Add configurable offline layout correction and latest Windows release

src/platform.cpp

@@ -107,9 +107,55 @@ wchar_t physicalKey(DWORD scan, bool shift)
             return (shift ? physicalLayout().shifted : physicalLayout().normal)[i];
     return 0;
 }
+static HWND inputWindow(HWND w)
+{
+    if (!w || !IsWindow(w))
+        return nullptr;
+    GUITHREADINFO info{sizeof(info)};
+    DWORD thread = w == GetForegroundWindow() ? 0 : GetWindowThreadProcessId(w, nullptr);
+    if (GetGUIThreadInfo(thread, &info) && info.hwndFocus &&
+        (info.hwndFocus == w || IsChild(w, info.hwndFocus) || GetAncestor(info.hwndFocus, GA_ROOT) == w))
+        return info.hwndFocus;
+    return w;
+}
 HKL windowLayout(HWND w)
 {
-    return GetKeyboardLayout(GetWindowThreadProcessId(w, nullptr));
+    HWND input = inputWindow(w);
+    return input ? GetKeyboardLayout(GetWindowThreadProcessId(input, nullptr)) : nullptr;
+}
+bool switchWindowLayout(HWND target, HKL layout, const std::function<bool()> &valid)
+{
+    HWND input = inputWindow(target);
+    auto unchanged = [&]
+    { return input && valid() && GetForegroundWindow() == target && inputWindow(target) == input; };
+    if (!layout || !unchanged())
+        return false;
+    if (windowLayout(target) == layout)
+        return true;
+    // Windows directs layout requests to the focused control, which can belong
+    // to a different UI thread/process than a Teams/WebView top-level window.
+    if (!PostMessageW(input, WM_INPUTLANGCHANGEREQUEST, 0, (LPARAM)layout))
+        return false;
+    for (int i = 0; i < 30; ++i)
+    {
+        if (!unchanged())
+            return false;
+        if (windowLayout(target) == layout)
+            return true;
+        // Some hosts handle this at their top level instead of the focused child.
+        if (i == 14 && input != target)
+            PostMessageW(target, WM_INPUTLANGCHANGEREQUEST, 0, (LPARAM)layout);
+        Sleep(10);
+    }
+    return unchanged() && windowLayout(target) == layout;
+}
+void showRequestedWindow(HWND window)
+{
+    ShowWindow(window, SW_SHOW);
+    // STARTF_USESHOWWINDOW can override the process's first ShowWindow with
+    // SW_HIDE. An explicit user request must still make the window visible.
+    if (!IsWindowVisible(window))
+        ShowWindow(window, SW_SHOW);
 }
 bool activateWindow(HWND window)
 {