; 
                MemberInfo member = null;
                object[] args = null; 

                if (u.IsEmpty) {
                    member = typeof(FontUnit).GetField("Empty");
                } 
                else if (u.Type != FontSize.AsUnit) {
                    string fieldName = null; 
                    switch (u.Type) { 
                        case FontSize.Smaller:
                            fieldName = "Smaller"; 
                            break;
                        case FontSize.Larger:
                            fieldName = "Larger";
                            break; 
                        case FontSize.XXSmall:
                            fieldName = "XXSmall"; 
                            break; 
                        case FontSize.XSmall:
                            fieldName = "XSmall"; 
                            break;
                        case FontSize.Small:
                            fieldName = "Small";
                            break; 
                        case FontSize.Medium:
                            fieldName = "Medium"; 
                            break; 
                        case FontSize.Large:
                            fieldName = "Large"; 
                            break;
                        case FontSize.XLarge:
                            fieldName = "XLarge";
                            break; 
                        case FontSize.XXLarge:
                            fieldName = "XXLarge"; 
                            break; 
                    }
                    Debug.Assert(fieldName != null, "Invalid FontSize type"); 
                    if (fieldName != null) {
                        member = typeof(FontUnit).GetField(fieldName);
                    }
                } 
                else {
                    member = typeof(FontUnit).GetConstructor(new Type[] { typeof(Unit) }); 
                    args = new object[] { u.Unit }; 
                }
 
                Debug.Assert(member != null, "Looks like we're missing FontUnit static fields or FontUnit::ctor(Unit)");
                if (member != null) {
                    return new InstanceDescriptor(member, args);
                } 
                else {
                    return null; 
                } 
            }
            else { 
                return base.ConvertTo(context, culture, value, destinationType);
            }
        }
 

        ///  
        /// Returns a  
        /// containing standard  values.
        ///  
        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) {
            if (values == null) {
                object[] namedUnits = new object[] {
                    FontUnit.Smaller, 
                    FontUnit.Larger,
                    FontUnit.XXSmall, 
                    FontUnit.XSmall, 
                    FontUnit.Small,
                    FontUnit.Medium, 
                    FontUnit.Large,
                    FontUnit.XLarge,
                    FontUnit.XXLarge
                }; 

                values = new StandardValuesCollection(namedUnits); 
            } 
            return values;
        } 


        /// 
        ///    Indicates whether the specified context contains exclusive standard 
        ///       values.
        ///  
        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) { 
            return false;
        } 


        /// 
        ///    Indicates whether the specified context contains suppurted standard 
        ///       values.
        ///  
        public override bool GetStandardValuesSupported(ITypeDescriptorContext context) { 
            return true;
        } 
    }
}

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