Avalonia/src/iOS/Avalonia.iOS/Interop.cs

using System;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using CoreFoundation;
using Foundation;
using ObjCRuntime;

namespace Avalonia.iOS;

// TODO: use LibraryImport in NET7
internal class Interop
{
    internal const string CoreFoundationLibrary = "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation";
    internal static NativeHandle kCFRunLoopCommonModes = CFString.CreateNative("kCFRunLoopCommonModes");

    [Flags]
    internal enum CFOptionFlags : ulong
    {
        kCFRunLoopBeforeSources = (1UL << 2),
        kCFRunLoopAfterWaiting = (1UL << 6),
        kCFRunLoopBeforeWaiting = (1UL << 5)
    }

    [UnmanagedFunctionPointer(CallingConvention.StdCall)]
    internal delegate void CFRunLoopObserverCallback(IntPtr observer, CFOptionFlags activity, IntPtr info);

    [UnmanagedFunctionPointer(CallingConvention.StdCall)]
    internal delegate void CFRunLoopTimerCallback(IntPtr timer, IntPtr info);
    
    [DllImport(CoreFoundationLibrary)]
    internal static extern IntPtr CFRunLoopGetMain();

    [DllImport(CoreFoundationLibrary)]
    internal static extern IntPtr CFRunLoopObserverCreate(IntPtr allocator, CFOptionFlags activities,
        bool repeats, int index, CFRunLoopObserverCallback callout, IntPtr context);

    [DllImport(CoreFoundationLibrary)]
    internal static extern IntPtr CFRunLoopAddObserver(IntPtr loop, IntPtr observer, IntPtr mode);

    [DllImport(CoreFoundationLibrary)]
    internal static extern IntPtr CFRunLoopTimerCreate(IntPtr allocator, double firstDate, double interval,
        CFOptionFlags flags, int order, CFRunLoopTimerCallback callout, IntPtr context);

    [DllImport(CoreFoundationLibrary)]
    internal static extern void CFRunLoopTimerSetTolerance(IntPtr timer, double tolerance);

    [DllImport(CoreFoundationLibrary)]
    internal static extern void CFRunLoopTimerSetNextFireDate(IntPtr timer, double fireDate);

    [DllImport(CoreFoundationLibrary)]
    internal static extern void CFRunLoopAddTimer(IntPtr loop, IntPtr timer, IntPtr mode);

    [DllImport(CoreFoundationLibrary)]
    internal static extern double CFAbsoluteTimeGetCurrent();
}