Watch destruction of widgets around OnAAction() method

fpdfsdk/cpdfsdk_document.cpp

 // 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
 
 #include "fpdfsdk/include/cpdfsdk_document.h"
 
 #include "core/fpdfapi/fpdf_parser/include/cpdf_array.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h"
@@ skipping 13 matching lines @@
 // static
 CPDFSDK_Document* CPDFSDK_Document::FromFPDFFormHandle(
     FPDF_FORMHANDLE hHandle) {
   CPDFSDK_Environment* pEnv = static_cast<CPDFSDK_Environment*>(hHandle);
   return pEnv ? pEnv->GetSDKDocument() : nullptr;
 }
 
 CPDFSDK_Document::CPDFSDK_Document(UnderlyingDocumentType* pDoc,
                                    CPDFSDK_Environment* pEnv)
     : m_pDoc(pDoc),
-      m_pFocusAnnot(nullptr),
       m_pEnv(pEnv),
       m_bChangeMask(FALSE),
       m_bBeingDestroyed(FALSE) {}
 
 CPDFSDK_Document::~CPDFSDK_Document() {
   m_bBeingDestroyed = TRUE;
 
   for (auto& it : m_pageMap)
     it.second->KillFocusAnnotIfNeeded();
 
@@ skipping 122 matching lines @@
                                       CPDFSDK_Annot* pAnnot) {
   for (const auto& it : m_pageMap) {
     CPDFSDK_PageView* pPageView = it.second;
     if (pPageView != pSender) {
       pPageView->UpdateView(pAnnot);
     }
   }
 }
 
 CPDFSDK_Annot* CPDFSDK_Document::GetFocusAnnot() {
-  return m_pFocusAnnot;
+  return m_pFocusAnnot.Get();
 }
 
-FX_BOOL CPDFSDK_Document::SetFocusAnnot(CPDFSDK_Annot* pAnnot, uint32_t nFlag) {
+FX_BOOL CPDFSDK_Document::SetFocusAnnot(CPDFSDK_Annot::ObservedPtr* pAnnot,
+                                        uint32_t nFlag) {
   if (m_bBeingDestroyed)
     return FALSE;
 
-  if (m_pFocusAnnot == pAnnot)
+  if (m_pFocusAnnot == *pAnnot)
     return TRUE;
 
   if (m_pFocusAnnot) {
     if (!KillFocusAnnot(nFlag))
       return FALSE;
   }
 
-  if (!pAnnot)
+  if (!*pAnnot)
     return FALSE;
 
 #ifdef PDF_ENABLE_XFA
-  CPDFSDK_Annot* pLastFocusAnnot = m_pFocusAnnot;
+  CPDFSDK_Annot::ObservedPtr pLastFocusAnnot(m_pFocusAnnot.Get());
 #endif  // PDF_ENABLE_XFA
-  CPDFSDK_PageView* pPageView = pAnnot->GetPageView();
+  CPDFSDK_PageView* pPageView = (*pAnnot)->GetPageView();
   if (pPageView && pPageView->IsValid()) {
     CPDFSDK_AnnotHandlerMgr* pAnnotHandler = m_pEnv->GetAnnotHandlerMgr();
     if (!m_pFocusAnnot) {
 #ifdef PDF_ENABLE_XFA
-      if (!pAnnotHandler->Annot_OnChangeFocus(pAnnot, pLastFocusAnnot))
+      if (!pAnnotHandler->Annot_OnChangeFocus(pAnnot, &pLastFocusAnnot))
         return FALSE;
 #endif  // PDF_ENABLE_XFA
       if (!pAnnotHandler->Annot_OnSetFocus(pAnnot, nFlag))
         return FALSE;
       if (!m_pFocusAnnot) {
-        m_pFocusAnnot = pAnnot;
+        m_pFocusAnnot.Reset(pAnnot->Get());
         return TRUE;
       }
     }
   }
   return FALSE;
 }
 
 FX_BOOL CPDFSDK_Document::KillFocusAnnot(uint32_t nFlag) {
   if (m_pFocusAnnot) {
     CPDFSDK_AnnotHandlerMgr* pAnnotHandler = m_pEnv->GetAnnotHandlerMgr();
-    CPDFSDK_Annot* pFocusAnnot = m_pFocusAnnot;
-    m_pFocusAnnot = nullptr;
+    CPDFSDK_Annot::ObservedPtr pFocusAnnot(m_pFocusAnnot.Get());
+    m_pFocusAnnot.Reset();
 
 #ifdef PDF_ENABLE_XFA
-    if (!pAnnotHandler->Annot_OnChangeFocus(nullptr, pFocusAnnot))
+    CPDFSDK_Annot::ObservedPtr pNull;
+    if (!pAnnotHandler->Annot_OnChangeFocus(&pNull, &pFocusAnnot))
       return FALSE;
 #endif  // PDF_ENABLE_XFA
 
-    if (pAnnotHandler->Annot_OnKillFocus(pFocusAnnot, nFlag)) {
+    if (pAnnotHandler->Annot_OnKillFocus(&pFocusAnnot, nFlag)) {
       if (pFocusAnnot->GetAnnotSubtype() == CPDF_Annot::Subtype::WIDGET) {
-        CPDFSDK_Widget* pWidget = (CPDFSDK_Widget*)pFocusAnnot;
+        CPDFSDK_Widget* pWidget =
+            static_cast<CPDFSDK_Widget*>(pFocusAnnot.Get());
         int nFieldType = pWidget->GetFieldType();
         if (FIELDTYPE_TEXTFIELD == nFieldType ||
             FIELDTYPE_COMBOBOX == nFieldType) {
           m_pEnv->OnSetFieldInputFocus(nullptr, 0, FALSE);
         }
       }
-
       if (!m_pFocusAnnot)
         return TRUE;
     } else {
-      m_pFocusAnnot = pFocusAnnot;
+      m_pFocusAnnot.Reset(pFocusAnnot.Get());
     }
   }
   return FALSE;
 }
 
 void CPDFSDK_Document::OnCloseDocument() {
   KillFocusAnnot();
 }
 
 FX_BOOL CPDFSDK_Document::GetPermissions(int nFlag) {
   return GetPDFDocument()->GetUserPermissions() & nFlag;
 }
 
 IJS_Runtime* CPDFSDK_Document::GetJsRuntime() {
   return m_pEnv->GetJSRuntime();
 }
 
 CFX_WideString CPDFSDK_Document::GetPath() {
   return m_pEnv->JS_docGetFilePath();
 }