feature: V3 alpha feature/snapassist support (#4463)

* initial implementation

* Push missed files

* linux fix

* Update changelog, runtime and docs.

docs/src/content/docs/learn/windows.mdx

@@ -171,6 +171,37 @@ type Window interface {
 }
 ```
 
+### Common Window Methods
+
+Windows provide many methods for controlling their appearance and behavior:
+
+#### Display Control
+- `Show()` - Shows the window
+- `Hide()` - Hides the window
+- `SetTitle(title string)` - Sets the window title
+- `SetSize(width, height int)` - Sets the window size
+- `SetPosition(x, y int)` - Sets the window position
+- `Center()` - Centers the window on screen
+- `SetAlwaysOnTop(bool)` - Sets whether window stays on top
+
+#### Window State
+- `Minimise()` - Minimizes the window
+- `Maximise()` - Maximizes the window  
+- `UnMinimise()` - Restores from minimized state
+- `UnMaximise()` - Restores from maximized state
+- `Fullscreen()` - Enters fullscreen mode
+- `UnFullscreen()` - Exits fullscreen mode
+- `Restore()` - Restores window to normal state
+- `IsMinimised() bool` - Checks if window is minimized
+- `IsMaximised() bool` - Checks if window is maximized
+- `IsFullscreen() bool` - Checks if window is fullscreen
+
+#### Platform-Specific Methods
+
+**Windows Only:**
+- `Flash(bool)` - Flashes the taskbar button
+- `SnapAssist()` - Triggers Windows 11 Snap Assist (Win+Z)
+
 ## Advanced Window Management
 
 ### Multi-Window Applications
@@ -235,9 +266,18 @@ app.Event.On("data-updated", func(event *application.CustomEvent) {
     - Support custom window icons
     - Can be configured without system title bars
     - Follow Windows window management conventions
-    - Support Windows 11 snap layouts
+    - Support Windows 11 snap layouts via `SnapAssist()` method
     - Integrate with Windows taskbar features
     
+    **Windows 11 Snap Assist Example:**
+    ```go
+    // Trigger Windows 11 Snap Assist
+    window.SnapAssist()
+    
+    // This is equivalent to pressing Win+Z
+    // Shows snap layout options for the current window
+    ```
+    
   </TabItem>
   
   <TabItem label="Linux" icon="fa-brands:linux">

v3/UNRELEASED_CHANGELOG.md

@@ -17,6 +17,7 @@ After processing, the content will be moved to the main changelog and this file
 
 ### Added
 - Added Run go mod tidy automatically after wails init [@triadmoko](https://github.com/triadmoko) in [PR](https://github.com/wailsapp/wails/pull/4286)
+- Windows Snapassist feature by @leaanthony in [PR](https://github.dev/wailsapp/wails/pull/4463)
 
 ## Changed
 <!-- Changes in existing functionality -->

v3/examples/window/main.go

@@ -713,6 +713,14 @@ func main() {
 		})
 	}
 
+	if runtime.GOOS == "windows" {
+		stateMenu.Add("Snap Assist").OnClick(func(ctx *application.Context) {
+			currentWindow(func(w *application.WebviewWindow) {
+				w.SnapAssist()
+			})
+		})
+	}
+
 	printMenu := menu.AddSubmenu("Print")
 	printMenu.Add("Print").OnClick(func(ctx *application.Context) {
 		currentWindow(func(w *application.WebviewWindow) {

v3/internal/runtime/desktop/@wailsio/runtime/src/window.ts

@@ -60,6 +60,7 @@ const ZoomMethod                        = 45;
 const ZoomInMethod                      = 46;
 const ZoomOutMethod                     = 47;
 const ZoomResetMethod                   = 48;
+const SnapAssistMethod                  = 49;
 
 /**
  * A record describing the position of a window.
@@ -518,6 +519,14 @@ class Window {
     ZoomReset(): Promise<void> {
         return this[callerSym](ZoomResetMethod);
     }
+
+    /**
+     * Triggers Windows 11 Snap Assist feature (Windows only).
+     * This is equivalent to pressing Win+Z and shows snap layout options.
+     */
+    SnapAssist(): Promise<void> {
+        return this[callerSym](SnapAssistMethod);
+    }
 }
 
 /**

v3/pkg/application/messageprocessor_window.go

@@ -56,6 +56,7 @@ const (
 	WindowZoomIn                     = 46
 	WindowZoomOut                    = 47
 	WindowZoomReset                  = 48
+	WindowSnapAssist                 = 49
 )
 
 var windowMethodNames = map[int]string{
@@ -108,6 +109,7 @@ var windowMethodNames = map[int]string{
 	WindowZoomIn:                     "ZoomIn",
 	WindowZoomOut:                    "ZoomOut",
 	WindowZoomReset:                  "ZoomReset",
+	WindowSnapAssist:                 "SnapAssist",
 }
 
 func (m *MessageProcessor) processWindowMethod(
@@ -421,6 +423,9 @@ func (m *MessageProcessor) processWindowMethod(
 	case WindowZoomReset:
 		window.ZoomReset()
 		m.ok(rw)
+	case WindowSnapAssist:
+		window.SnapAssist()
+		m.ok(rw)
 	default:
 		m.httpError(rw, "Invalid window call:", fmt.Errorf("unknown method %d", method))
 		return

v3/pkg/application/webview_window.go

@@ -110,6 +110,7 @@ type (
 		hideMenuBar()
 		toggleMenuBar()
 		setMenu(menu *Menu)
+		snapAssist()
 	}
 )
 
@@ -1428,3 +1429,12 @@ func (w *WebviewWindow) ToggleMenuBar() {
 	}
 	InvokeSync(w.impl.toggleMenuBar)
 }
+
+// SnapAssist triggers the Windows Snap Assist feature by simulating Win+Z key combination.
+// On Windows, this opens the snap layout options. On Linux and macOS, this is a no-op.
+func (w *WebviewWindow) SnapAssist() {
+	if w.impl == nil || w.isDestroyed() {
+		return
+	}
+	InvokeSync(w.impl.snapAssist)
+}

v3/pkg/application/webview_window_darwin.go

@@ -1438,3 +1438,4 @@ func (w *macosWebviewWindow) showMenuBar()    {}
 func (w *macosWebviewWindow) hideMenuBar()    {}
 func (w *macosWebviewWindow) toggleMenuBar()  {}
 func (w *macosWebviewWindow) setMenu(_ *Menu) {}
+func (w *macosWebviewWindow) snapAssist()     {} // No-op on macOS

v3/pkg/application/webview_window_linux.go

@@ -427,3 +427,4 @@ func (w *linuxWebviewWindow) hide() {
 func (w *linuxWebviewWindow) showMenuBar()   {}
 func (w *linuxWebviewWindow) hideMenuBar()   {}
 func (w *linuxWebviewWindow) toggleMenuBar() {}
+func (w *linuxWebviewWindow) snapAssist()    {} // No-op on Linux

v3/pkg/application/webview_window_windows.go

@@ -2281,3 +2281,15 @@ func (w *windowsWebviewWindow) hideMenuBar() {
 		w32.SetMenu(w.hwnd, 0)
 	}
 }
+
+func (w *windowsWebviewWindow) snapAssist() {
+	// Simulate Win+Z key combination to trigger Snap Assist
+	// Press Windows key
+	w32.KeybdEvent(byte(w32.VK_LWIN), 0, 0, 0)
+	// Press Z key
+	w32.KeybdEvent(byte('Z'), 0, 0, 0)
+	// Release Z key
+	w32.KeybdEvent(byte('Z'), 0, w32.KEYEVENTF_KEYUP, 0)
+	// Release Windows key
+	w32.KeybdEvent(byte(w32.VK_LWIN), 0, w32.KEYEVENTF_KEYUP, 0)
+}

v3/pkg/application/window.go

@@ -86,4 +86,5 @@ type Window interface {
 	ZoomOut()
 	ZoomReset() Window
 	SetMenu(menu *Menu)
+	SnapAssist()
 }

v3/pkg/w32/constants.go

@@ -2900,6 +2900,13 @@ const (
 	INPUT_HARDWARE = 2
 )
 
+const (
+	KEYEVENTF_EXTENDEDKEY = 0x0001
+	KEYEVENTF_KEYUP       = 0x0002
+	KEYEVENTF_SCANCODE    = 0x0008
+	KEYEVENTF_UNICODE     = 0x0004
+)
+
 const (
 	MOUSEEVENTF_ABSOLUTE        = 0x8000
 	MOUSEEVENTF_HWHEEL          = 0x01000

v3/pkg/w32/user32.go

@@ -149,6 +149,7 @@ var (
 	procChangeDisplaySettingsEx       = moduser32.NewProc("ChangeDisplaySettingsExW")
 	procSetTimer                      = moduser32.NewProc("SetTimer")
 	procKillTimer                     = moduser32.NewProc("KillTimer")
+	procKeybdEvent                    = moduser32.NewProc("keybd_event")
 	procSendInput                     = moduser32.NewProc("SendInput")
 	procSetWindowsHookEx              = moduser32.NewProc("SetWindowsHookExW")
 	procUnhookWindowsHookEx           = moduser32.NewProc("UnhookWindowsHookEx")
@@ -1492,3 +1493,17 @@ func TrackPopupMenu(hmenu HMENU, flags uint32, x, y int32, reserved int32, hwnd
 		uintptr(unsafe.Pointer(prcRect)))
 	return ret != 0
 }
+
+// KeybdEvent synthesizes a keystroke. The system can use such a synthesized keystroke to generate a WM_KEYUP or WM_KEYDOWN message.
+// bVk: Virtual-key code
+// bScan: Hardware scan code
+// dwFlags: Controls various aspects of function operation (KEYEVENTF_EXTENDEDKEY or KEYEVENTF_KEYUP)
+// dwExtraInfo: Additional value associated with the keystroke
+func KeybdEvent(bVk byte, bScan byte, dwFlags uint32, dwExtraInfo uintptr) {
+	procKeybdEvent.Call(
+		uintptr(bVk),
+		uintptr(bScan),
+		uintptr(dwFlags),
+		dwExtraInfo,
+	)
+}