Steven Kirk
11 years ago
9 changed files with 171 additions and 65 deletions
@ -0,0 +1,83 @@ |
|||
// -----------------------------------------------------------------------
|
|||
// <copyright file="TypeUtilities.cs" company="Steven Kirk">
|
|||
// Copyright 2015 MIT Licence. See licence.md for more information.
|
|||
// </copyright>
|
|||
// -----------------------------------------------------------------------
|
|||
|
|||
namespace Perspex.Utilities |
|||
{ |
|||
using System; |
|||
using System.Collections.Generic; |
|||
using System.Linq; |
|||
using System.Reflection; |
|||
|
|||
/// <summary>
|
|||
/// Provides utilities for working with types at runtime.
|
|||
/// </summary>
|
|||
internal static class TypeUtilities |
|||
{ |
|||
private static readonly Dictionary<Type, List<Type>> Conversions = new Dictionary<Type, List<Type>>() { |
|||
{ typeof(decimal), new List<Type> { typeof(sbyte), typeof(byte), typeof(short), typeof(ushort), typeof(int), typeof(uint), typeof(long), typeof(ulong), typeof(char) } }, |
|||
{ typeof(double), new List<Type> { typeof(sbyte), typeof(byte), typeof(short), typeof(ushort), typeof(int), typeof(uint), typeof(long), typeof(ulong), typeof(char), typeof(float) } }, |
|||
{ typeof(float), new List<Type> { typeof(sbyte), typeof(byte), typeof(short), typeof(ushort), typeof(int), typeof(uint), typeof(long), typeof(ulong), typeof(char), typeof(float) } }, |
|||
{ typeof(ulong), new List<Type> { typeof(byte), typeof(ushort), typeof(uint), typeof(char) } }, |
|||
{ typeof(long), new List<Type> { typeof(sbyte), typeof(byte), typeof(short), typeof(ushort), typeof(int), typeof(uint), typeof(char) } }, |
|||
{ typeof(uint), new List<Type> { typeof(byte), typeof(ushort), typeof(char) } }, |
|||
{ typeof(int), new List<Type> { typeof(sbyte), typeof(byte), typeof(short), typeof(ushort), typeof(char) } }, |
|||
{ typeof(ushort), new List<Type> { typeof(byte), typeof(char) } }, |
|||
{ typeof(short), new List<Type> { typeof(byte) } } |
|||
}; |
|||
|
|||
/// <summary>
|
|||
/// Try to cast a value to a type, using implicit conversions if possible.
|
|||
/// </summary>
|
|||
/// <param name="to">The type to cast to.</param>
|
|||
/// <param name="value">The value to cast.</param>
|
|||
/// <param name="result">If sucessful, contains the cast value.</param>
|
|||
/// <returns>True if the cast was sucessful, otherwise false.</returns>
|
|||
public static bool TryCast(Type to, object value, out object result) |
|||
{ |
|||
Contract.Requires<NullReferenceException>(to != null); |
|||
|
|||
if (value == null) |
|||
{ |
|||
var t = to.GetTypeInfo(); |
|||
result = null; |
|||
return !t.IsValueType || (t.IsGenericType && (t.GetGenericTypeDefinition() == typeof(Nullable<>))); |
|||
} |
|||
|
|||
var from = value.GetType(); |
|||
|
|||
if (value == PerspexProperty.UnsetValue) |
|||
{ |
|||
result = value; |
|||
return true; |
|||
} |
|||
else if (to.GetTypeInfo().IsAssignableFrom(from.GetTypeInfo())) |
|||
{ |
|||
result = value; |
|||
return true; |
|||
} |
|||
else if (Conversions.ContainsKey(to) && Conversions[to].Contains(from)) |
|||
{ |
|||
result = Convert.ChangeType(value, to); |
|||
return true; |
|||
} |
|||
else |
|||
{ |
|||
var cast = from.GetTypeInfo() |
|||
.GetDeclaredMethods("op_Implicit") |
|||
.FirstOrDefault(m => m.ReturnType == to); |
|||
|
|||
if (cast != null) |
|||
{ |
|||
result = cast.Invoke(null, new[] { value }); |
|||
return true; |
|||
} |
|||
} |
|||
|
|||
result = null; |
|||
return false; |
|||
} |
|||
} |
|||
} |
|||
@ -0,0 +1,13 @@ |
|||
// This file is used by Code Analysis to maintain SuppressMessage
|
|||
// attributes that are applied to this project.
|
|||
// Project-level suppressions either have no target or are given
|
|||
// a specific target and scoped to a namespace, type, member, etc.
|
|||
|
|||
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage( |
|||
"StyleCop.CSharp.DocumentationRules", |
|||
"SA1600:Elements must be documented", |
|||
Justification = "Tests should be self-documenting")] |
|||
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage( |
|||
"StyleCop.CSharp.NamingRules", |
|||
"SA1300:Element must begin with upper-case letter", |
|||
Justification = "Some tests must begin with lower-case letters")] |
|||
Loading…
Reference in new issue