Bug 672175 part.13 Compute cursor position at WM_MOUSEWHEEL and WM_MOUSEHWHEEL in MouseScrollHandler r=jimm

widget/windows/WinMouseScrollHandler.cpp

@@ -65,6 +65,8 @@ bool MouseScrollHandler::Device::Elantech::sUseSwipeHack = false;
 bool MouseScrollHandler::Device::Elantech::sUsePinchHack = false;
 DWORD MouseScrollHandler::Device::Elantech::sZoomUntil = 0;
 
+bool MouseScrollHandler::Device::SetPoint::sMightBeUsing = false;
+
 // The duration until timeout of events transaction.  The value is 1.5 sec,
 // it's just a magic number, it was suggested by Logitech's engineer, see
 // bug 605648 comment 90.
@@ -197,6 +199,26 @@ MouseScrollHandler::GetModifierKeyState(UINT aMessage)
   return result;
 }
 
+POINT
+MouseScrollHandler::ComputeMessagePos(UINT aMessage,
+                                      WPARAM aWParam,
+                                      LPARAM aLParam)
+{
+  POINT point;
+  if (Device::SetPoint::IsGetMessagePosResponseValid(aMessage,
+                                                     aWParam, aLParam)) {
+    PR_LOG(gMouseScrollLog, PR_LOG_ALWAYS,
+      ("MouseScroll::ComputeMessagePos: Using ::GetCursorPos()"));
+    ::GetCursorPos(&point);
+  } else {
+    DWORD dwPoints = ::GetMessagePos();
+    point.x = GET_X_LPARAM(dwPoints);
+    point.y = GET_Y_LPARAM(dwPoints);
+  }
+
+  return point;
+}
+
 MouseScrollHandler::ScrollTargetInfo
 MouseScrollHandler::GetScrollTargetInfo(
                       nsWindow* aWindow,
@@ -1151,5 +1173,51 @@ MouseScrollHandler::Device::UltraNav::IsObsoleteDriverInstalled()
   return majorVersion < 15 || majorVersion == 15 && minorVersion == 0;
 }
 
+/******************************************************************************
+ *
+ * Device::SetPoint
+ *
+ ******************************************************************************/
+
+/* static */
+bool
+MouseScrollHandler::Device::SetPoint::IsGetMessagePosResponseValid(
+                                        UINT aMessage,
+                                        WPARAM aWParam,
+                                        LPARAM aLParam)
+{
+  if (aMessage != WM_MOUSEHWHEEL) {
+    return false;
+  }
+
+  DWORD messagePos = ::GetMessagePos();
+
+  // XXX We should check whether SetPoint is installed or not by registry.
+
+  // SetPoint, Logitech (Logicool) mouse driver, (confirmed with 4.82.11 and
+  // MX-1100) always sets 0 to the lParam of WM_MOUSEHWHEEL.  The driver SENDs
+  // one message at first time, this time, ::GetMessagePos() works fine.
+  // Then, we will return 0 (0 means we process it) to the message. Then, the
+  // driver will POST the same messages continuously during the wheel tilted.
+  // But ::GetMessagePos() API always returns (0, 0) for them, even if the
+  // actual mouse cursor isn't 0,0.  Therefore, we cannot trust the result of
+  // ::GetMessagePos API if the sender is SetPoint.
+  if (!sMightBeUsing && !aLParam && (DWORD)aLParam != messagePos &&
+      ::InSendMessage()) {
+    sMightBeUsing = true;
+    PR_LOG(gMouseScrollLog, PR_LOG_ALWAYS,
+      ("MouseScroll::Device::SetPoint::IsGetMessagePosResponseValid(): "
+       "Might using SetPoint"));
+  } else if (sMightBeUsing && aLParam != 0 && ::InSendMessage()) {
+    // The user has changed the mouse from Logitech's to another one (e.g.,
+    // the user has changed to the touchpad of the notebook.
+    sMightBeUsing = false;
+    PR_LOG(gMouseScrollLog, PR_LOG_ALWAYS,
+      ("MouseScroll::Device::SetPoint::IsGetMessagePosResponseValid(): "
+       "Might stop using SetPoint"));
+  }
+  return (sMightBeUsing && !aLParam && !messagePos);
+}
+
 } // namespace widget
 } // namespace mozilla

widget/windows/WinMouseScrollHandler.h

@@ -35,6 +35,21 @@ public:
                              LRESULT *aRetValue,
                              bool &aEatMessage);
 
+  /**
+   * ComputeMessagePos() computes the cursor position when the message was
+   * added to the queue.
+   *
+   * @param aMessage    Handling message.
+   * @param aWParam     Handling message's wParam.
+   * @param aLParam     Handling message's lParam.
+   * @return            Mouse cursor position when the message is added to
+   *                    the queue or current cursor position if the result of
+   *                    ::GetMessagePos() is broken.
+   */
+  POINT ComputeMessagePos(UINT aMessage,
+                          WPARAM aWParam,
+                          LPARAM aLParam);
+
 private:
   MouseScrollHandler();
   ~MouseScrollHandler();
@@ -367,6 +382,20 @@ public:
       static bool IsObsoleteDriverInstalled();
     }; // class UltraNav
 
+    class SetPoint {
+    public:
+      /**
+       * SetPoint, Logitech's mouse driver, may report wrong cursor position
+       * for WM_MOUSEHWHEEL message.  See comment in the implementation for
+       * the detail.
+       */
+      static bool IsGetMessagePosResponseValid(UINT aMessage,
+                                               WPARAM aWParam,
+                                               LPARAM aLParam);
+    private:
+      static bool sMightBeUsing;
+    };
+
     static void Init();
 
     static bool IsFakeScrollableWindowNeeded()

widget/windows/nsWindow.cpp

@@ -7042,37 +7042,8 @@ nsWindow::OnMouseWheel(UINT aMsg, WPARAM aWParam, LPARAM aLParam,
 {
   *aRetValue = (aMsg != WM_MOUSEHWHEEL) ? TRUE : FALSE;
 
-  POINT point;
-  DWORD dwPoints = ::GetMessagePos();
-  point.x = GET_X_LPARAM(dwPoints);
-  point.y = GET_Y_LPARAM(dwPoints);
-
-  static bool sMayBeUsingLogitechMouse = false;
-  if (aMsg == WM_MOUSEHWHEEL) {
-    // Logitech (Logicool) mouse driver (confirmed with 4.82.11 and MX-1100)
-    // always sets 0 to the lParam of WM_MOUSEHWHEEL.  The driver SENDs one
-    // message at first time, this time, ::GetMessagePos works fine.
-    // Then, we will return 0 (0 means we process it) to the message. Then, the
-    // driver will POST the same messages continuously during the wheel tilted.
-    // But ::GetMessagePos API always returns (0, 0), even if the actual mouse
-    // cursor isn't 0,0.  Therefore, we cannot trust the result of
-    // ::GetMessagePos API if the sender is the driver.
-    if (!sMayBeUsingLogitechMouse && aLParam == 0 && (DWORD)aLParam != dwPoints &&
-        ::InSendMessage()) {
-      sMayBeUsingLogitechMouse = true;
-    } else if (sMayBeUsingLogitechMouse && aLParam != 0 && ::InSendMessage()) {
-      // The user has changed the mouse from Logitech's to another one (e.g.,
-      // the user has changed to the touchpad of the notebook.
-      sMayBeUsingLogitechMouse = false;
-    }
-    // If the WM_MOUSEHWHEEL comes from Logitech's mouse driver, and the
-    // ::GetMessagePos isn't correct, probably, we should use ::GetCursorPos
-    // instead.
-    if (sMayBeUsingLogitechMouse && aLParam == 0 && dwPoints == 0) {
-      ::GetCursorPos(&point);
-    }
-  }
-
+  MouseScrollHandler* handler = MouseScrollHandler::GetInstance();
+  POINT point = handler->ComputeMessagePos(aMsg, aWParam, aLParam);
   HWND underCursorWnd = ::WindowFromPoint(point);
   if (!underCursorWnd) {
     return;