Add automatic focusing of the WebView2 widget.

cmd/demo/main.go

@@ -8,7 +8,8 @@ import (
 
 func main() {
 	w := webview2.NewWithOptions(webview2.WebViewOptions{
-		Debug: true,
+		Debug:     true,
+		AutoFocus: true,
 		WindowOptions: webview2.WindowOptions{
 			Title: "Minimal webview example",
 		},

internal/w32/w32.go

@@ -63,6 +63,7 @@ const (
 	WMDestroy       = 0x0002
 	WMMove          = 0x0003
 	WMSize          = 0x0005
+	WMActivate      = 0x0006
 	WMClose         = 0x0010
 	WMQuit          = 0x0012
 	WMGetMinMaxInfo = 0x0024
@@ -91,6 +92,12 @@ const (
 	WSOverlappedWindow = (WSOverlapped | WSCaption | WSSysMenu | WSThickFrame | WSMinimizeBox | WSMaximizeBox)
 )
 
+const (
+	WAInactive    = 0
+	WAActive      = 1
+	WAActiveClick = 2
+)
+
 type WndClassExW struct {
 	CbSize        uint32
 	Style         uint32

pkg/edge/COREWEBVIEW2_MOVE_FOCUS_REASON.go

@@ -0,0 +1,9 @@
+package edge
+
+type COREWEBVIEW2_MOVE_FOCUS_REASON uint32
+
+const (
+	COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC = 0
+	COREWEBVIEW2_MOVE_FOCUS_REASON_NEXT         = 1
+	COREWEBVIEW2_MOVE_FOCUS_REASON_PREVIOUS     = 2
+)

pkg/edge/ICoreWebView2Controller.go

@@ -118,3 +118,15 @@ func (i *ICoreWebView2Controller) NotifyParentWindowPositionChanged() error {
 	}
 	return nil
 }
+
+func (i *ICoreWebView2Controller) MoveFocus(reason uintptr) error {
+	var err error
+	_, _, err = i.vtbl.MoveFocus.Call(
+		uintptr(unsafe.Pointer(i)),
+		uintptr(reason),
+	)
+	if err != windows.ERROR_SUCCESS {
+		return err
+	}
+	return nil
+}

pkg/edge/chromium.go

@@ -16,6 +16,7 @@ import (
 
 type Chromium struct {
 	hwnd                  uintptr
+	focusOnInit           bool
 	controller            *ICoreWebView2Controller
 	webview               *ICoreWebView2
 	inited                uintptr
@@ -216,6 +217,10 @@ func (e *Chromium) CreateCoreWebView2ControllerCompleted(res uintptr, controller
 
 	atomic.StoreUintptr(&e.inited, 1)
 
+	if e.focusOnInit {
+		e.Focus()
+	}
+
 	return 0
 }
 
@@ -340,3 +345,11 @@ func (e *Chromium) NotifyParentWindowPositionChanged() error {
 	}
 	return e.controller.NotifyParentWindowPositionChanged()
 }
+
+func (e *Chromium) Focus() {
+	if e.controller == nil {
+		e.focusOnInit = true
+		return
+	}
+	_ = e.controller.MoveFocus(COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC)
+}

webview.go

@@ -42,12 +42,14 @@ type browser interface {
 	Init(script string)
 	Eval(script string)
 	NotifyParentWindowPositionChanged() error
+	Focus()
 }
 
 type webview struct {
 	hwnd       uintptr
 	mainthread uintptr
 	browser    browser
+	autofocus  bool
 	maxsz      w32.Point
 	minsz      w32.Point
 	m          sync.Mutex
@@ -60,10 +62,19 @@ type WindowOptions struct {
 }
 
 type WebViewOptions struct {
-	Window   unsafe.Pointer
-	Debug    bool
+	Window unsafe.Pointer
+	Debug  bool
+
+	// DataPath specifies the datapath for the WebView2 runtime to use for the
+	// browser instance.
 	DataPath string
 
+	// AutoFocus will try to keep the WebView2 widget focused when the window
+	// is focused.
+	AutoFocus bool
+
+	// WindowOptions customizes the window that is created to embed the
+	// WebView2 widget.
 	WindowOptions WindowOptions
 }
 
@@ -81,6 +92,7 @@ func NewWindow(debug bool, window unsafe.Pointer) WebView {
 func NewWithOptions(options WebViewOptions) WebView {
 	w := &webview{}
 	w.bindings = map[string]interface{}{}
+	w.autofocus = options.AutoFocus
 
 	chromium := edge.NewChromium()
 	chromium.MessageCallback = w.msgcb
@@ -198,6 +210,13 @@ func wndproc(hwnd, msg, wp, lp uintptr) uintptr {
 			return r
 		case w32.WMSize:
 			w.browser.Resize()
+		case w32.WMActivate:
+			if wp == w32.WAInactive {
+				break
+			}
+			if w.autofocus {
+				w.browser.Focus()
+			}
 		case w32.WMClose:
 			_, _, _ = w32.User32DestroyWindow.Call(hwnd)
 		case w32.WMDestroy: