Allow drag'n'drop of .gcdump on the main window and launching without…

… parameter

src/OneHub.Tools.HeapView/App.axaml.cs

@@ -1,7 +1,9 @@
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
+using Avalonia.Threading;
 using System;
+using System.IO;
 
 namespace OneHub.Tools.HeapView;
 
@@ -16,10 +18,14 @@ public override void OnFrameworkInitializationCompleted()
     {
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
-            if (desktop.Args?.Length > 0)
-                desktop.MainWindow = new MainWindow(desktop.Args[0]);
-            else
-                Environment.Exit(1);
+            var mainWindow = new MainWindow();
+            desktop.MainWindow = mainWindow;
+            switch (desktop.Args)
+            {
+                case [string fileName, ..] when File.Exists(fileName):
+                    mainWindow.Open(fileName);
+                    break;
+            }
         }
 
         base.OnFrameworkInitializationCompleted();

src/OneHub.Tools.HeapView/MainWindow.axaml

@@ -6,7 +6,8 @@
 		xmlns:heapView="using:OneHub.Diagnostics.HeapView"
         mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
         x:Class="OneHub.Tools.HeapView.MainWindow"
-        Title="Heap View">
+        Title="Heap View"
+		DragDrop.AllowDrop="True">
 	<heapView:HeapView Name="heapView">
 	</heapView:HeapView>
 </Window>

src/OneHub.Tools.HeapView/MainWindow.axaml.cs

@@ -1,19 +1,53 @@
 using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Platform.Storage;
 using OneHub.Diagnostics.HeapView;
+using System.Linq;
+using System;
 
 namespace OneHub.Tools.HeapView;
 
 public partial class MainWindow : Window
 {
-    HeapSnapshot heapSnapshot;
-
-    public MainWindow(string fileName)
+    public MainWindow()
     {
         InitializeComponent();
 
-        var heapDump = new GCHeapDump(fileName);
-        heapSnapshot = new HeapSnapshot(heapDump);
+        AddHandler(DragDrop.DragOverEvent, DragOver);
+        AddHandler(DragDrop.DropEvent, Drop);
+    }
+
+    public void Open(string fileName)
+    {
+        try
+        {
+            var heapDump = new GCHeapDump(fileName);
+            var heapSnapshot = new HeapSnapshot(heapDump);
+            heapView.Snapshot = heapSnapshot;
+        }
+        catch (Exception ex)
+        {
+            // TODO: Show error
+        }
+    }
+
+    private void DragOver(object? sender, DragEventArgs e)
+    {
+        if (!e.Data.Contains(DataFormats.Files) || e.Data.GetFiles()?.FirstOrDefault() is not IStorageFile)
+            e.DragEffects = DragDropEffects.None;
+        else
+            e.DragEffects = DragDropEffects.Move;
+    }
 
-        heapView.Snapshot = heapSnapshot;
+    private void Drop(object? sender, DragEventArgs e)
+    {
+        if (e.Data.Contains(DataFormats.Files))
+        {
+            var files = e.Data.GetFiles()?.OfType<IStorageFile>().ToArray();
+            if (files?.FirstOrDefault()?.TryGetLocalPath() is string path)
+            {
+                Open(path);
+            }
+        }
     }
 }

src/OneHub.Tools.HeapView/Program.cs

@@ -9,19 +9,19 @@ class Program
     [STAThread]
     public static int Main(string[] args)
     {
-        var fileNameArgument = new Argument<string>("filename", "Path to .gcdump file");
+        var fileNameArgument = new Argument<string?>("filename", () => null, "Path to .gcdump file");
         var cmd = new RootCommand { fileNameArgument };
         cmd.SetHandler(HandleView, fileNameArgument);
         return cmd.Invoke(args);
     }
 
-    static void HandleView(string inputFileName)
+    static void HandleView(string? inputFileName)
     {
         AppBuilder
             .Configure<App>()
             .UsePlatformDetect()
             .WithInterFont()
             .LogToTrace()
-            .StartWithClassicDesktopLifetime(new[] { inputFileName });
+            .StartWithClassicDesktopLifetime(inputFileName != null ? new[] { inputFileName } : Array.Empty<string>());
     }
 }

src/OneHub.Tools.HeapView/Properties/launchSettings.json

@@ -0,0 +1,7 @@
+{
+  "profiles": {
+    "dotnet-heapview": {
+      "commandName": "Project"
+    }
+  }
+}