Restore wine access after program loses and regains focus.

foreground_focus.cpp

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+#include "foreground_focus.h"
+#include "review_x11.h"
+
+namespace {
+struct Candidate {
+  HWND window = nullptr;
+  unsigned count = 0;
+};
+BOOL CALLBACK find_candidate(HWND window, LPARAM data) {
+  if (!IsWindowVisible(window) || !IsWindowEnabled(window) || IsIconic(window) ||
+      (GetWindowLongPtrW(window, GWL_EXSTYLE) & (WS_EX_TOOLWINDOW | WS_EX_NOACTIVATE)) ||
+      !GetPropW(window, L"__wine_x11_whole_window"))
+    return TRUE;
+  auto &candidate = *reinterpret_cast<Candidate *>(data);
+  candidate.window = window;
+  return ++candidate.count < 2;
+}
+}
+
+bool restore_virtual_desktop_focus() {
+  if (GetForegroundWindow() || !wine_x11_desktop_focused()) return false;
+  Candidate candidate;
+  EnumWindows(find_candidate, reinterpret_cast<LPARAM>(&candidate));
+  // Recheck focus after enumeration so a Linux/application transition cannot
+  // turn a recovery into activation of a background Wine application.
+  if (candidate.count != 1 || GetForegroundWindow() || !wine_x11_desktop_focused())
+    return false;
+  return wine_x11_restore_focus(candidate.window);
+}