Change IFWL_Widget to store a single delegate.

xfa/fxfa/app/xfa_ffcheckbutton.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_ffcheckbutton.h"
 
+#include "third_party/base/ptr_util.h"
 #include "xfa/fwl/core/cfwl_checkbox.h"
 #include "xfa/fwl/core/cfwl_message.h"
 #include "xfa/fwl/core/cfwl_widgetmgr.h"
 #include "xfa/fwl/core/fwl_noteimp.h"
+#include "xfa/fxfa/app/cxfa_ffcheckbuttondelegate.h"
 #include "xfa/fxfa/app/xfa_ffexclgroup.h"
 #include "xfa/fxfa/app/xfa_fffield.h"
 #include "xfa/fxfa/xfa_ffapp.h"
 #include "xfa/fxfa/xfa_ffdoc.h"
 #include "xfa/fxfa/xfa_ffdocview.h"
 #include "xfa/fxfa/xfa_ffpageview.h"
 #include "xfa/fxfa/xfa_ffwidget.h"
 
 CXFA_FFCheckButton::CXFA_FFCheckButton(CXFA_FFPageView* pPageView,
                                        CXFA_WidgetAcc* pDataAcc)
-    : CXFA_FFField(pPageView, pDataAcc), m_pOldDelegate(nullptr) {
+    : CXFA_FFField(pPageView, pDataAcc) {
   m_rtCheckBox.Set(0, 0, 0, 0);
 }
 
 CXFA_FFCheckButton::~CXFA_FFCheckButton() {}
 
 FX_BOOL CXFA_FFCheckButton::LoadWidget() {
   CFWL_CheckBox* pCheckBox = new CFWL_CheckBox(GetFWLApp());
   pCheckBox->Initialize();
   m_pNormalWidget = pCheckBox;
   m_pNormalWidget->SetLayoutItem(this);
 
   IFWL_Widget* pWidget = m_pNormalWidget->GetWidget();
   CFWL_NoteDriver* pNoteDriver = pWidget->GetOwnerApp()->GetNoteDriver();
   pNoteDriver->RegisterEventTarget(pWidget, pWidget);
 
-  m_pOldDelegate = m_pNormalWidget->GetCurrentDelegate();
-  m_pNormalWidget->SetCurrentDelegate(this);
+  m_pNormalWidget->SetDelegate(pdfium::MakeUnique<CXFA_FFCheckButtonDelegate>(
+      m_pNormalWidget->ReleaseDelegate(), this));
 
   if (m_pDataAcc->IsRadioButton())
     pCheckBox->ModifyStylesEx(FWL_STYLEEXT_CKB_RadioButton, 0xFFFFFFFF);
 
   m_pNormalWidget->LockUpdate();
   UpdateWidgetProperty();
   SetFWLCheckState(m_pDataAcc->GetCheckState());
   m_pNormalWidget->UnlockUpdate();
   return CXFA_FFField::LoadWidget();
 }
@@ skipping 237 matching lines @@
 }
 FX_BOOL CXFA_FFCheckButton::UpdateFWLData() {
   if (!m_pNormalWidget) {
     return FALSE;
   }
   XFA_CHECKSTATE eState = m_pDataAcc->GetCheckState();
   SetFWLCheckState(eState);
   m_pNormalWidget->Update();
   return TRUE;
 }
-
-void CXFA_FFCheckButton::OnProcessMessage(CFWL_Message* pMessage) {
-  m_pOldDelegate->OnProcessMessage(pMessage);
-}
-
-void CXFA_FFCheckButton::OnProcessEvent(CFWL_Event* pEvent) {
-  CXFA_FFField::OnProcessEvent(pEvent);
-  switch (pEvent->GetClassID()) {
-    case CFWL_EventType::CheckStateChanged: {
-      CXFA_EventParam eParam;
-      eParam.m_eType = XFA_EVENT_Change;
-      m_pDataAcc->GetValue(eParam.m_wsNewText, XFA_VALUEPICTURE_Raw);
-      CXFA_WidgetAcc* pFFExclGroup = m_pDataAcc->GetExclGroup();
-      if (ProcessCommittedData()) {
-        eParam.m_pTarget = pFFExclGroup;
-        if (pFFExclGroup) {
-          m_pDocView->AddValidateWidget(pFFExclGroup);
-          m_pDocView->AddCalculateWidgetAcc(pFFExclGroup);
-          pFFExclGroup->ProcessEvent(XFA_ATTRIBUTEENUM_Change, &eParam);
-        }
-        eParam.m_pTarget = m_pDataAcc;
-        m_pDataAcc->ProcessEvent(XFA_ATTRIBUTEENUM_Change, &eParam);
-      } else {
-        SetFWLCheckState(m_pDataAcc->GetCheckState());
-      }
-      if (pFFExclGroup) {
-        eParam.m_pTarget = pFFExclGroup;
-        pFFExclGroup->ProcessEvent(XFA_ATTRIBUTEENUM_Click, &eParam);
-      }
-      eParam.m_pTarget = m_pDataAcc;
-      m_pDataAcc->ProcessEvent(XFA_ATTRIBUTEENUM_Click, &eParam);
-      break;
-    }
-    default:
-      break;
-  }
-  m_pOldDelegate->OnProcessEvent(pEvent);
-}
-
-void CXFA_FFCheckButton::OnDrawWidget(CFX_Graphics* pGraphics,
-                                      const CFX_Matrix* pMatrix) {
-  m_pOldDelegate->OnDrawWidget(pGraphics, pMatrix);
-}