1 files changed, 112 insertions, 0 deletions
diff --git a/widget/windows/OSKTabTipManager.cpp b/widget/windows/OSKTabTipManager.cpp
new file mode 100644
index 0000000000..b7b06c08d1
--- /dev/null
+++ b/widget/windows/OSKTabTipManager.cpp
@@ -0,0 +1,112 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "OSKTabTipManager.h"
+
+#include "mozilla/Preferences.h"
+#include "nsDebug.h"
+#include "mozilla/widget/WinRegistry.h"
+
+#include <shellapi.h>
+#include <shlobj.h>
+#include <windows.h>
+
+namespace mozilla {
+namespace widget {
+
+/**
+ * Get the HWND for the on-screen keyboard, if it's up. Only
+ * allowed for Windows 8 and higher.
+ */
+static HWND GetOnScreenKeyboardWindow() {
+  const wchar_t kOSKClassName[] = L"IPTip_Main_Window";
+  HWND osk = ::FindWindowW(kOSKClassName, nullptr);
+  if (::IsWindow(osk) && ::IsWindowEnabled(osk) && ::IsWindowVisible(osk)) {
+    return osk;
+  }
+  return nullptr;
+}
+
+// static
+void OSKTabTipManager::ShowOnScreenKeyboard() {
+  const char* kOskPathPrefName = "ui.osk.on_screen_keyboard_path";
+
+  if (GetOnScreenKeyboardWindow()) {
+    return;
+  }
+
+  nsAutoString cachedPath;
+  nsresult result = Preferences::GetString(kOskPathPrefName, cachedPath);
+  if (NS_FAILED(result) || cachedPath.IsEmpty()) {
+    wchar_t path[MAX_PATH];
+    // The path to TabTip.exe is defined at the following registry key.
+    // This is pulled out of the 64-bit registry hive directly.
+    constexpr auto kRegKeyName =
+        u"Software\\Classes\\CLSID\\{054AAE20-4BEA-4347-8A35-64A533254A9D}\\LocalServer32"_ns;
+    if (!WinRegistry::GetString(HKEY_LOCAL_MACHINE, kRegKeyName, u""_ns, path,
+                                WinRegistry::kLegacyWinUtilsStringFlags)) {
+      return;
+    }
+
+    std::wstring wstrpath(path);
+    // The path provided by the registry will often contain
+    // %CommonProgramFiles%, which will need to be replaced if it is present.
+    size_t commonProgramFilesOffset = wstrpath.find(L"%CommonProgramFiles%");
+    if (commonProgramFilesOffset != std::wstring::npos) {
+      // The path read from the registry contains the %CommonProgramFiles%
+      // environment variable prefix. On 64 bit Windows the
+      // SHGetKnownFolderPath function returns the common program files path
+      // with the X86 suffix for the FOLDERID_ProgramFilesCommon value.
+      // To get the correct path to TabTip.exe we first read the environment
+      // variable CommonProgramW6432 which points to the desired common
+      // files path. Failing that we fallback to the SHGetKnownFolderPath API.
+      // We then replace the %CommonProgramFiles% value with the actual common
+      // files path found in the process.
+      std::wstring commonProgramFilesPath;
+      std::vector<wchar_t> commonProgramFilesPathW6432;
+      DWORD bufferSize =
+          ::GetEnvironmentVariableW(L"CommonProgramW6432", nullptr, 0);
+      if (bufferSize) {
+        commonProgramFilesPathW6432.resize(bufferSize);
+        ::GetEnvironmentVariableW(L"CommonProgramW6432",
+                                  commonProgramFilesPathW6432.data(),
+                                  bufferSize);
+        commonProgramFilesPath =
+            std::wstring(commonProgramFilesPathW6432.data());
+      } else {
+        PWSTR path = nullptr;
+        HRESULT hres = SHGetKnownFolderPath(FOLDERID_ProgramFilesCommon, 0,
+                                            nullptr, &path);
+        if (FAILED(hres) || !path) {
+          return;
+        }
+        commonProgramFilesPath =
+            static_cast<const wchar_t*>(nsDependentString(path).get());
+        ::CoTaskMemFree(path);
+      }
+      wstrpath.replace(commonProgramFilesOffset,
+                       wcslen(L"%CommonProgramFiles%"), commonProgramFilesPath);
+    }
+
+    cachedPath.Assign(wstrpath.data());
+    Preferences::SetString(kOskPathPrefName, cachedPath);
+  }
+
+  const char16_t* cachedPathPtr;
+  cachedPath.GetData(&cachedPathPtr);
+  ShellExecuteW(nullptr, L"", char16ptr_t(cachedPathPtr), nullptr, nullptr,
+                SW_SHOW);
+}
+
+// static
+void OSKTabTipManager::DismissOnScreenKeyboard() {
+  HWND osk = GetOnScreenKeyboardWindow();
+  if (osk) {
+    ::PostMessage(osk, WM_SYSCOMMAND, SC_CLOSE, 0);
+  }
+}
+
+}  // namespace widget
+}  // namespace mozilla