Change IFWL_Widget to store a single delegate.

xfa/fxfa/app/xfa_ffchoicelist.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_ffchoicelist.h"
 
+#include "third_party/base/ptr_util.h"
 #include "xfa/fwl/core/cfwl_combobox.h"
 #include "xfa/fwl/core/cfwl_listbox.h"
 #include "xfa/fwl/core/fwl_noteimp.h"
 #include "xfa/fwl/core/ifwl_app.h"
 #include "xfa/fwl/core/ifwl_edit.h"
+#include "xfa/fxfa/app/cxfa_ffcomboboxdelegate.h"
+#include "xfa/fxfa/app/cxfa_fflistboxdelegate.h"
 #include "xfa/fxfa/app/xfa_fffield.h"
 #include "xfa/fxfa/app/xfa_fwladapter.h"
 #include "xfa/fxfa/cxfa_eventparam.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_FFListBox::CXFA_FFListBox(CXFA_FFPageView* pPageView,
                                CXFA_WidgetAcc* pDataAcc)
-    : CXFA_FFField(pPageView, pDataAcc), m_pOldDelegate(nullptr) {}
+    : CXFA_FFField(pPageView, pDataAcc) {}
 
 CXFA_FFListBox::~CXFA_FFListBox() {
   if (m_pNormalWidget) {
     IFWL_Widget* pWidget = m_pNormalWidget->GetWidget();
     CFWL_NoteDriver* pNoteDriver = pWidget->GetOwnerApp()->GetNoteDriver();
     pNoteDriver->UnregisterEventTarget(pWidget);
   }
 }
 
 FX_BOOL CXFA_FFListBox::LoadWidget() {
   CFWL_ListBox* pListBox = new CFWL_ListBox(GetFWLApp());
   pListBox->Initialize();
   pListBox->ModifyStyles(FWL_WGTSTYLE_VScroll | FWL_WGTSTYLE_NoBackground,
                          0xFFFFFFFF);
   m_pNormalWidget = (CFWL_Widget*)pListBox;
   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_FFListBoxDelegate>(
+      m_pNormalWidget->ReleaseDelegate(), this));
   m_pNormalWidget->LockUpdate();
 
   CFX_WideStringArray wsLabelArray;
   m_pDataAcc->GetChoiceListItems(wsLabelArray, FALSE);
   int32_t iItems = wsLabelArray.GetSize();
   for (int32_t i = 0; i < iItems; i++) {
     pListBox->AddString(wsLabelArray[i].AsStringC());
   }
   uint32_t dwExtendedStyle = FWL_STYLEEXT_LTB_ShowScrollBarFocus;
   if (m_pDataAcc->GetChoiceListOpen() == XFA_ATTRIBUTEENUM_MultiSelect) {
@@ skipping 120 matching lines @@
   if (nIndex < 0) {
     ((CFWL_ListBox*)m_pNormalWidget)->DeleteAll();
   } else {
     ((CFWL_ListBox*)m_pNormalWidget)
         ->DeleteString(((CFWL_ListBox*)m_pNormalWidget)->GetItem(nIndex));
   }
   m_pNormalWidget->Update();
   AddInvalidateRect();
 }
 
-void CXFA_FFListBox::OnProcessMessage(CFWL_Message* pMessage) {
-  m_pOldDelegate->OnProcessMessage(pMessage);
-}
-
-void CXFA_FFListBox::OnProcessEvent(CFWL_Event* pEvent) {
-  CXFA_FFField::OnProcessEvent(pEvent);
-  switch (pEvent->GetClassID()) {
-    case CFWL_EventType::SelectChanged: {
-      CFX_Int32Array arrSels;
-      OnSelectChanged(m_pNormalWidget->GetWidget(), arrSels);
-      break;
-    }
-    default:
-      break;
-  }
-  m_pOldDelegate->OnProcessEvent(pEvent);
-}
-void CXFA_FFListBox::OnDrawWidget(CFX_Graphics* pGraphics,
-                                  const CFX_Matrix* pMatrix) {
-  m_pOldDelegate->OnDrawWidget(pGraphics, pMatrix);
-}
-
 CXFA_FFComboBox::CXFA_FFComboBox(CXFA_FFPageView* pPageView,
                                  CXFA_WidgetAcc* pDataAcc)
-    : CXFA_FFField(pPageView, pDataAcc), m_pOldDelegate(nullptr) {}
+    : CXFA_FFField(pPageView, pDataAcc) {}
 
 CXFA_FFComboBox::~CXFA_FFComboBox() {}
 
 FX_BOOL CXFA_FFComboBox::GetBBox(CFX_RectF& rtBox,
                                  uint32_t dwStatus,
                                  FX_BOOL bDrawFocus) {
   if (bDrawFocus)
     return FALSE;
   return CXFA_FFWidget::GetBBox(rtBox, dwStatus);
 }
@@ skipping 12 matching lines @@
 FX_BOOL CXFA_FFComboBox::LoadWidget() {
   CFWL_ComboBox* pComboBox = new CFWL_ComboBox(GetFWLApp());
   pComboBox->Initialize();
   m_pNormalWidget = (CFWL_Widget*)pComboBox;
   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_FFComboBoxDelegate>(
+      m_pNormalWidget->ReleaseDelegate(), this));
   m_pNormalWidget->LockUpdate();
 
   CFX_WideStringArray wsLabelArray;
   m_pDataAcc->GetChoiceListItems(wsLabelArray, FALSE);
   int32_t iItems = wsLabelArray.GetSize();
   for (int32_t i = 0; i < iItems; i++) {
     pComboBox->AddString(wsLabelArray[i].AsStringC());
   }
   CFX_Int32Array iSelArray;
   m_pDataAcc->GetSelectedItems(iSelArray);
@@ skipping 240 matching lines @@
   eParam.m_eType = XFA_EVENT_PreOpen;
   eParam.m_pTarget = m_pDataAcc;
   m_pDataAcc->ProcessEvent(XFA_ATTRIBUTEENUM_PreOpen, &eParam);
 }
 void CXFA_FFComboBox::OnPostOpen(IFWL_Widget* pWidget) {
   CXFA_EventParam eParam;
   eParam.m_eType = XFA_EVENT_PostOpen;
   eParam.m_pTarget = m_pDataAcc;
   m_pDataAcc->ProcessEvent(XFA_ATTRIBUTEENUM_PostOpen, &eParam);
 }
-
-void CXFA_FFComboBox::OnProcessMessage(CFWL_Message* pMessage) {
-  m_pOldDelegate->OnProcessMessage(pMessage);
-}
-
-void CXFA_FFComboBox::OnProcessEvent(CFWL_Event* pEvent) {
-  CXFA_FFField::OnProcessEvent(pEvent);
-  switch (pEvent->GetClassID()) {
-    case CFWL_EventType::SelectChanged: {
-      CFWL_EvtCmbSelChanged* postEvent = (CFWL_EvtCmbSelChanged*)pEvent;
-      OnSelectChanged(m_pNormalWidget->GetWidget(), postEvent->iArraySels,
-                      postEvent->bLButtonUp);
-      break;
-    }
-    case CFWL_EventType::EditChanged: {
-      CFX_WideString wsChanged;
-      OnTextChanged(m_pNormalWidget->GetWidget(), wsChanged);
-      break;
-    }
-    case CFWL_EventType::PreDropDown: {
-      OnPreOpen(m_pNormalWidget->GetWidget());
-      break;
-    }
-    case CFWL_EventType::PostDropDown: {
-      OnPostOpen(m_pNormalWidget->GetWidget());
-      break;
-    }
-    default:
-      break;
-  }
-  m_pOldDelegate->OnProcessEvent(pEvent);
-}
-
-void CXFA_FFComboBox::OnDrawWidget(CFX_Graphics* pGraphics,
-                                   const CFX_Matrix* pMatrix) {
-  m_pOldDelegate->OnDrawWidget(pGraphics, pMatrix);
-}