Get rid of NULLs in xfa/

xfa/fxfa/app/xfa_ffnotify.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/fxfa/app/xfa_ffnotify.h"
 
 #include "xfa/fxfa/app/xfa_ffbarcode.h"
 #include "xfa/fxfa/app/xfa_ffcheckbutton.h"
@@ skipping 204 matching lines @@
                                             XFA_EVENTTYPE eEventType,
                                             FX_BOOL bIsFormReady,
                                             FX_BOOL bRecursive,
                                             CXFA_WidgetAcc* pExclude) {
   CXFA_FFDocView* pDocView = m_pDoc->GetDocView();
   if (!pDocView) {
     return XFA_EVENTERROR_NotExist;
   }
   return pDocView->ExecEventActivityByDeepFirst(
       pFormNode, eEventType, bIsFormReady, bRecursive,
-      pExclude ? pExclude->GetNode() : NULL);
+      pExclude ? pExclude->GetNode() : nullptr);
 }
 void CXFA_FFNotify::AddCalcValidate(CXFA_Node* pNode) {
   CXFA_FFDocView* pDocView = m_pDoc->GetDocView();
   if (!pDocView) {
     return;
   }
   CXFA_WidgetAcc* pWidgetAcc =
       static_cast<CXFA_WidgetAcc*>(pNode->GetWidgetData());
   if (!pWidgetAcc) {
     return;
   }
   pDocView->AddCalculateWidgetAcc(pWidgetAcc);
   pDocView->AddValidateWidget(pWidgetAcc);
 }
 CXFA_FFDoc* CXFA_FFNotify::GetHDOC() {
   return m_pDoc;
 }
 IXFA_DocProvider* CXFA_FFNotify::GetDocProvider() {
   return m_pDoc->GetDocProvider();
 }
 IXFA_AppProvider* CXFA_FFNotify::GetAppProvider() {
   return m_pDoc->GetApp()->GetAppProvider();
 }
 CXFA_FFWidgetHandler* CXFA_FFNotify::GetWidgetHandler() {
   CXFA_FFDocView* pDocView = m_pDoc->GetDocView();
-  return pDocView ? pDocView->GetWidgetHandler() : NULL;
+  return pDocView ? pDocView->GetWidgetHandler() : nullptr;
 }
 CXFA_FFWidget* CXFA_FFNotify::GetHWidget(CXFA_LayoutItem* pLayoutItem) {
   return XFA_GetWidgetFromLayoutItem(pLayoutItem);
 }
 void CXFA_FFNotify::OpenDropDownList(CXFA_FFWidget* hWidget) {
   if (hWidget->GetDataAcc()->GetUIType() != XFA_ELEMENT_ChoiceList) {
     return;
   }
   CXFA_FFDocView* pDocView = m_pDoc->GetDocView();
   pDocView->LockUpdate();
@@ skipping 31 matching lines @@
 void CXFA_FFNotify::RunSubformIndexChange(CXFA_Node* pSubformNode) {
   CXFA_FFDocView* pDocView = m_pDoc->GetDocView();
   if (!pDocView) {
     return;
   }
   pDocView->AddIndexChangedSubform(pSubformNode);
 }
 CXFA_Node* CXFA_FFNotify::GetFocusWidgetNode() {
   CXFA_FFDocView* pDocView = m_pDoc->GetDocView();
   if (!pDocView) {
-    return NULL;
+    return nullptr;
   }
   CXFA_WidgetAcc* pAcc = pDocView->GetFocusWidgetAcc();
-  return pAcc ? pAcc->GetNode() : NULL;
+  return pAcc ? pAcc->GetNode() : nullptr;
 }
 void CXFA_FFNotify::SetFocusWidgetNode(CXFA_Node* pNode) {
   CXFA_FFDocView* pDocView = m_pDoc->GetDocView();
   if (!pDocView) {
     return;
   }
   CXFA_WidgetAcc* pAcc =
       pNode ? static_cast<CXFA_WidgetAcc*>(pNode->GetWidgetData()) : nullptr;
   pDocView->SetFocusWidgetAcc(pAcc);
 }
@@ skipping 189 matching lines @@
     return;
 
   CXFA_FFWidget* pWidget = XFA_GetWidgetFromLayoutItem(pSender);
   if (!pWidget)
     return;
 
   pDocView->DeleteLayoutItem(pWidget);
   m_pDoc->GetDocProvider()->WidgetPreRemove(pWidget, pWidget->GetDataAcc());
   pWidget->AddInvalidateRect(nullptr);
 }