stgsharp/StgSharp.Common/MVVM/ViewModel/DataBinding.cs

//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="DataBinding"
// Project: StgSharp
// AuthorGroup: Nitload
// Copyright (c) Nitload. All rights reserved.
//     
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//     
// -----------------------------------------------------------------------
// -----------------------------------------------------------------------
using StgSharp.HighPerformance;

using System;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;

namespace StgSharp.MVVM.ViewModel
{
#nullable enable

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate ref object BindingDataGetter();
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate void BindingDataSetter(ref object value);
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate bool MethodLookUpDelegate(string name, out Action callback);

    public abstract partial class ViewModelBase
    {

        public bool MethodLookup(string methodName, out Action callback)
        {
            MethodInfo method = GetType().GetMethod(methodName)!;
            if (method == null)
            {
                callback = null!;
                return false;
            }
            try
            {
                callback = (Action)Delegate.CreateDelegate(typeof(Action), this, methodName);
                return true;
            }
            catch (MissingMethodException)
            {
                callback = null!;
                return false;
            }
            catch (MethodAccessException)
            {
                callback = null!;
                return false;
            }
            catch (Exception)
            {
                throw;
            }
        }

    }

    [StructLayout(LayoutKind.Explicit)]
    public unsafe struct DataBindingEntry
    {

        [FieldOffset(0)] private IntPtr getterPtr;
        [FieldOffset(8)] private IntPtr setterPtr;
        [FieldOffset(0)] private M128 _mask;

        public DataBindingEntry(
               [NotNull] BindingDataGetter gettingCallback,
               [NotNull] BindingDataSetter settingCallback)
        {
            getterPtr = Marshal.GetFunctionPointerForDelegate(gettingCallback);
            setterPtr = Marshal.GetFunctionPointerForDelegate(settingCallback);
        }

        public static DataBindingEntry NullBinding
        {
            get => new DataBindingEntry();
        }

        public bool Equals(DataBindingEntry other)
        {
            return (_mask == other._mask);
        }

        public override bool Equals(object obj)
        {
            if (obj is not DataBindingEntry other) {
                return false;
            }
            return Equals(other);
        }

        public bool ExactEqual(DataBindingEntry other)
        {
            return (getterPtr == other.getterPtr) && (setterPtr == other.setterPtr);
        }

        public override int GetHashCode()
        {
            return _mask.GetHashCode();
        }

        public ref object GetValue()
        {
            return ref ((delegate* unmanaged[Cdecl]<ref object>)getterPtr)();
        }

        public void SetValue(ref object value)
        {
            ((delegate* unmanaged[Cdecl]<ref object, void>)setterPtr)(ref value);
        }

        public static bool operator !=(DataBindingEntry left, DataBindingEntry right)
        {
            return left._mask != right._mask;
        }

        public static bool operator ==(DataBindingEntry left, DataBindingEntry right)
        {
            return left._mask == right._mask;
        }

    }

#nullable restore
}