IFWL cleanup in the Combo classes

xfa/fwl/core/cfwl_listbox.cpp

 // Copyright 2014 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
 
 #include "xfa/fwl/core/cfwl_listbox.h"
 
 #include <memory>
 
@@ skipping 83 matching lines @@
 void CFWL_ListBox::GetItemText(CFWL_ListItem* pItem, CFX_WideString& wsText) {
   if (GetWidget())
     ToListBox(GetWidget())->GetItemText(pItem, wsText);
 }
 
 void CFWL_ListBox::GetScrollPos(FX_FLOAT& fPos, bool bVert) {
   if (GetWidget())
     ToListBox(GetWidget())->GetScrollPos(fPos, bVert);
 }
 
-int32_t CFWL_ListBox::CountItems() {
+int32_t CFWL_ListBox::CountItems() const {
   return pdfium::CollectionSize<int32_t>(m_ItemArray);
 }
 
 CFWL_ListItem* CFWL_ListBox::GetItem(int32_t nIndex) {
   if (nIndex < 0 || nIndex >= CountItems())
     return nullptr;
 
   return m_ItemArray[nIndex].get();
 }
 
 uint32_t CFWL_ListBox::GetItemStates(CFWL_ListItem* pItem) {
   if (!pItem)
     return 0;
   CFWL_ListItem* pListItem = static_cast<CFWL_ListItem*>(pItem);
   return pListItem->m_dwStates | pListItem->m_dwCheckState;
 }
 
 void CFWL_ListBox::GetCaption(IFWL_Widget* pWidget, CFX_WideString& wsCaption) {
   wsCaption = L"";
 }
 
-int32_t CFWL_ListBox::CountItems(const IFWL_Widget* pWidget) {
+int32_t CFWL_ListBox::CountItems(const IFWL_Widget* pWidget) const {
   return pdfium::CollectionSize<int32_t>(m_ItemArray);
 }
 
 CFWL_ListItem* CFWL_ListBox::GetItem(const IFWL_Widget* pWidget,
-                                     int32_t nIndex) {
+                                     int32_t nIndex) const {
   if (nIndex < 0 || nIndex >= CountItems(pWidget))
     return nullptr;
 
   return m_ItemArray[nIndex].get();
 }
 
 int32_t CFWL_ListBox::GetItemIndex(IFWL_Widget* pWidget, CFWL_ListItem* pItem) {
   auto it = std::find_if(
       m_ItemArray.begin(), m_ItemArray.end(),
       [pItem](const std::unique_ptr<CFWL_ListItem>& candidate) {
@@ skipping 81 matching lines @@
 uint32_t CFWL_ListBox::GetItemCheckState(IFWL_Widget* pWidget,
                                          CFWL_ListItem* pItem) {
   return static_cast<CFWL_ListItem*>(pItem)->m_dwCheckState;
 }
 
 void CFWL_ListBox::SetItemCheckState(IFWL_Widget* pWidget,
                                      CFWL_ListItem* pItem,
                                      uint32_t dwCheckState) {
   static_cast<CFWL_ListItem*>(pItem)->m_dwCheckState = dwCheckState;
 }