Add iOS/Catalyst support to Microsoft.Maui.PlatformChannels

Microsoft.Maui.PlatformChannels/Microsoft.Maui.PlatformChannels.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
 	<PropertyGroup>
-		<TargetFrameworks>net6.0-android</TargetFrameworks>
+		<TargetFrameworks>net6.0-android;net6.0-ios;net6.0-maccatalyst</TargetFrameworks>
 		<UseMaui>true</UseMaui>
 		<SingleProject>true</SingleProject>
 		<ImplicitUsings>enable</ImplicitUsings>
@@ -16,6 +16,12 @@
 	</ItemGroup>
 	<ItemGroup>
 		<ProjectReference Include="..\Microsoft.PlatformChannels\Microsoft.PlatformChannels.csproj" />
+	</ItemGroup>
+	<ItemGroup Condition="$(TargetFramework.Contains('-android'))">
 		<ProjectReference Include="..\Microsoft.PlatformChannels.Binding\Microsoft.PlatformChannels.Binding.csproj" />
 	</ItemGroup>
+	<ItemGroup Condition="'$(TargetFramework)' == 'net6.0-ios' OR '$(TargetFramework)' == 'net6.0-maccatalyst'">
+		<ProjectReference Include="..\Platforms\Apple\Microsoft.PlatformChannels.Binding.Apple\Microsoft.PlatformChannels.Binding.Apple.csproj" />
+	</ItemGroup>
+
 </Project>

Microsoft.Maui.PlatformChannels/Platforms/MacCatalyst/GlobalUsings.ios.cs

@@ -0,0 +1,2 @@
+global using PlatformView = global::UIKit.UIView;
+global using PlatformObject = global::Foundation.NSObject;

Microsoft.Maui.PlatformChannels/Platforms/MacCatalyst/PlatformChannelViewHandler.cs

@@ -0,0 +1,121 @@
+using Microsoft.Maui.Handlers;
+using Microsoft.PlatformChannels;
+using Foundation;
+using UIKit;
+
+using iOSViewChannel = Microsoft.PlatformChannels.Platform.ViewChannel;
+
+namespace Microsoft.Maui.PlatformChannels;
+
+public partial class PlatformChannelViewHandler : ViewHandler<IPlatformChannelView, UIKit.UIView>
+{
+	iOSViewChannel platformViewChannel;
+	PlatformManagedHandler managedHandler;
+	UIView viewGroup;
+
+	protected string ChannelTypeId { get; private set; }
+	protected string ChannelInstanceId { get; private set; }
+
+	IChannelService channelService;
+
+	protected override UIKit.UIView CreatePlatformView()
+	{
+		if (viewGroup is null) {
+			viewGroup = new UIView(new CoreGraphics.CGRect(0, 0, 400, 100));
+		}
+		EnsureChannelCreated();
+		return viewGroup;
+	}
+
+	void EnsureChannelCreated()
+	{
+		if (string.IsNullOrEmpty(VirtualView?.ChannelTypeId))
+			return;
+
+		var instanceId = VirtualView?.ChannelInstanceId ?? ChannelService.DEFAULT_INSTANCE_ID;
+
+		// Is the new id the same as the old?
+		if (VirtualView?.ChannelTypeId == ChannelTypeId)
+		{
+			// Is the instance null on both (so both default and the same)
+			// or is the new instance Id not the same as the old
+			if (instanceId == ChannelInstanceId)
+				return; // No change to actual channel, return
+		}
+
+		channelService ??= MauiContext.Services.GetRequiredService<IChannelService>();
+
+		if (platformViewChannel is not null)
+		{
+			foreach (var subview in viewGroup.Subviews) {
+				subview.RemoveFromSuperview ();
+			}
+
+			if (viewGroup.Superview is not null)
+				viewGroup.RemoveFromSuperview ();
+
+			channelService.DisposeChannel(ChannelTypeId, ChannelInstanceId);
+			platformViewChannel = null;
+		}
+
+		ChannelTypeId = VirtualView.ChannelTypeId;
+		ChannelInstanceId = instanceId;
+
+		var channel = Microsoft.PlatformChannels.Platform.ChannelService.GetOrCreate(ChannelTypeId, ChannelInstanceId);
+
+		if (channel == null) {
+			throw new InvalidOperationException($"No registered ViewChannel found for: '{ChannelTypeId}', instance: '{ChannelInstanceId}'");
+		}
+
+		if (channel is not iOSViewChannel viewChannel)
+			throw new InvalidCastException($"Registered channel '{ChannelTypeId}' is not a 'ViewChannel' type for instance: '{ChannelInstanceId}");
+
+		platformViewChannel = viewChannel;
+
+		managedHandler = new PlatformManagedHandler((id, parameters) =>
+		{
+			return OnReceivedFromPlatform?.Invoke(id, parameters);
+		});
+
+		platformViewChannel.SetManagedHandler(managedHandler);
+
+		var platformView = platformViewChannel.GetPlatformView();
+		viewGroup.AddSubview (platformView);
+	}
+
+    public static void MapChannelTypeId(IPlatformViewHandler handler, IPlatformChannelView view)
+	{
+		if (handler is PlatformChannelViewHandler h)
+			h.EnsureChannelCreated();
+	}
+
+	public static void MapChannelInstanceId(IPlatformViewHandler handler, IPlatformChannelView view)
+	{
+		if (handler is PlatformChannelViewHandler h)
+			h.EnsureChannelCreated();
+	}
+
+    internal object SendToPlatformImpl(string messageId, object[] args)
+    {
+		var platformObjs = args.ToPlatformObjects();
+
+		var platformResp = platformViewChannel?.OnChannelMessage(messageId, platformObjs);
+
+		var result = platformResp.ToDotNetObject();
+
+		return result;
+    }
+
+	class PlatformManagedHandler : NSObject, Microsoft.PlatformChannels.Platform.IChannelMessageHandler
+	{
+		public PlatformManagedHandler(Func<string, object[], object> callback)
+		{
+			Callback = callback;
+		}
+
+		protected readonly Func<string, object[], object> Callback;
+
+		public PlatformObject OnChannelMessage(string id, PlatformObject[] parameters)
+			=> Callback?.Invoke(id, parameters.ToDotNetObjects()).ToPlatformObject();
+	}
+}

Microsoft.Maui.PlatformChannels/Platforms/iOS/GlobalUsings.ios.cs

@@ -0,0 +1 @@
+../MacCatalyst/GlobalUsings.ios.cs

Microsoft.Maui.PlatformChannels/Platforms/iOS/PlatformChannelViewHandler.cs

@@ -0,0 +1 @@
+../MacCatalyst/PlatformChannelViewHandler.cs