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, 54 insertions, 53 deletions

diff --git a/fpdfsdk/cpdfsdk_pageview.cpp b/fpdfsdk/cpdfsdk_pageview.cpp
index 5989e29f64..900ea48670 100644
--- a/fpdfsdk/cpdfsdk_pageview.cpp
+++ b/fpdfsdk/cpdfsdk_pageview.cpp
@@ -29,7 +29,6 @@ CPDFSDK_PageView::CPDFSDK_PageView(CPDFSDK_Document* pSDKDoc,
                                    UnderlyingPageType* page)
     : m_page(page),
       m_pSDKDoc(pSDKDoc),
-      m_CaptureWidget(nullptr),
 #ifndef PDF_ENABLE_XFA
       m_bOwnsPage(false),
 #endif  // PDF_ENABLE_XFA
@@ -259,8 +258,8 @@ FX_BOOL CPDFSDK_PageView::DeleteAnnot(CPDFSDK_Annot* pAnnot) {
   auto it = std::find(m_fxAnnotArray.begin(), m_fxAnnotArray.end(), pAnnot);
   if (it != m_fxAnnotArray.end())
     m_fxAnnotArray.erase(it);
-  if (m_CaptureWidget == pAnnot)
-    m_CaptureWidget = nullptr;
+  if (m_pCaptureWidget.Get() == pAnnot)
+    m_pCaptureWidget.Reset();
 
   return TRUE;
 #else   // PDF_ENABLE_XFA
@@ -318,37 +317,40 @@ CPDFSDK_Annot* CPDFSDK_PageView::GetAnnotByXFAWidget(CXFA_FFWidget* hWidget) {
 
 FX_BOOL CPDFSDK_PageView::OnLButtonDown(const CFX_FloatPoint& point,
                                         uint32_t nFlag) {
-  CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
-  ASSERT(pEnv);
-  CPDFSDK_Annot* pFXAnnot = GetFXWidgetAtPoint(point.x, point.y);
-  if (!pFXAnnot) {
+  CPDFSDK_Annot::ObservedPtr pAnnot(GetFXWidgetAtPoint(point.x, point.y));
+  if (!pAnnot) {
     KillFocusAnnot(nFlag);
     return FALSE;
   }
 
+  CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
   CPDFSDK_AnnotHandlerMgr* pAnnotHandlerMgr = pEnv->GetAnnotHandlerMgr();
-  FX_BOOL bRet =
-      pAnnotHandlerMgr->Annot_OnLButtonDown(this, pFXAnnot, nFlag, point);
-  if (bRet)
-    SetFocusAnnot(pFXAnnot);
-  return bRet;
+  if (!pAnnotHandlerMgr->Annot_OnLButtonDown(this, &pAnnot, nFlag, point))
+    return FALSE;
+
+  if (!pAnnot)
+    return FALSE;
+
+  SetFocusAnnot(&pAnnot);
+  return TRUE;
 }
 
 #ifdef PDF_ENABLE_XFA
 FX_BOOL CPDFSDK_PageView::OnRButtonDown(const CFX_FloatPoint& point,
                                         uint32_t nFlag) {
+  CPDFSDK_Annot::ObservedPtr pAnnot(GetFXWidgetAtPoint(point.x, point.y));
+  if (!pAnnot)
+    return FALSE;
+
   CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
-  ASSERT(pEnv);
   CPDFSDK_AnnotHandlerMgr* pAnnotHandlerMgr = pEnv->GetAnnotHandlerMgr();
-  ASSERT(pAnnotHandlerMgr);
-
-  CPDFSDK_Annot* pFXAnnot = GetFXWidgetAtPoint(point.x, point.y);
-
-  if (!pFXAnnot)
+  FX_BOOL ok =
+      pAnnotHandlerMgr->Annot_OnRButtonDown(this, &pAnnot, nFlag, point);
+  if (!pAnnot)
     return FALSE;
 
-  if (pAnnotHandlerMgr->Annot_OnRButtonDown(this, pFXAnnot, nFlag, point))
-    SetFocusAnnot(pFXAnnot);
+  if (ok)
+    SetFocusAnnot(&pAnnot);
 
   return TRUE;
 }
@@ -356,16 +358,13 @@ FX_BOOL CPDFSDK_PageView::OnRButtonDown(const CFX_FloatPoint& point,
 FX_BOOL CPDFSDK_PageView::OnRButtonUp(const CFX_FloatPoint& point,
                                       uint32_t nFlag) {
   CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
-  ASSERT(pEnv);
   CPDFSDK_AnnotHandlerMgr* pAnnotHandlerMgr = pEnv->GetAnnotHandlerMgr();
-
-  CPDFSDK_Annot* pFXAnnot = GetFXWidgetAtPoint(point.x, point.y);
-
+  CPDFSDK_Annot::ObservedPtr pFXAnnot(GetFXWidgetAtPoint(point.x, point.y));
   if (!pFXAnnot)
     return FALSE;
 
-  if (pAnnotHandlerMgr->Annot_OnRButtonUp(this, pFXAnnot, nFlag, point))
-    SetFocusAnnot(pFXAnnot);
+  if (pAnnotHandlerMgr->Annot_OnRButtonUp(this, &pFXAnnot, nFlag, point))
+    SetFocusAnnot(&pFXAnnot);
 
   return TRUE;
 }
@@ -374,46 +373,45 @@ FX_BOOL CPDFSDK_PageView::OnRButtonUp(const CFX_FloatPoint& point,
 FX_BOOL CPDFSDK_PageView::OnLButtonUp(const CFX_FloatPoint& point,
                                       uint32_t nFlag) {
   CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
-  ASSERT(pEnv);
   CPDFSDK_AnnotHandlerMgr* pAnnotHandlerMgr = pEnv->GetAnnotHandlerMgr();
-  CPDFSDK_Annot* pFXAnnot = GetFXWidgetAtPoint(point.x, point.y);
-  CPDFSDK_Annot* pFocusAnnot = GetFocusAnnot();
-  FX_BOOL bRet = FALSE;
+  CPDFSDK_Annot::ObservedPtr pFXAnnot(GetFXWidgetAtPoint(point.x, point.y));
+  CPDFSDK_Annot::ObservedPtr pFocusAnnot(GetFocusAnnot());
   if (pFocusAnnot && pFocusAnnot != pFXAnnot) {
     // Last focus Annot gets a chance to handle the event.
-    bRet = pAnnotHandlerMgr->Annot_OnLButtonUp(this, pFocusAnnot, nFlag, point);
+    if (pAnnotHandlerMgr->Annot_OnLButtonUp(this, &pFocusAnnot, nFlag, point))
+      return TRUE;
   }
-  if (pFXAnnot && !bRet)
-    bRet = pAnnotHandlerMgr->Annot_OnLButtonUp(this, pFXAnnot, nFlag, point);
-  return bRet;
+  return pFXAnnot &&
+         pAnnotHandlerMgr->Annot_OnLButtonUp(this, &pFXAnnot, nFlag, point);
 }
 
 FX_BOOL CPDFSDK_PageView::OnMouseMove(const CFX_FloatPoint& point, int nFlag) {
   CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
   CPDFSDK_AnnotHandlerMgr* pAnnotHandlerMgr = pEnv->GetAnnotHandlerMgr();
-  if (CPDFSDK_Annot* pFXAnnot = GetFXAnnotAtPoint(point.x, point.y)) {
-    if (m_CaptureWidget && m_CaptureWidget != pFXAnnot) {
+  CPDFSDK_Annot::ObservedPtr pFXAnnot(GetFXAnnotAtPoint(point.x, point.y));
+  if (pFXAnnot) {
+    if (m_pCaptureWidget && m_pCaptureWidget != pFXAnnot) {
       m_bExitWidget = TRUE;
       m_bEnterWidget = FALSE;
-      pAnnotHandlerMgr->Annot_OnMouseExit(this, m_CaptureWidget, nFlag);
+      pAnnotHandlerMgr->Annot_OnMouseExit(this, &m_pCaptureWidget, nFlag);
     }
-    m_CaptureWidget = pFXAnnot;
+    m_pCaptureWidget.Reset(pFXAnnot.Get());
     m_bOnWidget = TRUE;
     if (!m_bEnterWidget) {
       m_bEnterWidget = TRUE;
       m_bExitWidget = FALSE;
-      pAnnotHandlerMgr->Annot_OnMouseEnter(this, pFXAnnot, nFlag);
+      pAnnotHandlerMgr->Annot_OnMouseEnter(this, &pFXAnnot, nFlag);
     }
-    pAnnotHandlerMgr->Annot_OnMouseMove(this, pFXAnnot, nFlag, point);
+    pAnnotHandlerMgr->Annot_OnMouseMove(this, &pFXAnnot, nFlag, point);
     return TRUE;
   }
   if (m_bOnWidget) {
     m_bOnWidget = FALSE;
     m_bExitWidget = TRUE;
     m_bEnterWidget = FALSE;
-    if (m_CaptureWidget) {
-      pAnnotHandlerMgr->Annot_OnMouseExit(this, m_CaptureWidget, nFlag);
-      m_CaptureWidget = nullptr;
+    if (m_pCaptureWidget) {
+      pAnnotHandlerMgr->Annot_OnMouseExit(this, &m_pCaptureWidget, nFlag);
+      m_pCaptureWidget.Reset();
     }
   }
   return FALSE;
@@ -423,13 +421,14 @@ FX_BOOL CPDFSDK_PageView::OnMouseWheel(double deltaX,
                                        double deltaY,
                                        const CFX_FloatPoint& point,
                                        int nFlag) {
-  if (CPDFSDK_Annot* pAnnot = GetFXWidgetAtPoint(point.x, point.y)) {
-    CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
-    CPDFSDK_AnnotHandlerMgr* pAnnotHandlerMgr = pEnv->GetAnnotHandlerMgr();
-    return pAnnotHandlerMgr->Annot_OnMouseWheel(this, pAnnot, nFlag,
-                                                (int)deltaY, point);
-  }
-  return FALSE;
+  CPDFSDK_Annot::ObservedPtr pAnnot(GetFXWidgetAtPoint(point.x, point.y));
+  if (!pAnnot)
+    return FALSE;
+
+  CPDFSDK_Environment* pEnv = m_pSDKDoc->GetEnv();
+  CPDFSDK_AnnotHandlerMgr* pAnnotHandlerMgr = pEnv->GetAnnotHandlerMgr();
+  return pAnnotHandlerMgr->Annot_OnMouseWheel(this, &pAnnot, nFlag, (int)deltaY,
+                                              point);
 }
 
 FX_BOOL CPDFSDK_PageView::OnChar(int nChar, uint32_t nFlag) {
@@ -511,9 +510,11 @@ void CPDFSDK_PageView::LoadFXAnnots() {
 
 void CPDFSDK_PageView::ClearFXAnnots() {
   SetLock(TRUE);
-  if (m_pSDKDoc && GetFocusAnnot())
-    m_pSDKDoc->SetFocusAnnot(nullptr);
-  m_CaptureWidget = nullptr;
+  if (m_pSDKDoc && GetFocusAnnot()) {
+    CPDFSDK_Annot::ObservedPtr pNull;
+    m_pSDKDoc->SetFocusAnnot(&pNull);
+  }
+  m_pCaptureWidget.Reset();
   for (CPDFSDK_Annot* pAnnot : m_fxAnnotArray)
     m_pSDKDoc->GetEnv()->GetAnnotHandlerMgr()->ReleaseAnnot(pAnnot);
   m_fxAnnotArray.clear();