Implement programmatic SnapAssist for v3

v3/examples/window/main.go

@@ -701,6 +701,14 @@ func main() {
 			w.OpenDevTools()
 		})
 	})
+
+	if runtime.GOOS == "windows" {
+		stateMenu.Add("Show SnapAssist").OnClick(func(ctx *application.Context) {
+			currentWindow(func(w *application.WebviewWindow) {
+				w.ShowSnapAssist()
+			})
+		})
+	}
 
 	if runtime.GOOS != "darwin" {
 		stateMenu.Add("Flash for 5s").OnClick(func(ctx *application.Context) {

v3/pkg/application/webview_window.go

@@ -107,6 +107,7 @@ type (
 		selectAll()
 		redo()
 		showMenuBar()
+		showSnapAssist()
 		hideMenuBar()
 		toggleMenuBar()
 		setMenu(menu *Menu)
@@ -458,6 +459,7 @@ func (w *WebviewWindow) Show() Window {
 	return w
 }
 
+
 // Hide hides the window.
 func (w *WebviewWindow) Hide() Window {
 	w.options.Hidden = true
@@ -1413,6 +1415,15 @@ func (w *WebviewWindow) ShowMenuBar() {
 	InvokeSync(w.impl.showMenuBar)
 }
 
+// ShowSnapAssist shows the Windows SnapAssist overlay for this window.
+// This is a Windows-only feature and does nothing on other platforms.
+func (w *WebviewWindow) ShowSnapAssist() {
+	if w.impl == nil || w.isDestroyed() {
+		return
+	}
+	InvokeSync(w.impl.showSnapAssist)
+}
+
 // HideMenuBar hides the menu bar for the window.
 func (w *WebviewWindow) HideMenuBar() {
 	if w.impl == nil || w.isDestroyed() {

v3/pkg/application/webview_window_darwin.go

@@ -1435,6 +1435,7 @@ func (w *macosWebviewWindow) redo() {
 }
 
 func (w *macosWebviewWindow) showMenuBar()    {}
+func (w *macosWebviewWindow) showSnapAssist() {}
 func (w *macosWebviewWindow) hideMenuBar()    {}
 func (w *macosWebviewWindow) toggleMenuBar()  {}
 func (w *macosWebviewWindow) setMenu(_ *Menu) {}

v3/pkg/application/webview_window_linux.go

@@ -425,5 +425,6 @@ func (w *linuxWebviewWindow) hide() {
 }
 
 func (w *linuxWebviewWindow) showMenuBar()   {}
+func (w *linuxWebviewWindow) showSnapAssist() {}
 func (w *linuxWebviewWindow) hideMenuBar()   {}
 func (w *linuxWebviewWindow) toggleMenuBar() {}

v3/pkg/application/webview_window_windows.go

@@ -2276,8 +2276,73 @@ func (w *windowsWebviewWindow) showMenuBar() {
 	}
 }
 
+func (w *windowsWebviewWindow) showSnapAssist() {
+	// Ensure this window is focused first
+	w32.SetForegroundWindow(w.hwnd)
+
+	// Send Win+Z key combination to trigger SnapAssist
+	w.sendKeyCombo(0x5A, 0x5B) // Z key with Windows key
+}
+
 func (w *windowsWebviewWindow) hideMenuBar() {
 	if w.menu != nil {
 		w32.SetMenu(w.hwnd, 0)
 	}
 }
+
+// sendKeyCombo sends a key combination (key + modifier)
+func (w *windowsWebviewWindow) sendKeyCombo(key, modifier uint16) {
+	// Create input array for key combination
+	inputs := make([]w32.INPUT, 4)
+
+	// Modifier key down (Windows key)
+	inputs[0] = w32.INPUT{
+		Type: 1, // INPUT_KEYBOARD
+		Ki: w32.KEYBDINPUT{
+			WVk:         modifier,
+			WScan:       0,
+			DwFlags:     0,
+			Time:        0,
+			DwExtraInfo: 0,
+		},
+	}
+
+	// Main key down (Z key)
+	inputs[1] = w32.INPUT{
+		Type: 1, // INPUT_KEYBOARD
+		Ki: w32.KEYBDINPUT{
+			WVk:         key,
+			WScan:       0,
+			DwFlags:     0,
+			Time:        0,
+			DwExtraInfo: 0,
+		},
+	}
+
+	// Main key up (Z key)
+	inputs[2] = w32.INPUT{
+		Type: 1, // INPUT_KEYBOARD
+		Ki: w32.KEYBDINPUT{
+			WVk:         key,
+			WScan:       0,
+			DwFlags:     0x0002, // KEYEVENTF_KEYUP
+			Time:        0,
+			DwExtraInfo: 0,
+		},
+	}
+
+	// Modifier key up (Windows key)
+	inputs[3] = w32.INPUT{
+		Type: 1, // INPUT_KEYBOARD
+		Ki: w32.KEYBDINPUT{
+			WVk:         modifier,
+			WScan:       0,
+			DwFlags:     0x0002, // KEYEVENTF_KEYUP
+			Time:        0,
+			DwExtraInfo: 0,
+		},
+	}
+
+	// Send the input events
+	w32.SendInput(len(inputs), unsafe.Pointer(&inputs[0]), int(unsafe.Sizeof(w32.INPUT{})))
+}

v3/pkg/application/window.go

@@ -71,6 +71,7 @@ type Window interface {
 	SetZoom(magnification float64) Window
 	Show() Window
 	ShowMenuBar()
+	ShowSnapAssist()
 	Size() (width int, height int)
 	OpenDevTools()
 	ToggleFullscreen()

v3/pkg/application/window_manager.go

@@ -133,3 +133,4 @@ func (wm *WindowManager) GetAll() []Window {
 	}
 	return windows
 }
+

v3/pkg/application/window_manager_darwin.go

@@ -0,0 +1,8 @@
+//go:build darwin
+
+package application
+
+// showSnapAssist is a no-op on macOS as SnapAssist is a Windows-only feature
+func showSnapAssist(window *WebviewWindow) {
+	// SnapAssist is not available on macOS
+}

v3/pkg/application/window_manager_linux.go

@@ -0,0 +1,8 @@
+//go:build linux
+
+package application
+
+// showSnapAssist is a no-op on Linux as SnapAssist is a Windows-only feature
+func showSnapAssist(window *WebviewWindow) {
+	// SnapAssist is not available on Linux
+}

v3/pkg/application/window_manager_windows.go

@@ -0,0 +1,95 @@
+//go:build windows
+
+package application
+
+import (
+	"time"
+	"unsafe"
+
+	"github.com/wailsapp/wails/v3/pkg/w32"
+)
+
+// showSnapAssist sends Win+Z key combination to trigger SnapAssist for the specified window
+func showSnapAssist(window *WebviewWindow) {
+	// First, ensure the window is visible and focused to target SnapAssist correctly
+	window.Show()    // Ensure window is visible
+	window.Restore() // Restore if minimized
+
+	// Get the native window handle and set it as foreground
+	if hwnd := w32.HWND(window.impl.nativeWindowHandle()); hwnd != 0 {
+		w32.SetForegroundWindow(hwnd)
+		// Small delay to ensure window focus is established
+		time.Sleep(50 * time.Millisecond)
+	}
+
+	// Send Win+Z key combination using a robotgo-style approach
+	sendKeyCombo(w32.VK_Z, w32.VK_LWIN)
+}
+
+// sendKeyCombo sends a key combination (key + modifiers)
+func sendKeyCombo(key uint16, modifiers ...uint16) {
+	// Calculate total inputs needed (press and release for each key)
+	numKeys := len(modifiers) + 1
+	inputs := make([]w32.INPUT, numKeys*2)
+
+	inputIndex := 0
+
+	// Press all modifier keys first
+	for _, modifier := range modifiers {
+		inputs[inputIndex] = w32.INPUT{
+			Type: w32.INPUT_KEYBOARD,
+			Ki: w32.KEYBDINPUT{
+				WVk:         modifier,
+				WScan:       0,
+				DwFlags:     0,
+				Time:        0,
+				DwExtraInfo: 0,
+			},
+		}
+		inputIndex++
+	}
+
+	// Press the main key
+	inputs[inputIndex] = w32.INPUT{
+		Type: w32.INPUT_KEYBOARD,
+		Ki: w32.KEYBDINPUT{
+			WVk:         key,
+			WScan:       0,
+			DwFlags:     0,
+			Time:        0,
+			DwExtraInfo: 0,
+		},
+	}
+	inputIndex++
+
+	// Release the main key
+	inputs[inputIndex] = w32.INPUT{
+		Type: w32.INPUT_KEYBOARD,
+		Ki: w32.KEYBDINPUT{
+			WVk:         key,
+			WScan:       0,
+			DwFlags:     w32.KEYEVENTF_KEYUP,
+			Time:        0,
+			DwExtraInfo: 0,
+		},
+	}
+	inputIndex++
+
+	// Release all modifier keys in reverse order
+	for i := len(modifiers) - 1; i >= 0; i-- {
+		inputs[inputIndex] = w32.INPUT{
+			Type: w32.INPUT_KEYBOARD,
+			Ki: w32.KEYBDINPUT{
+				WVk:         modifiers[i],
+				WScan:       0,
+				DwFlags:     w32.KEYEVENTF_KEYUP,
+				Time:        0,
+				DwExtraInfo: 0,
+			},
+		}
+		inputIndex++
+	}
+
+	// Send all input events
+	w32.SendInput(len(inputs), unsafe.Pointer(&inputs[0]), int(unsafe.Sizeof(w32.INPUT{})))
+}

v3/pkg/w32/constants.go

@@ -1994,6 +1994,7 @@ const (
 	VK_INSERT              = 0x2D
 	VK_DELETE              = 0x2E
 	VK_HELP                = 0x2F
+	VK_Z                   = 0x5A
 	VK_LWIN                = 0x5B
 	VK_RWIN                = 0x5C
 	VK_APPS                = 0x5D
@@ -2900,6 +2901,10 @@ const (
 	INPUT_HARDWARE = 2
 )
 
+const (
+	KEYEVENTF_KEYUP = 0x0002
+)
+
 const (
 	MOUSEEVENTF_ABSOLUTE        = 0x8000
 	MOUSEEVENTF_HWHEEL          = 0x01000
@@ -3555,6 +3560,7 @@ const (
 	VK_INSERT              = 45
 	VK_DELETE              = 46
 	VK_HELP                = 47
+	VK_Z                   = 0x5A
 	VK_LWIN                = 0x5B
 	VK_RWIN                = 0x5C
 	VK_APPS                = 0x5D

v3/pkg/w32/user32.go

@@ -1333,34 +1333,14 @@ func ChangeDisplaySettingsEx(szDeviceName *uint16, devMode *DEVMODE, hwnd HWND,
 	return int32(ret)
 }
 
-/*
-func SendInput(inputs []INPUT) uint32 {
-	var validInputs []C.INPUT
-
-	for _, oneInput := range inputs {
-		input := C.INPUT{_type: C.DWORD(oneInput.Type)}
-
-		switch oneInput.Type {
-		case INPUT_MOUSE:
-			(*MouseInput)(unsafe.Pointer(&input)).mi = oneInput.Mi
-		case INPUT_KEYBOARD:
-			(*KbdInput)(unsafe.Pointer(&input)).ki = oneInput.Ki
-		case INPUT_HARDWARE:
-			(*HardwareInput)(unsafe.Pointer(&input)).hi = oneInput.Hi
-		default:
-			panic("unkown type")
-		}
-
-		validInputs = append(validInputs, input)
-	}
-
+func SendInput(nInputs int, pInputs unsafe.Pointer, cbSize int) uint32 {
 	ret, _, _ := procSendInput.Call(
-		uintptr(len(validInputs)),
-		uintptr(unsafe.Pointer(&validInputs[0])),
-		uintptr(unsafe.Sizeof(C.INPUT{})),
+		uintptr(nInputs),
+		uintptr(pInputs),
+		uintptr(cbSize),
 	)
 	return uint32(ret)
-}*/
+}
 
 func SetWindowsHookEx(idHook int, lpfn HOOKPROC, hMod HINSTANCE, dwThreadId DWORD) HHOOK {
 	ret, _, _ := procSetWindowsHookEx.Call(