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Diffstat (limited to 'src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs')
| -rw-r--r-- | src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs new file mode 100644 index 00000000..17758a39 --- /dev/null +++ b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs @@ -0,0 +1,197 @@ +using System; +using System.Reflection; +using StardewModdingAPI.Reflection; + +namespace StardewModdingAPI.Framework.Reflection +{ + /// <summary>Provides helper methods for accessing private game code.</summary> + internal class ReflectionHelper : IReflectionHelper + { + /********* + ** Public methods + *********/ + /**** + ** Fields + ****/ + /// <summary>Get a private instance field.</summary> + /// <typeparam name="TValue">The field type.</typeparam> + /// <param name="obj">The object which has the field.</param> + /// <param name="name">The field name.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + /// <returns>Returns the field wrapper, or <c>null</c> if the field doesn't exist and <paramref name="required"/> is <c>false</c>.</returns> + public IPrivateField<TValue> GetPrivateField<TValue>(object obj, string name, bool required = true) + { + // validate + if (obj == null) + throw new ArgumentNullException(nameof(obj), "Can't get a private instance field from a null object."); + + // get field from hierarchy + IPrivateField<TValue> field = this.GetFieldFromHierarchy<TValue>(obj.GetType(), obj, name, BindingFlags.Instance | BindingFlags.NonPublic); + if (required && field == null) + throw new InvalidOperationException($"The {obj.GetType().FullName} object doesn't have a private '{name}' instance field."); + return field; + } + + /// <summary>Get a private static field.</summary> + /// <typeparam name="TValue">The field type.</typeparam> + /// <param name="type">The type which has the field.</param> + /// <param name="name">The field name.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + public IPrivateField<TValue> GetPrivateField<TValue>(Type type, string name, bool required = true) + { + // get field from hierarchy + IPrivateField<TValue> field = this.GetFieldFromHierarchy<TValue>(type, null, name, BindingFlags.NonPublic | BindingFlags.Static); + if (required && field == null) + throw new InvalidOperationException($"The {type.FullName} object doesn't have a private '{name}' static field."); + return field; + } + + /**** + ** Field values + ** (shorthand since this is the most common case) + ****/ + /// <summary>Get the value of a private instance field.</summary> + /// <typeparam name="TValue">The field type.</typeparam> + /// <param name="obj">The object which has the field.</param> + /// <param name="name">The field name.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + /// <remarks>This is a shortcut for <see cref="GetPrivateField{TValue}(object,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.</remarks> + public TValue GetPrivateValue<TValue>(object obj, string name, bool required = true) + { + return this.GetPrivateField<TValue>(obj, name, required).GetValue(); + } + + /// <summary>Get the value of a private static field.</summary> + /// <typeparam name="TValue">The field type.</typeparam> + /// <param name="type">The type which has the field.</param> + /// <param name="name">The field name.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + /// <remarks>This is a shortcut for <see cref="GetPrivateField{TValue}(Type,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.</remarks> + public TValue GetPrivateValue<TValue>(Type type, string name, bool required = true) + { + return this.GetPrivateField<TValue>(type, name, required).GetValue(); + } + + /**** + ** Methods + ****/ + /// <summary>Get a private instance method.</summary> + /// <param name="obj">The object which has the method.</param> + /// <param name="name">The field name.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + public IPrivateMethod GetPrivateMethod(object obj, string name, bool required = true) + { + // validate + if (obj == null) + throw new ArgumentNullException(nameof(obj), "Can't get a private instance method from a null object."); + + // get method from hierarchy + IPrivateMethod method = this.GetMethodFromHierarchy(obj.GetType(), obj, name, BindingFlags.Instance | BindingFlags.NonPublic); + if (required && method == null) + throw new InvalidOperationException($"The {obj.GetType().FullName} object doesn't have a private '{name}' instance method."); + return method; + } + + /// <summary>Get a private static method.</summary> + /// <param name="type">The type which has the method.</param> + /// <param name="name">The field name.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + public IPrivateMethod GetPrivateMethod(Type type, string name, bool required = true) + { + // get method from hierarchy + IPrivateMethod method = this.GetMethodFromHierarchy(type, null, name, BindingFlags.NonPublic | BindingFlags.Static); + if (required && method == null) + throw new InvalidOperationException($"The {type.FullName} object doesn't have a private '{name}' static method."); + return method; + } + + /**** + ** Methods by signature + ****/ + /// <summary>Get a private instance method.</summary> + /// <param name="obj">The object which has the method.</param> + /// <param name="name">The field name.</param> + /// <param name="argumentTypes">The argument types of the method signature to find.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + public IPrivateMethod GetPrivateMethod(object obj, string name, Type[] argumentTypes, bool required = true) + { + // validate parent + if (obj == null) + throw new ArgumentNullException(nameof(obj), "Can't get a private instance method from a null object."); + + // get method from hierarchy + PrivateMethod method = this.GetMethodFromHierarchy(obj.GetType(), obj, name, BindingFlags.Instance | BindingFlags.NonPublic, argumentTypes); + if (required && method == null) + throw new InvalidOperationException($"The {obj.GetType().FullName} object doesn't have a private '{name}' instance method with that signature."); + return method; + } + + /// <summary>Get a private static method.</summary> + /// <param name="type">The type which has the method.</param> + /// <param name="name">The field name.</param> + /// <param name="argumentTypes">The argument types of the method signature to find.</param> + /// <param name="required">Whether to throw an exception if the private field is not found.</param> + public IPrivateMethod GetPrivateMethod(Type type, string name, Type[] argumentTypes, bool required = true) + { + // get field from hierarchy + PrivateMethod method = this.GetMethodFromHierarchy(type, null, name, BindingFlags.NonPublic | BindingFlags.Static, argumentTypes); + if (required && method == null) + throw new InvalidOperationException($"The {type.FullName} object doesn't have a private '{name}' static method with that signature."); + return method; + } + + + /********* + ** Private methods + *********/ + /// <summary>Get a field from the type hierarchy.</summary> + /// <typeparam name="TValue">The expected field type.</typeparam> + /// <param name="type">The type which has the field.</param> + /// <param name="obj">The object which has the field.</param> + /// <param name="name">The field name.</param> + /// <param name="bindingFlags">The reflection binding which flags which indicates what type of field to find.</param> + private IPrivateField<TValue> GetFieldFromHierarchy<TValue>(Type type, object obj, string name, BindingFlags bindingFlags) + { + FieldInfo field = null; + for (; type != null && field == null; type = type.BaseType) + field = type.GetField(name, bindingFlags); + + return field != null + ? new PrivateField<TValue>(type, obj, field, isStatic: bindingFlags.HasFlag(BindingFlags.Static)) + : null; + } + + /// <summary>Get a method from the type hierarchy.</summary> + /// <param name="type">The type which has the method.</param> + /// <param name="obj">The object which has the method.</param> + /// <param name="name">The method name.</param> + /// <param name="bindingFlags">The reflection binding which flags which indicates what type of method to find.</param> + private IPrivateMethod GetMethodFromHierarchy(Type type, object obj, string name, BindingFlags bindingFlags) + { + MethodInfo method = null; + for (; type != null && method == null; type = type.BaseType) + method = type.GetMethod(name, bindingFlags); + + return method != null + ? new PrivateMethod(type, obj, method, isStatic: bindingFlags.HasFlag(BindingFlags.Static)) + : null; + } + + /// <summary>Get a method from the type hierarchy.</summary> + /// <param name="type">The type which has the method.</param> + /// <param name="obj">The object which has the method.</param> + /// <param name="name">The method name.</param> + /// <param name="bindingFlags">The reflection binding which flags which indicates what type of method to find.</param> + /// <param name="argumentTypes">The argument types of the method signature to find.</param> + private PrivateMethod GetMethodFromHierarchy(Type type, object obj, string name, BindingFlags bindingFlags, Type[] argumentTypes) + { + MethodInfo method = null; + for (; type != null && method == null; type = type.BaseType) + method = type.GetMethod(name, bindingFlags, null, argumentTypes, null); + + return method != null + ? new PrivateMethod(type, obj, method, isStatic: bindingFlags.HasFlag(BindingFlags.Static)) + : null; + } + } +}
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