Some C#/Xamarin wrappers for watchOS textProviderWithFormatformat

gistfile1.txt

using System;
using CoreGraphics;
using WatchKit;

namespace Common
{
    public static class WatchUtil
    {
        public static CGSize Watch_Size_Points
        {
            get { return WKInterfaceDevice.CurrentDevice.ScreenBounds.Size; }
        }

        public static CGSize Watch_Size_Pixels
        {
            get
            {
                nfloat scale = WKInterfaceDevice.CurrentDevice.ScreenScale;
                return new CGSize(Watch_Size_Points.Width * scale, Watch_Size_Points.Height * scale);
            }
        }

        public static bool Has_Rounded_Corners => Watch_Size == WatchSize.Size40 || Watch_Size == WatchSize.Size44;

        public static WatchSize Watch_Size
        {
            get
            {
                switch ((int)Watch_Size_Points.Width)
                {
                    // 38mm 136x170
                    case 136:
                        return WatchSize.Size38;

                    // 40mm 162x197
                    case 162:
                        return WatchSize.Size40;

                    // 42mm 156x195
                    case 156:
                        return WatchSize.Size42;

                    // 44mm 184x224
                    case 184:
                        return WatchSize.Size44;

                    default:
                        throw new NotImplementedException();
                }
            }
        }
    }
}

TextProviderWithFormat

using System;
using System.Runtime.InteropServices;
using ClockKit;
using Common;
using Foundation;
using ObjCRuntime;

namespace WatchExtension
{
    /// <summary>
    /// Provides wrappers to create a CLKTextProvider using watchOS textProviderWithFormatformat, ...)
    /// varargs function.
    /// </summary>
    /// <remarks>
    /// Help from Rolf Bjarne Kvinge and Manuel de la Pena.
    /// See:
    /// https://developer.apple.com/documentation/clockkit/clktextprovider/1627899-textproviderwithformat
    /// https://github.com/xamarin/xamarin-macios/issues/4864#issuecomment-426331883
    /// https://github.com/xamarin/xamarin-macios/blob/788b63d96f90ed173895d31be439ec23c67722a6/src/UIKit/UIAppearance.cs#L114-L118
    /// https://bugzilla.xamarin.com/show_bug.cgi?id=53271
    /// </remarks>
    public static class TextProviderWithFormat
    {
        [DllImport("/usr/lib/libobjc.dylib")]
        static extern IntPtr objc_msgSend(IntPtr obj, IntPtr selector, IntPtr format, IntPtr provider0);

        [DllImport("/usr/lib/libobjc.dylib")]
        static extern IntPtr objc_msgSend(IntPtr obj, IntPtr selector, IntPtr format, IntPtr provider0, IntPtr provider1);

        [DllImport("/usr/lib/libobjc.dylib")]
        static extern IntPtr objc_msgSend(IntPtr handle, IntPtr selector, IntPtr format, IntPtr dummy1, IntPtr dummy2, IntPtr dummy3, System.IntPtr dummy4, System.IntPtr dummy5, IntPtr provider0);

        [DllImport("/usr/lib/libobjc.dylib")]
        static extern IntPtr objc_msgSend(IntPtr handle, IntPtr selector, IntPtr format, IntPtr dummy1, IntPtr dummy2, IntPtr dummy3, System.IntPtr dummy4, System.IntPtr dummy5, IntPtr provider0, IntPtr provider1);

        // True for Series 4+ running on device
        public static bool Use_Dummy_Interop => WatchUtil.Has_Rounded_Corners && Runtime.Arch == Arch.DEVICE;

        public static CLKTextProvider Create(string format,
            CLKRelativeDateTextProvider provider)
        {
            IntPtr ptr;
            if (Use_Dummy_Interop)
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                                          Selector.GetHandle("textProviderWithFormat:"),
                                          new NSString(format).Handle,
                                          IntPtr.Zero, // dummy1
                                          IntPtr.Zero, // dummy2
                                          IntPtr.Zero, // dummy3
                                          IntPtr.Zero, // dummy4
                                          IntPtr.Zero, // dummy5
                                          provider.Handle);
            }
            else
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                          Selector.GetHandle("textProviderWithFormat:"),
                          new NSString(format).Handle, provider.Handle);
            }
            return Runtime.GetNSObject<CLKTextProvider>(ptr);
        }

        public static CLKTextProvider Create(string format,
            CLKTimeTextProvider timeTextProvider)
        {
            IntPtr ptr;
            if (Use_Dummy_Interop)
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                                          Selector.GetHandle("textProviderWithFormat:"),
                                          new NSString(format).Handle,
                                          IntPtr.Zero, // dummy1
                                          IntPtr.Zero, // dummy2
                                          IntPtr.Zero, // dummy3
                                          IntPtr.Zero, // dummy4
                                          IntPtr.Zero, // dummy5
                                          timeTextProvider.Handle);
            }
            else
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                                          Selector.GetHandle("textProviderWithFormat:"),
                                          new NSString(format).Handle,
                                          timeTextProvider.Handle);
            }
            return Runtime.GetNSObject<CLKTextProvider>(ptr);
        }

        public static CLKTextProvider Create(string format,
            CLKTextProvider textProvider,
            CLKRelativeDateTextProvider relativeDateTextProvider)
        {
            IntPtr ptr;
            if (Use_Dummy_Interop)
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                                          Selector.GetHandle("textProviderWithFormat:"),
                                          new NSString(format).Handle,
                                          textProvider.Handle,
                                          IntPtr.Zero, // dummy1
                                          IntPtr.Zero, // dummy2
                                          IntPtr.Zero, // dummy3
                                          IntPtr.Zero, // dummy4
                                          IntPtr.Zero, // dummy5
                                          relativeDateTextProvider.Handle);
            }
            else
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                                          Selector.GetHandle("textProviderWithFormat:"),
                                          new NSString(format).Handle,
                                          textProvider.Handle,
                                          relativeDateTextProvider.Handle);
            }
            return Runtime.GetNSObject<CLKTextProvider>(ptr);
        }

        public static CLKTextProvider Create(string format,
            CLKRelativeDateTextProvider relativeDateTextProvider,
                                             CLKTimeTextProvider timeTextProvider)
        {
            IntPtr ptr;
            if (Use_Dummy_Interop)
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                                          Selector.GetHandle("textProviderWithFormat:"),
                                          new NSString(format).Handle,
                                          IntPtr.Zero, // dummy1
                                          IntPtr.Zero, // dummy2
                                          IntPtr.Zero, // dummy3
                                          IntPtr.Zero, // dummy4
                                          IntPtr.Zero, // dummy5
                                          relativeDateTextProvider.Handle,
                                          timeTextProvider.Handle);
            }
            else
            {
                ptr = objc_msgSend(new Class(typeof(CLKTextProvider)).Handle,
                                          Selector.GetHandle("textProviderWithFormat:"),
                                          new NSString(format).Handle,
                                          relativeDateTextProvider.Handle,
                                          timeTextProvider.Handle);
            }
            return Runtime.GetNSObject<CLKTextProvider>(ptr);
        }
    }
}