Watch destruction of widgets around OnAAction() method.

We implemented the CFX_Observable mechanism for detecting
stale objects some time ago; now just use it in more places.

Change method signatures to required an ObservedPtr to
indicate that the callers are aware that the value may be
destroyed out from underneath them.

BUG=649659

Review-Url: https://codereview.chromium.org/2368403002

1 files changed, 17 insertions, 16 deletions

diff --git a/fpdfsdk/cpdfsdk_document.cpp b/fpdfsdk/cpdfsdk_document.cpp
index d4de6d0510..01e4d88ac1 100644
--- a/fpdfsdk/cpdfsdk_document.cpp
+++ b/fpdfsdk/cpdfsdk_document.cpp
@@ -31,7 +31,6 @@ CPDFSDK_Document* CPDFSDK_Document::FromFPDFFormHandle(
 CPDFSDK_Document::CPDFSDK_Document(UnderlyingDocumentType* pDoc,
                                    CPDFSDK_Environment* pEnv)
     : m_pDoc(pDoc),
-      m_pFocusAnnot(nullptr),
       m_pEnv(pEnv),
       m_bChangeMask(FALSE),
       m_bBeingDestroyed(FALSE) {}
@@ -174,14 +173,15 @@ void CPDFSDK_Document::UpdateAllViews(CPDFSDK_PageView* pSender,
 }
 
 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) {
@@ -189,24 +189,24 @@ FX_BOOL CPDFSDK_Document::SetFocusAnnot(CPDFSDK_Annot* pAnnot, uint32_t 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;
       }
     }
@@ -217,28 +217,29 @@ FX_BOOL CPDFSDK_Document::SetFocusAnnot(CPDFSDK_Annot* pAnnot, uint32_t nFlag) {
 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;