Merge pull request #70 from AvaloniaUI/features/dialog-focus

Add API to focus NativeWebDialog

Author: maxkatz6

src/Avalonia.Controls.WebView.Core/Android/AndroidNativeWebViewDialog.cs

@@ -80,6 +80,8 @@ private async void ShowCore(IPlatformHandle? owner)
         _isOpen = true;
     }
 
+    public void Focus() => (TryGetAdapter() as IWebViewAdapterWithFocus)?.Focus();
+
     public void Close()
     {
         if (!_isOpen || _context is null) return;

src/Avalonia.Controls.WebView.Core/Browser/BrowserWindowNativeWebViewDialog.cs

@@ -94,6 +94,13 @@ public bool Show(IPlatformHandle owner)
         return true;
     }
 
+    public void Focus()
+    {
+        if (_popup is { } popup)
+            WebViewInterop.FocusDialogWindow(popup);
+        (_adapter as IWebViewAdapterWithFocus)?.Focus();
+    }
+
     public void Close()
     {
         if (_popup is { } popup)

src/Avalonia.Controls.WebView.Core/Browser/WebViewInterop.cs

@@ -96,6 +96,9 @@ public static partial Action SubscribeMessages(
     [JSImport("closeDialogWindow", "av-webview")]
     public static partial void CloseDialogWindow(JSObject popup);
 
+    [JSImport("focusDialogWindow", "av-webview")]
+    public static partial void FocusDialogWindow(JSObject popup);
+
     [JSImport("resizeDialogWindow", "av-webview")]
     public static partial bool ResizeDialogWindow(JSObject popup, int width, int height);
 

src/Avalonia.Controls.WebView.Core/Gtk/GtkNativeWebViewDialog.cs

@@ -215,6 +215,12 @@ public bool Show(IPlatformHandle owner)
         return true;
     }
 
+    public void Focus() => RunOnGlibThreadAsync(() =>
+    {
+        gtk_window_present(_windowHandle);
+        _nativeWebView?.Focus();
+    });
+
     public void Close()
     {
         // Closing is invoked in two places for the GTK webview:

src/Avalonia.Controls.WebView.Core/IWebViewAdapter.cs

@@ -178,6 +178,11 @@ internal interface INativeWebViewDialog : IDisposable
     /// </summary>
     void Close();
 
+    /// <summary>
+    /// Activates the dialog and moves keyboard focus to the hosted web content.
+    /// </summary>
+    void Focus();
+
     /// <summary>
     /// Resizes the WebView dialog.
     /// </summary>

src/Avalonia.Controls.WebView.Core/staticwebassets/av-webview.mjs

@@ -170,6 +170,12 @@ export function closeDialogWindow(popup) {
     } catch { }
 }
 
+export function focusDialogWindow(popup) {
+    try {
+        popup.focus();
+    } catch { }
+}
+
 export function resizeDialogWindow(popup, width, height) {
     try {
         popup.resizeTo(width, height);

src/Avalonia.Controls.WebView/EmptyNativeWebViewControlImpl.cs

@@ -27,6 +27,8 @@ internal class EmptyNativeWebViewControlImpl : Control, INativeWebViewControlImp
 
     public Task<IWebViewAdapter?> GetAdapterAsync() => Task.FromResult<IWebViewAdapter?>(null);
 
+    public void FocusWebView() { }
+
     public IDisposable BeginReparenting(bool yieldOnLayoutBeforeExiting) => EmptyDisposable.Instance;
     public IAsyncDisposable BeginReparentingAsync() => EmptyDisposable.Instance;
 

src/Avalonia.Controls.WebView/INativeWebViewControlImpl.cs

@@ -27,6 +27,11 @@ internal interface INativeWebViewControlImpl
     /// </summary>
     Task<IWebViewAdapter?> GetAdapterAsync();
 
+    /// <summary>
+    /// Moves keyboard focus to the hosted web content, if it's already initialized.
+    /// </summary>
+    void FocusWebView();
+
     /// <inheritdoc cref="NativeWebView.BeginReparenting"/>.
     IDisposable BeginReparenting(bool yieldOnLayoutBeforeExiting);
 

src/Avalonia.Controls.WebView/NativeWebDialog.cs

@@ -45,6 +45,8 @@ public class NativeWebDialog : Core.IWebView, Core.IWebViewHolder, IDisposable
         private Color? _initialDefaultBackground;
         private bool _disposed;
         private bool _dialogInitialized;
+        private bool _shown;
+        private bool _focusRequested;
 
         static NativeWebDialog()
         {
@@ -299,10 +301,19 @@ public Color? DefaultBackground
             }
         }
 
+        /// <summary>
+        /// Gets or sets if the dialog moves keyboard focus to its web content when shown. Default is true.
+        /// </summary>
+        public bool ShowFocused { get; set; } = true;
+
         /// <inheritdoc cref="Core.INativeWebViewDialog.Closing"/>
         public event EventHandler? Closing;
         /// <inheritdoc cref="Core.INativeWebViewDialog.Show()"/>
-        public async void Show() => (await GetOrInitialize()).Show();
+        public async void Show()
+        {
+            (await GetOrInitialize()).Show();
+            OnShown();
+        }
 
 #if WPF
         /// <summary>
@@ -345,6 +356,39 @@ public async void Show(TopLevel owner)
             {
                 impl.Show();
             }
+
+            OnShown();
+        }
+
+        /// <summary>
+        /// Activates the dialog and moves keyboard focus to the web content hosted inside of it.
+        /// </summary>
+        public void Focus()
+        {
+            _focusRequested = true;
+            TryApplyFocus();
+        }
+
+        private void OnShown()
+        {
+            _shown = true;
+            _focusRequested |= ShowFocused;
+            TryApplyFocus();
+        }
+
+        private void TryApplyFocus()
+        {
+            // The adapter is typically created only after the dialog window was shown,
+            // and native focus can't be moved before that.
+            if (!_focusRequested || !_shown
+                || TryGetImpl() is not { } impl
+                || impl.TryGetAdapter() is null)
+            {
+                return;
+            }
+
+            _focusRequested = false;
+            impl.Focus();
         }
 
 #if WPF
@@ -501,6 +545,7 @@ private void DialogImplOnAdapterDestroyed(object? sender, Core.WebViewAdapterEve
             adapter.WebResourceRequested -= WebViewAdapterOnWebResourceRequested;
             adapter.NewWindowRequested -= WebViewAdapterOnNewWindowRequested;
             _dialogInitialized = false;
+            _shown = false;
             AdapterDestroyed?.Invoke(this, e);
         }
 
@@ -532,6 +577,8 @@ private void DialogImplOnAdapterCreated(object? sender, Core.WebViewAdapterEvent
             else if (_lastSource is ValueTuple<string, Uri?> pair)
                 adapter.NavigateToString(pair.Item1, pair.Item2);
             AdapterCreated?.Invoke(this, e);
+
+            TryApplyFocus();
         }
 
         private void DialogImplOnClosing(object? sender, EventArgs e)

src/Avalonia.Controls.WebView/NativeWebViewCompositorHost.cs

@@ -44,6 +44,9 @@ static NativeWebViewCompositorHost()
         _webViewReadyCompletion.Task.Result :
         null;
 
+    /// <inheritdoc />
+    public void FocusWebView() => Focus();
+
     /// <inheritdoc />
     public async Task<IWebViewAdapter?> GetAdapterAsync() =>
         _webViewReadyCompletion is null ? null : await _webViewReadyCompletion.Task;