Introduce WM_POINTER to Handle pointer events with pen type

ui/views/win/hwnd_message_handler.cc

Index: ui/views/win/hwnd_message_handler.cc
diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index 83ace04055ca90111db512fd9be52da95f213907..4984233e65c75a14e2c81ac2336c8f6cae75ec3e 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -18,7 +18,6 @@
 #include "base/macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
-#include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "base/win/scoped_gdi_object.h"
 #include "base/win/windows_version.h"
@@ -31,6 +30,7 @@
 #include "ui/display/win/dpi.h"
 #include "ui/display/win/screen_win.h"
 #include "ui/events/event.h"
+#include "ui/events/event_constants.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"
@@ -346,6 +346,7 @@ HWNDMessageHandler::HWNDMessageHandler(HWNDMessageHandlerDelegate* delegate)
       sent_window_size_changing_(false),
       left_button_down_on_caption_(false),
       background_fullscreen_hack_(false),
+      is_pointer_in_range_(false),
       autohide_factory_(this),
       weak_factory_(this) {}
 
@@ -942,6 +943,9 @@ LRESULT HWNDMessageHandler::HandleMouseMessage(unsigned int message,
                                                WPARAM w_param,
                                                LPARAM l_param,
                                                bool* handled) {
+  if (is_pointer_in_range_)

[ananta, 2017/03/09 00:37:33]

Does not appear to be set anywhere.

[lanwei, 2017/03/09 21:05:05]

It is not useful now, I deleted it.

+    return 0;
+
   // Don't track forwarded mouse messages. We expect the caller to track the
   // mouse.
   base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
@@ -974,6 +978,16 @@ LRESULT HWNDMessageHandler::HandleTouchMessage(unsigned int message,
   return ret;
 }
 
+LRESULT HWNDMessageHandler::HandlePointerMessage(unsigned int message,
+                                                 WPARAM w_param,
+                                                 LPARAM l_param,
+                                                 bool* handled) {
+  base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
+  LRESULT ret = OnPointerEvent(message, w_param, l_param);
+  *handled = IsMsgHandled();
+  return ret;
+}
+
 LRESULT HWNDMessageHandler::HandleScrollMessage(unsigned int message,
                                                 WPARAM w_param,
                                                 LPARAM l_param,
@@ -1642,6 +1656,85 @@ LRESULT HWNDMessageHandler::OnPointerActivate(UINT message,
   return -1;
 }
 
+LRESULT HWNDMessageHandler::OnPointerEvent(UINT message,
+                                           WPARAM w_param,
+                                           LPARAM l_param) {
+  UINT32 pointer_id = GET_POINTERID_WPARAM(w_param);
+  using GetPointerTypeFn = BOOL(WINAPI*)(UINT32, POINTER_INPUT_TYPE*);
+
+  POINTER_INPUT_TYPE pointer_type;
+  static GetPointerTypeFn get_pointer_type = reinterpret_cast<GetPointerTypeFn>(
+      GetProcAddress(GetModuleHandleA("user32.dll"), "GetPointerType"));
+  if (get_pointer_type && get_pointer_type(pointer_id, &pointer_type)) {

[ananta, 2017/03/09 00:37:33]

If we are getting a WM_POINTER*** message then we can assume Windows 8+ and
avoid these null checks here?

[lanwei, 2017/03/09 21:05:05]

You are right, but the other places calling the GetProcAddress also have the
null check, I think it maybe possible that the function call will fail even on
Windows 8+, and on Windows 7, someone may send WM_POINTER messages manually. 
https://msdn.microsoft.com/en-us/library/windows/desktop/ms683212(v=vs.85).aspx

+    if (pointer_type != PT_PEN) {
+      SetMsgHandled(FALSE);
+      return 0;
+    }
+
+    using GetPointerPenInfoFn = BOOL(WINAPI*)(UINT32, POINTER_PEN_INFO*);
+    using GetPointerInfoFn = BOOL(WINAPI*)(UINT32, POINTER_INFO*);
+
+    POINTER_INFO pointer_info;
+    static GetPointerInfoFn get_pointer_info =
+        reinterpret_cast<GetPointerInfoFn>(
+            GetProcAddress(GetModuleHandleA("user32.dll"), "GetPointerInfo"));
+
+    POINTER_PEN_INFO pointer_pen_info;
+    static GetPointerPenInfoFn get_pointer_pen_info =
+        reinterpret_cast<GetPointerPenInfoFn>(GetProcAddress(
+            GetModuleHandleA("user32.dll"), "GetPointerPenInfo"));
+    if (get_pointer_pen_info &&
+        GetPointerPenInfo(pointer_id, &pointer_pen_info)) {
+      float pressure = (float)pointer_pen_info.pressure / 1024;
+      float rotation = pointer_pen_info.rotation;
+      int tiltX = pointer_pen_info.tiltX;
+      int tiltY = pointer_pen_info.tiltY;
+      gfx::Point point;
+      if (get_pointer_info && get_pointer_info(pointer_id, &pointer_info)) {
+        POINT client_point = pointer_info.ptPixelLocation;
+        ScreenToClient(hwnd(), &client_point);
+        point = gfx::Point(client_point.x, client_point.y);
+      }
+      ui::EventType event_type = ui::ET_MOUSE_MOVED;

[ananta, 2017/03/09 00:37:33]

Please add some comments here. The code below is creating a fake mouse message
from the pointer event and then setting up an associated pointer details
structure in the MouseEvent structure. 

Once we have that, does everything else automatically work? 

[lanwei, 2017/03/09 21:05:05]

Yes. Touch and mouse work as before, and we are receiving stylus information
through WM_POINTER messages.

+      int flag = 0;
+      switch (message) {
+        case WM_POINTERDOWN:
+          event_type = ui::ET_MOUSE_PRESSED;
+          flag = ui::EF_LEFT_MOUSE_BUTTON;
+          break;
+        case WM_POINTERUP:
+          event_type = ui::ET_MOUSE_RELEASED;
+          flag = ui::EF_LEFT_MOUSE_BUTTON;
+          break;
+        case WM_POINTERUPDATE:
+          event_type = ui::ET_MOUSE_MOVED;
+          break;
+        case WM_POINTERLEAVE:
+          event_type = ui::ET_MOUSE_EXITED;
+          break;
+        default:
+          break;
+      }
+      ui::MouseEvent event(event_type, point, point, base::TimeTicks::Now(), 0,
+                           0);
+      event.set_flags(flag);
+      ui::PointerDetails pointer_details(ui::EventPointerType::POINTER_TYPE_PEN,
+                                         0.0f, 0.0f, pressure, tiltX, tiltY,
+                                         0.0f, rotation, pointer_id);
+      event.set_pointer_details(pointer_details);
+
+      // There are cases where the code handling the message destroys the
+      // window, so use the weak ptr to check if destruction occured or not.
+      base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
+      bool handled = delegate_->HandleMouseEvent(event);
+
+      if (ref.get())
+        SetMsgHandled(handled);
+    }
+  }
+  return 0;
+}
+
 void HWNDMessageHandler::OnMove(const gfx::Point& point) {
   delegate_->HandleMove();
   SetMsgHandled(FALSE);
@@ -2168,13 +2261,6 @@ void HWNDMessageHandler::OnThemeChanged() {
   ui::NativeThemeWin::CloseHandles();
 }
 
-void HWNDMessageHandler::OnTimeChange() {
-  // Call NowFromSystemTime() to force base::Time to re-initialize the clock
-  // from system time. Otherwise base::Time::Now() might continue to reflect the
-  // old system clock for some amount of time. See https://crbug.com/672906#c5
-  base::Time::NowFromSystemTime();
-}
-
 LRESULT HWNDMessageHandler::OnTouchEvent(UINT message,
                                          WPARAM w_param,
                                          LPARAM l_param) {