Identity the mouse pointer type from low-level events for Windows

ui/events/win/events_win.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 <stdint.h>
 #include <windowsx.h>
 
 #include "ui/events/event_constants.h"
 
 #include "base/logging.h"
 #include "base/time/time.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/keycodes/keyboard_code_conversion_win.h"
 #include "ui/events/win/system_event_state_lookup.h"
 #include "ui/gfx/geometry/point.h"
 
 namespace ui {
 
 namespace {
 
 // From MSDN: "Mouse" events are flagged with 0xFF515700 if they come
-// from a touch or stylus device.  In Vista or later, they are also flagged
-// with 0x80 if they come from touch.
-#define MOUSEEVENTF_FROMTOUCH (0xFF515700 | 0x80)
+// from a touch or stylus device.  In Vista or later, the eighth bit,
+// masked by 0x80, is used to differentiate touch input from pen input
+// (0 = pen, 1 = touch).
+#define MOUSEEVENTF_FROMTOUCHPEN 0xFF515700
+#define MOUSEEVENTF_FROMTOUCH (MOUSEEVENTF_FROMTOUCHPEN | 0x80)
+#define SIGNATURE_MASK 0xFFFFFF00
 
 // Get the native mouse key state from the native event message type.
 int GetNativeMouseKey(const base::NativeEvent& native_event) {
   switch (native_event.message) {
     case WM_LBUTTONDBLCLK:
     case WM_LBUTTONDOWN:
     case WM_LBUTTONUP:
     case WM_NCLBUTTONDBLCLK:
     case WM_NCLBUTTONDOWN:
     case WM_NCLBUTTONUP:
@@ skipping 250 matching lines @@
       return EF_RIGHT_MOUSE_BUTTON;
     // TODO: add support for MK_XBUTTON1.
     default:
       break;
   }
   return 0;
 }
 
 PointerDetails GetMousePointerDetailsFromNative(
     const base::NativeEvent& native_event) {
-  return PointerDetails(EventPointerType::POINTER_TYPE_MOUSE);
+  // We should filter out all the mouse events Synthesized from touch events.
+  // TODO(lanwei): Will set the pointer ID, see https://crbug.com/616771.
+  if ((GetMessageExtraInfo() & SIGNATURE_MASK) != MOUSEEVENTF_FROMTOUCHPEN)
+    return PointerDetails(EventPointerType::POINTER_TYPE_MOUSE);
+
+  return PointerDetails(EventPointerType::POINTER_TYPE_PEN);
 }
 
 gfx::Vector2d GetMouseWheelOffset(const base::NativeEvent& native_event) {
   DCHECK(native_event.message == WM_MOUSEWHEEL ||
          native_event.message == WM_MOUSEHWHEEL);
   if (native_event.message == WM_MOUSEWHEEL)
     return gfx::Vector2d(0, GET_WHEEL_DELTA_WPARAM(native_event.wParam));
   return gfx::Vector2d(GET_WHEEL_DELTA_WPARAM(native_event.wParam), 0);
 }
 
@@ skipping 99 matching lines @@
 }
 
 LPARAM GetLParamFromScanCode(uint16_t scan_code) {
   LPARAM l_param = static_cast<LPARAM>(scan_code & 0x00FF) << 16;
   if ((scan_code & 0xE000) == 0xE000)
     l_param |= (1 << 24);
   return l_param;
 }
 
 }  // namespace ui