PointConverter.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / CommonUI / System / Drawing / PointConverter.cs / 1 / PointConverter.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/* 
 */ 
namespace System.Drawing {
    using System.Runtime.Serialization.Formatters; 
    using System.Runtime.InteropServices;

    using System.Diagnostics;
    using System.Diagnostics.CodeAnalysis; 

    using Microsoft.Win32; 
    using System.Collections; 
    using System.ComponentModel;
    using System.ComponentModel.Design.Serialization; 
    using System.Globalization;
    using System.Reflection;

    ///  
    /// 
    ///      PointConverter is a class that can be used to convert 
    ///      Point from one data type to another.  Access this 
    ///      class through the TypeDescriptor.
    ///  
    public class PointConverter : TypeConverter {

        /// 
        ///  
        ///      Determines if this converter can convert an object in the given source
        ///      type to the native type of the converter. 
        ///  
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
            if (sourceType == typeof(string)) { 
                return true;
            }
            return base.CanConvertFrom(context, sourceType);
        } 

        ///  
        ///  
        ///    Gets a value indicating whether this converter can
        ///       convert an object to the given destination type using the context. 
        /// 
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
            if (destinationType == typeof(InstanceDescriptor)) {
                return true; 
            }
            return base.CanConvertTo(context, destinationType); 
        } 

        ///  
        /// 
        ///      Converts the given object to the converter's native type.
        /// 
        [SuppressMessage("Microsoft.Performance", "CA1808:AvoidCallsThatBoxValueTypes")] 
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {
 
            string strValue = value as string; 

            if (strValue != null) { 

                string text = strValue.Trim();

                if (text.Length == 0) { 
                    return null;
                } 
                else { 

                    // Parse 2 integer values. 
                    //
                    if (culture == null) {
                        culture = CultureInfo.CurrentCulture;
                    } 
                    char sep = culture.TextInfo.ListSeparator[0];
                    string[] tokens = text.Split(new char[] {sep}); 
                    int[] values = new int[tokens.Length]; 
                    TypeConverter intConverter = TypeDescriptor.GetConverter(typeof(int));
                    for (int i = 0; i < values.Length; i++) { 
                        // Note: ConvertFromString will raise exception if value cannot be converted.
                        values[i] = (int)intConverter.ConvertFromString(context, culture, tokens[i]);
                    }
 
                    if (values.Length == 2) {
                        return new Point(values[0], values[1]); 
                    } 
                    else {
                        throw new ArgumentException(SR.GetString(SR.TextParseFailedFormat, 
                                                                  text,
                                                                  "x, y"));
                    }
                } 
            }
 
            return base.ConvertFrom(context, culture, value); 
        }
 
        /// 
        /// 
        ///      Converts the given object to another type.  The most common types to convert
        ///      are to and from a string object.  The default implementation will make a call 
        ///      to ToString on the object if the object is valid and if the destination
        ///      type is string.  If this cannot convert to the desitnation type, this will 
        ///      throw a NotSupportedException. 
        /// 
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) { 
            if (destinationType == null) {
                throw new ArgumentNullException("destinationType");
            }
 
            if(value is Point){
                if (destinationType == typeof(string)) { 
                    Point pt = (Point)value; 

                    if (culture == null) { 
                        culture = CultureInfo.CurrentCulture;
                    }
                    string sep = culture.TextInfo.ListSeparator + " ";
                    TypeConverter intConverter = TypeDescriptor.GetConverter(typeof(int)); 
                    string[] args = new string[2];
                    int nArg = 0; 
 
                    // Note: ConvertToString will raise exception if value cannot be converted.
                    args[nArg++] = intConverter.ConvertToString(context, culture, pt.X); 
                    args[nArg++] = intConverter.ConvertToString(context, culture, pt.Y);

                    return string.Join(sep, args);
                } 
                if (destinationType == typeof(InstanceDescriptor)) {
                    Point pt = (Point)value; 
 
                    ConstructorInfo ctor = typeof(Point).GetConstructor(new Type[] {typeof(int), typeof(int)});
                    if (ctor != null) { 
                        return new InstanceDescriptor(ctor, new object[] {pt.X, pt.Y});
                    }
                }
            } 

            return base.ConvertTo(context, culture, value, destinationType); 
        } 

        ///  
        /// 
        ///      Creates an instance of this type given a set of property values
        ///      for the object.  This is useful for objects that are immutable, but still
        ///      want to provide changable properties. 
        /// 
        [SuppressMessage("Microsoft.Performance", "CA1808:AvoidCallsThatBoxValueTypes")] 
        [SuppressMessage("Microsoft.Security", "CA2102:CatchNonClsCompliantExceptionsInGeneralHandlers")] 
        public override object CreateInstance(ITypeDescriptorContext context, IDictionary propertyValues) {
            if( propertyValues == null ) { 
                throw new ArgumentNullException( "propertyValues" );
            }

            object x = propertyValues["X"]; 
            object y = propertyValues["Y"];
 
            if(x == null || y == null || 
                !(x is int) || !(y is int)) {
                throw new ArgumentException(SR.GetString(SR.PropertyValueInvalidEntry)); 
            }


            return new Point((int)x, 
                              (int)y);
 
        } 

        ///  
        /// 
        ///      Determines if changing a value on this object should require a call to
        ///      CreateInstance to create a new value.
        ///  
        public override bool GetCreateInstanceSupported(ITypeDescriptorContext context) {
            return true; 
        } 

        ///  
        /// 
        ///      Retrieves the set of properties for this type.  By default, a type has
        ///      does not return any properties.  An easy implementation of this method
        ///      can just call TypeDescriptor.GetProperties for the correct data type. 
        /// 
        public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object value, Attribute[] attributes) { 
            PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(Point), attributes); 
            return props.Sort(new string[] {"X", "Y"});
        } 


        /// 
        ///  
        ///      Determines if this object supports properties.  By default, this
        ///      is false. 
        ///  
        public override bool GetPropertiesSupported(ITypeDescriptorContext context) {
            return true; 
        }

    }
} 

 
// File provided for Reference Use Only by Microsoft Corporation (c) 2007. 
// Copyright (c) Microsoft Corporation. All rights reserved.
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PointConverter.cs source code in C# .NET

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