fix(canvas): repair fullscreen WebView bridge

Send fullscreen shortcut messages as object-root WebView bridge payloads, guard bridge parsing against non-object roots, and use shared fullscreen message constants.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 2 people

src/OpenClaw.Shared/WebBridgeMessage.cs

@@ -46,6 +46,12 @@ public WebBridgeMessage(string type, string? payloadJson = null)
     /// <summary>Sent SPA→native when the SPA is fully initialised and ready for messages.</summary>
     public const string TypeReady = "ready";
 
+    /// <summary>Sent SPA→native to toggle the owning canvas window fullscreen state.</summary>
+    public const string TypeFullscreenToggle = "fullscreen-toggle";
+
+    /// <summary>Sent SPA→native to exit fullscreen on the owning canvas window.</summary>
+    public const string TypeFullscreenExit = "fullscreen-exit";
+
     // ── parsing ────────────────────────────────────────────────────────────
 
     /// <summary>
@@ -62,6 +68,9 @@ public WebBridgeMessage(string type, string? payloadJson = null)
             using var doc = JsonDocument.Parse(json);
             var root = doc.RootElement;
 
+            if (root.ValueKind != JsonValueKind.Object)
+                return null;
+
             if (!root.TryGetProperty("type", out var typeEl) || typeEl.ValueKind != JsonValueKind.String)
                 return null;
 

src/OpenClaw.Tray.WinUI/Windows/A2UICanvasWindow.xaml.cs

@@ -5,8 +5,10 @@
 using System.Text.Json.Nodes;
 using System.Threading.Tasks;
 using Microsoft.UI.Dispatching;
+using Microsoft.UI.Windowing;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Input;
 using Microsoft.UI.Xaml.Media.Imaging;
 using OpenClaw.Shared;
 using OpenClawTray.A2UI.Actions;
@@ -16,6 +18,7 @@
 using WinUIEx;
 using Windows.Graphics.Imaging;
 using Windows.Storage.Streams;
+using Windows.System;
 
 namespace OpenClawTray.Windows;
 
@@ -42,9 +45,10 @@ public sealed partial class A2UICanvasWindow : WindowEx
     private const uint SWP_NOSIZE = 0x0001;
     private const uint SWP_SHOWWINDOW = 0x0040;
 
-    private readonly DispatcherQueue _dispatcher;
+    private readonly Microsoft.UI.Dispatching.DispatcherQueue _dispatcher;
     private readonly A2UIRouter _router;
     private readonly DataModelStore _dataModel;
+    private bool _isFullScreen;
 
     public bool IsClosed { get; private set; }
 
@@ -61,14 +65,30 @@ public A2UICanvasWindow(IActionSink actions, MediaResolver media, IOpenClawLogge
         Title = OpenClawTray.Helpers.LocalizationHelper.GetString("A2UI_CanvasTitle");
         WaitingForContentText.Text = OpenClawTray.Helpers.LocalizationHelper.GetString("Canvas_WaitingForContent");
 
-        _dispatcher = DispatcherQueue.GetForCurrentThread();
+        _dispatcher = Microsoft.UI.Dispatching.DispatcherQueue.GetForCurrentThread();
         _dataModel = new DataModelStore(_dispatcher);
         var registry = ComponentRendererRegistry.BuildDefault(media);
         _router = new A2UIRouter(_dispatcher, _dataModel, registry, actions, logger);
 
         _router.SurfaceCreated += OnSurfaceCreated;
         _router.SurfaceDeleted += OnSurfaceDeleted;
 
+        // F11 toggles borderless fullscreen; Escape exits it.
+        var f11Accel = new KeyboardAccelerator { Key = VirtualKey.F11 };
+        f11Accel.Invoked += (_, args) =>
+        {
+            args.Handled = true;
+            ToggleFullScreen();
+        };
+        var escAccel = new KeyboardAccelerator { Key = VirtualKey.Escape };
+        escAccel.Invoked += (_, args) =>
+        {
+            if (_isFullScreen) { args.Handled = true; ExitFullScreen(); }
+        };
+        RootGrid.KeyboardAccelerators.Add(f11Accel);
+        RootGrid.KeyboardAccelerators.Add(escAccel);
+        RootGrid.KeyboardAcceleratorPlacementMode = KeyboardAcceleratorPlacementMode.Hidden;
+
         // Explicit teardown: unsubscribe router events and reset surfaces so
         // the router's component subscriptions don't outlive the window. The
         // router holds back-references via event delegates; without this, a
@@ -77,6 +97,7 @@ public A2UICanvasWindow(IActionSink actions, MediaResolver media, IOpenClawLogge
         Closed += (_, _) =>
         {
             IsClosed = true;
+            ExitFullScreen();
             try { _router.SurfaceCreated -= OnSurfaceCreated; }
             catch (Exception ex) { OpenClawTray.Services.Logger.Debug($"A2UICanvasWindow: unsubscribe SurfaceCreated failed: {ex.Message}"); }
             try { _router.SurfaceDeleted -= OnSurfaceDeleted; }
@@ -338,6 +359,30 @@ public string GetStateSnapshot()
         return snapshot.ToJsonString();
     }
 
+    // ── Fullscreen ──────────────────────────────────────────────────────────
+
+    /// <summary>Toggle borderless fullscreen on F11.</summary>
+    public void ToggleFullScreen()
+    {
+        if (_isFullScreen) ExitFullScreen();
+        else EnterFullScreen();
+    }
+
+    private void EnterFullScreen()
+    {
+        _isFullScreen = true;
+        try { AppWindow.SetPresenter(AppWindowPresenterKind.FullScreen); }
+        catch (Exception ex) { OpenClawTray.Services.Logger.Debug($"A2UICanvasWindow: EnterFullScreen failed: {ex.Message}"); }
+    }
+
+    private void ExitFullScreen()
+    {
+        if (!_isFullScreen) return;
+        _isFullScreen = false;
+        try { AppWindow.SetPresenter(AppWindowPresenterKind.Default); }
+        catch (Exception ex) { OpenClawTray.Services.Logger.Debug($"A2UICanvasWindow: ExitFullScreen failed: {ex.Message}"); }
+    }
+
     public void BringToFront(bool keepTopMost = false)
     {
         try

src/OpenClaw.Tray.WinUI/Windows/CanvasWindow.xaml.cs

@@ -5,15 +5,18 @@
 using System.Threading.Tasks;
 using System.Runtime.InteropServices;
 using Microsoft.UI.Dispatching;
+using Microsoft.UI.Windowing;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Automation;
+using Microsoft.UI.Xaml.Input;
 using Microsoft.Web.WebView2.Core;
 using OpenClaw.Shared;
 using OpenClawTray.Helpers;
 using OpenClawTray.Services;
 using WinUIEx;
 using Windows.Foundation;
 using Windows.Storage.Streams;
+using Windows.System;
 
 namespace OpenClawTray.Windows;
 
@@ -39,6 +42,7 @@ public sealed partial class CanvasWindow : WindowEx
     private const uint SWP_SHOWWINDOW = 0x0040;
 
     private bool _isWebViewInitialized;
+    private bool _isFullScreen;
     private string? _pendingUrl;
     private string? _pendingHtml;
     private readonly TaskCompletionSource<bool> _webViewReadyTcs = new(TaskCreationOptions.RunContinuationsAsynchronously);
@@ -50,7 +54,7 @@ public sealed partial class CanvasWindow : WindowEx
     private FileSystemWatcher? _canvasWatcher;
     private long _lastReloadTicks = 0;
 
-    private readonly DispatcherQueue? _dispatcherQueue;
+    private readonly Microsoft.UI.Dispatching.DispatcherQueue? _dispatcherQueue;
     private TypedEventHandler<CoreWebView2, CoreWebView2WebMessageReceivedEventArgs>? _webMessageReceivedHandler;
     private TypedEventHandler<CoreWebView2, CoreWebView2WebResourceRequestedEventArgs>? _webResourceRequestedHandler;
     private string? _webResourceRequestedFilter;
@@ -235,7 +239,30 @@ public CanvasWindow()
         this.SetIcon("Assets\\openclaw.ico");
         _dispatcherQueue = DispatcherQueue;
         this.Closed += OnWindowClosed;
-        
+
+        // F11 toggles borderless fullscreen; Escape exits it.
+        // KeyboardAccelerators on the root content get first-class handling
+        // when focus is in the XAML tree (title bar, toolbar, etc.).
+        // When focus is inside the WebView2, F11/Escape are also intercepted
+        // via an injected content script that posts bridge messages.
+        if (this.Content is FrameworkElement contentRoot)
+        {
+            var f11Accel = new KeyboardAccelerator { Key = VirtualKey.F11 };
+            f11Accel.Invoked += (_, args) =>
+            {
+                args.Handled = true;
+                ToggleFullScreen();
+            };
+            var escAccel = new KeyboardAccelerator { Key = VirtualKey.Escape };
+            escAccel.Invoked += (_, args) =>
+            {
+                if (_isFullScreen) { args.Handled = true; ExitFullScreen(); }
+            };
+            contentRoot.KeyboardAccelerators.Add(f11Accel);
+            contentRoot.KeyboardAccelerators.Add(escAccel);
+            contentRoot.KeyboardAcceleratorPlacementMode = KeyboardAcceleratorPlacementMode.Hidden;
+        }
+
         // Initialize WebView2
         InitializeWebViewAsync();
     }
@@ -284,6 +311,24 @@ private async Task InitializeWebViewCoreAsync()
             CanvasWebView.CoreWebView2.Settings.IsStatusBarEnabled = false;
             CanvasWebView.CoreWebView2.Settings.AreDevToolsEnabled = false;
 
+            // Inject F11/Escape fullscreen bridge: intercepts these keys when
+            // WebView2 content has focus and routes them as bridge messages so
+            // the native window can toggle its presenter the same way the XAML
+            // keyboard accelerators do when focus is in the title bar.
+            await CanvasWebView.CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync("""
+                (function () {
+                    document.addEventListener('keydown', function (e) {
+                        if (!window.chrome || !window.chrome.webview) return;
+                        if (e.key === 'F11') {
+                            e.preventDefault();
+                            window.chrome.webview.postMessage({ type: 'fullscreen-toggle' });
+                        } else if (e.key === 'Escape') {
+                            window.chrome.webview.postMessage({ type: 'fullscreen-exit' });
+                        }
+                    }, true);
+                })();
+                """);
+
             // Wire the bidirectional native↔SPA bridge
             // SPA → native: window.chrome.webview.postMessage({ type, payload })
             _webMessageReceivedHandler = (s, e) =>
@@ -297,6 +342,19 @@ private async Task InitializeWebViewCoreAsync()
                 var msg = WebBridgeMessage.TryParse(e.WebMessageAsJson);
                 if (msg != null)
                 {
+                    // Fullscreen control messages are handled natively and not
+                    // forwarded to external bridge subscribers.
+                    if (msg.Type == WebBridgeMessage.TypeFullscreenToggle)
+                    {
+                        _dispatcherQueue?.TryEnqueue(ToggleFullScreen);
+                        return;
+                    }
+                    if (msg.Type == WebBridgeMessage.TypeFullscreenExit)
+                    {
+                        _dispatcherQueue?.TryEnqueue(ExitFullScreen);
+                        return;
+                    }
+
                     Logger.Debug($"[Canvas] bridge message from SPA, type={SanitizeBridgeLogValue(msg.Type)}");
                     BridgeMessageReceived?.Invoke(this, msg);
                 }
@@ -473,6 +531,7 @@ private void OnCanvasFileChanged(object sender, FileSystemEventArgs e)
     private void OnWindowClosed(object sender, WindowEventArgs args)
     {
         IsClosed = true;
+        ExitFullScreen();
         _gatewayToken = null;
 
         if (CanvasWebView.CoreWebView2 != null)
@@ -659,6 +718,30 @@ public void BringToFront(bool keepTopMost)
         }
     }
 
+    // ── Fullscreen ──────────────────────────────────────────────────────────
+
+    /// <summary>Toggle borderless fullscreen on F11.</summary>
+    public void ToggleFullScreen()
+    {
+        if (_isFullScreen) ExitFullScreen();
+        else EnterFullScreen();
+    }
+
+    private void EnterFullScreen()
+    {
+        _isFullScreen = true;
+        try { AppWindow.SetPresenter(AppWindowPresenterKind.FullScreen); }
+        catch (Exception ex) { Logger.Debug($"[Canvas] EnterFullScreen failed: {ex.Message}"); }
+    }
+
+    private void ExitFullScreen()
+    {
+        if (!_isFullScreen) return;
+        _isFullScreen = false;
+        try { AppWindow.SetPresenter(AppWindowPresenterKind.Default); }
+        catch (Exception ex) { Logger.Debug($"[Canvas] ExitFullScreen failed: {ex.Message}"); }
+    }
+
     public async Task EnsureA2UIHostAsync(string url)
     {
         await EnsureWebViewReadyAsync();

tests/OpenClaw.Shared.Tests/WebBridgeMessageTests.cs

@@ -53,6 +53,16 @@ public void TryParse_InvalidJson_ReturnsNull()
         Assert.Null(WebBridgeMessage.TryParse("{bad json"));
     }
 
+    [Fact]
+    public void TryParse_StringRoot_ReturnsNull()
+    {
+        var jsonStringRoot = """
+            "{\"type\":\"fullscreen-toggle\"}"
+            """;
+
+        Assert.Null(WebBridgeMessage.TryParse(jsonStringRoot));
+    }
+
     [Fact]
     public void TryParse_TypeIsNotString_ReturnsNull()
     {
@@ -129,6 +139,8 @@ public void ToJson_PassedPayloadOverridesStoredPayloadJson()
     [InlineData(WebBridgeMessage.TypeVoiceStart)]
     [InlineData(WebBridgeMessage.TypeVoiceStop)]
     [InlineData(WebBridgeMessage.TypeReady)]
+    [InlineData(WebBridgeMessage.TypeFullscreenToggle)]
+    [InlineData(WebBridgeMessage.TypeFullscreenExit)]
     public void RoundTrip_WellKnownTypes_PreserveType(string type)
     {
         var original = new WebBridgeMessage(type);