feat: add support for URI activations for coder scheme (#72)

relates to #52

Adds support for Coder Desktop to handle the `coder:/` URI scheme by registering for this scheme and forwarding activations to the single instance of Coder Desktop.

Also removes the `Package.appxmanifest`. It is unused since Coder Desktop is not a packaged app.

Author: spikecurtis

App/App.xaml.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Diagnostics;
+using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 using Coder.Desktop.App.Models;
@@ -13,6 +14,8 @@
 using Microsoft.Extensions.Hosting;
 using Microsoft.UI.Xaml;
 using Microsoft.Win32;
+using Microsoft.Windows.AppLifecycle;
+using Windows.ApplicationModel.Activation;
 
 namespace Coder.Desktop.App;
 
@@ -82,7 +85,7 @@ public async Task ExitApplication()
         Environment.Exit(0);
     }
 
-    protected override void OnLaunched(LaunchActivatedEventArgs args)
+    protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
     {
         // Start connecting to the manager in the background.
         var rpcController = _services.GetRequiredService<IRpcController>();
@@ -138,4 +141,24 @@ protected override void OnLaunched(LaunchActivatedEventArgs args)
             trayWindow.AppWindow.Hide();
         };
     }
+
+    public void OnActivated(object? sender, AppActivationArguments args)
+    {
+        switch (args.Kind)
+        {
+            case ExtendedActivationKind.Protocol:
+                var protoArgs = args.Data as IProtocolActivatedEventArgs;
+                HandleURIActivation(protoArgs.Uri);
+                break;
+
+            default:
+                // TODO: log
+                break;
+        }
+    }
+
+    public void HandleURIActivation(Uri uri)
+    {
+        // TODO: handle
+    }
 }

App/Package.appxmanifest

@@ -1,4 +1,5 @@
 using System;
+using System.Reflection;
 using System.Runtime.InteropServices;
 using System.Threading;
 using Microsoft.UI.Dispatching;
@@ -26,7 +27,23 @@ private static void Main(string[] args)
         try
         {
             ComWrappersSupport.InitializeComWrappers();
-            if (!CheckSingleInstance()) return;
+            AppInstance mainInstance = GetMainInstance();
+            if (!mainInstance.IsCurrent)
+            {
+                var activationArgs = AppInstance.GetCurrent().GetActivatedEventArgs();
+                mainInstance.RedirectActivationToAsync(activationArgs).AsTask().Wait();
+                return;
+            }
+
+            // Register for URI handling (known as "protocol activation")
+#if DEBUG
+            const string scheme = "coder-debug";
+#else
+            const string scheme = "coder";
+#endif
+            var thisBin = Assembly.GetExecutingAssembly().Location;
+            ActivationRegistrationManager.RegisterForProtocolActivation(scheme, thisBin + ",1", "Coder Desktop", "");
+
             Application.Start(p =>
             {
                 var context = new DispatcherQueueSynchronizationContext(DispatcherQueue.GetForCurrentThread());
@@ -38,6 +55,9 @@ private static void Main(string[] args)
                     e.Handled = true;
                     ShowExceptionAndCrash(e.Exception);
                 };
+
+                // redirections via RedirectActivationToAsync above get routed to the App
+                mainInstance.Activated += app.OnActivated;
             });
         }
         catch (Exception e)
@@ -46,20 +66,17 @@ private static void Main(string[] args)
         }
     }
 
-    [STAThread]
-    private static bool CheckSingleInstance()
+    private static AppInstance GetMainInstance()
     {
 #if !DEBUG
         const string appInstanceName = "Coder.Desktop.App";
 #else
         const string appInstanceName = "Coder.Desktop.App.Debug";
 #endif
 
-        var instance = AppInstance.FindOrRegisterForKey(appInstanceName);
-        return instance.IsCurrent;
+        return AppInstance.FindOrRegisterForKey(appInstanceName);
     }
 
-    [STAThread]
     private static void ShowExceptionAndCrash(Exception e)
     {
         const string title = "Coder Desktop Fatal Error";