Convert FWL_SCBCODE to an enum class

xfa/fwl/core/cfwl_event.h

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef XFA_FWL_CORE_CFWL_EVENT_H_
 #define XFA_FWL_CORE_CFWL_EVENT_H_
 
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
 #include "xfa/fwl/core/cfwl_message.h"
 #include "xfa/fwl/core/fwl_error.h"
 
+enum class FWL_SCBCODE {
+  None = 1,
+  Min,
+  Max,
+  PageBackward,
+  PageForward,
+  StepBackward,
+  StepForward,
+  Pos,
+  TrackPos,
+  EndScroll,
+};
+
 enum class CFWL_EventType {
   None = 0,
 
   CheckStateChanged,
   CheckWord,
   Click,
   Close,
   CloseUp,
   ContextMenu,
   DataSelected,
@@ skipping 104 matching lines @@
 
 FWL_EVENT_DEF(CFWL_EvtKillFocus,
               CFWL_EventType::KillFocus,
               IFWL_Widget* m_pKillFocus;)
 
 FWL_EVENT_DEF(CFWL_EvtDraw, CFWL_EventType::Draw, CFX_Graphics* m_pGraphics;
               IFWL_Widget * m_pWidget;)
 
 FWL_EVENT_DEF(CFWL_EvtClick, CFWL_EventType::Click)
 
-FWL_EVENT_DEF(CFWL_EvtScroll, CFWL_EventType::Scroll, uint32_t m_iScrollCode;
+FWL_EVENT_DEF(CFWL_EvtScroll, CFWL_EventType::Scroll, FWL_SCBCODE m_iScrollCode;
               FX_FLOAT m_fPos;
               bool* m_pRet;)
 
 FWL_EVENT_DEF(CFWL_EvtClose, CFWL_EventType::Close)
 
 FWL_EVENT_DEF(CFWL_EvtContextMenu,
               CFWL_EventType::ContextMenu,
               FX_FLOAT m_fPosX;
               FX_FLOAT m_fPosY;
               IFWL_Widget * m_pOwner;)
 
 FWL_EVENT_DEF(CFWL_EvtMenuCommand,
               CFWL_EventType::MenuCommand,
               int32_t m_iCommand;
               void* m_pData;)
 
 FWL_EVENT_DEF(CFWL_EvtSizeChanged,
               CFWL_EventType::SizeChanged,
               IFWL_Widget* m_pWidget;
               CFX_RectF m_rtOld;
               CFX_RectF m_rtNew;)
 
 FWL_EVENT_DEF(CFWL_EvtIdle, CFWL_EventType::Idle)
 
 #endif  // XFA_FWL_CORE_CFWL_EVENT_H_