Add tablet heuristic detection

base/win/win_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/win/win_util.h"
 
 #include <aclapi.h>
 #include <shobjidl.h>  // Must be before propkey.
 #include <initguid.h>
 #include <propkey.h>
@@ skipping 196 matching lines @@
 }
 
 void SetShouldCrashOnProcessDetach(bool crash) {
   g_crash_on_process_detach = crash;
 }
 
 bool ShouldCrashOnProcessDetach() {
   return g_crash_on_process_detach;
 }
 
+bool IsMachineATablet() {
+  if (base::win::GetVersion() < base::win::VERSION_WIN7)
+    return false;
+  // TODO(ananta): Add keyboard detection logic if it can be made reliable.
+  const int kPenInput = NID_INTEGRATED_PEN | NID_EXTERNAL_PEN;
+  const int kMultiTouch = NID_INTEGRATED_TOUCH | NID_MULTI_INPUT | NID_READY;
+  int sm = GetSystemMetrics(SM_DIGITIZER);
+  return ((sm & kMultiTouch) == kMultiTouch) && ((sm & kPenInput) == 0);
+}
+
 }  // namespace win
 }  // namespace base
 
 #ifdef _MSC_VER
 //
 // If the ASSERT below fails, please install Visual Studio 2005 Service Pack 1.
 //
 extern char VisualStudio2005ServicePack1Detection[10];
 COMPILE_ASSERT(sizeof(&VisualStudio2005ServicePack1Detection) == sizeof(void*),
                VS2005SP1Detect);
 //
 // Chrome requires at least Service Pack 1 for Visual Studio 2005.
 //
 #endif  // _MSC_VER
 
 #ifndef COPY_FILE_COPY_SYMLINK
 #error You must install the Windows 2008 or Vista Software Development Kit and \
 set it as your default include path to build this library. You can grab it by \
 searching for "download windows sdk 2008" in your favorite web search engine.  \
 Also make sure you register the SDK with Visual Studio, by selecting \
 "Integrate Windows SDK with Visual Studio 2005" from the Windows SDK \
 menu (see Start - All Programs - Microsoft Windows SDK - \
 Visual Studio Registration).
 #endif