Fix Windows 32-bit support for GetWindowLong/SetWindowLong functions

internal/w32/w32.go

@@ -36,7 +36,9 @@ var (
 	User32PostMessageW       = user32.NewProc("PostMessageW")
 	User32SetWindowTextW     = user32.NewProc("SetWindowTextW")
 	User32PostThreadMessageW = user32.NewProc("PostThreadMessageW")
+	User32GetWindowLongW     = user32.NewProc("GetWindowLongW")
 	User32GetWindowLongPtrW  = user32.NewProc("GetWindowLongPtrW")
+	User32SetWindowLongW     = user32.NewProc("SetWindowLongW")
 	User32SetWindowLongPtrW  = user32.NewProc("SetWindowLongPtrW")
 	User32AdjustWindowRect   = user32.NewProc("AdjustWindowRect")
 	User32SetWindowPos       = user32.NewProc("SetWindowPos")

internal/w32/w32_386.go

@@ -0,0 +1,14 @@
+//go:build windows && 386
+// +build windows,386
+
+package w32
+
+func GetWindowLong(hwnd uintptr, index int) uintptr {
+	ret, _, _ := User32GetWindowLongW.Call(hwnd, uintptr(index))
+	return ret
+}
+
+func SetWindowLong(hwnd uintptr, index int, newLong uintptr) uintptr {
+	ret, _, _ := User32SetWindowLongW.Call(hwnd, uintptr(index), newLong)
+	return ret
+}

internal/w32/w32_64bit.go

@@ -0,0 +1,15 @@
+//go:build windows && (amd64 || arm64)
+// +build windows
+// +build amd64 arm64
+
+package w32
+
+func GetWindowLong(hwnd uintptr, index int) uintptr {
+	ret, _, _ := User32GetWindowLongPtrW.Call(hwnd, uintptr(index))
+	return ret
+}
+
+func SetWindowLong(hwnd uintptr, index int, newLong uintptr) uintptr {
+	ret, _, _ := User32SetWindowLongPtrW.Call(hwnd, uintptr(index), newLong)
+	return ret
+}

webview.go

@@ -404,13 +404,13 @@ func (w *webview) SetTitle(title string) {
 
 func (w *webview) SetSize(width int, height int, hints Hint) {
 	index := w32.GWLStyle
-	style, _, _ := w32.User32GetWindowLongPtrW.Call(w.hwnd, uintptr(index))
+	style := w32.GetWindowLong(w.hwnd, index)
 	if hints == HintFixed {
 		style &^= (w32.WSThickFrame | w32.WSMaximizeBox)
 	} else {
 		style |= (w32.WSThickFrame | w32.WSMaximizeBox)
 	}
-	_, _, _ = w32.User32SetWindowLongPtrW.Call(w.hwnd, uintptr(index), style)
+	w32.SetWindowLong(w.hwnd, index, style)
 
 	if hints == HintMax {
 		w.maxsz.X = int32(width)