From 2aa4b2f3928ccd8393f60db8f7b740c75f4e8a8d Mon Sep 17 00:00:00 2001
From: Tom Sepez <tsepez@chromium.org>
Date: Fri, 25 May 2018 22:38:49 +0000
Subject: Make CPDF_Page retainable.

Small step to reducing the differences between XFA and non-XFA. We
still use the RetainPtr pretty much as if it were an unique_ptr, in
that we're not yet caching pages and handing out multiple pointers
to the same page in the non-XFA case.

The one change is in page view cleanup, where we no longer need a
boolean and can take (sufficient) page ownership with a RetainPtr.

Tidy up some document.h -> page.h -> document.h circular inclusion
while we're at it.

NOTE: Wait for imminent branch to pass before landing. We'll want
this to bake a while.

Change-Id: I64a2f12ac3424ece1063d40583995b834117cf34
Reviewed-on: https://pdfium-review.googlesource.com/32790
Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
---
 fpdfsdk/fpdf_view.cpp | 49 +++++++++++++++++++++----------------------------
 1 file changed, 21 insertions(+), 28 deletions(-)

(limited to 'fpdfsdk/fpdf_view.cpp')

diff --git a/fpdfsdk/fpdf_view.cpp b/fpdfsdk/fpdf_view.cpp
index 6c4ad6020e..593a092fd3 100644
--- a/fpdfsdk/fpdf_view.cpp
+++ b/fpdfsdk/fpdf_view.cpp
@@ -355,9 +355,9 @@ FPDF_EXPORT FPDF_PAGE FPDF_CALLCONV FPDF_LoadPage(FPDF_DOCUMENT document,
   if (!pDict)
     return nullptr;
 
-  CPDF_Page* pPage = new CPDF_Page(pDoc, pDict, true);
+  auto pPage = pdfium::MakeRetain<CPDF_Page>(pDoc, pDict, true);
   pPage->ParseContent();
-  return FPDFPageFromUnderlying(pPage);
+  return FPDFPageFromUnderlying(pPage.Leak());
 #endif  // PDF_ENABLE_XFA
 }
 
@@ -723,35 +723,28 @@ FPDF_EXPORT FPDF_RECORDER FPDF_CALLCONV FPDF_RenderPageSkp(FPDF_PAGE page,
 #endif
 
 FPDF_EXPORT void FPDF_CALLCONV FPDF_ClosePage(FPDF_PAGE page) {
-  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   if (!page)
     return;
-#ifdef PDF_ENABLE_XFA
-  // Take it back across the API and throw it away.
-  RetainPtr<CPDFXFA_Page>().Unleak(pPage);
-#else   // PDF_ENABLE_XFA
+
+  // Take it back across the API and hold for duration of this function.
+  RetainPtr<UnderlyingPageType> pPage;
+  pPage.Unleak(UnderlyingFromFPDFPage(page));
+
+#ifndef PDF_ENABLE_XFA
   CPDFSDK_PageView* pPageView =
       static_cast<CPDFSDK_PageView*>(pPage->GetView());
-  if (pPageView) {
-    // We're already destroying the pageview, so bail early.
-    if (pPageView->IsBeingDestroyed())
-      return;
-
-    if (pPageView->IsLocked()) {
-      pPageView->TakePageOwnership();
-      return;
-    }
+  if (!pPageView || pPageView->IsBeingDestroyed())
+    return;
 
-    bool owned = pPageView->OwnsPage();
-    // This will delete the |pPageView| object. We must cleanup the PageView
-    // first because it will attempt to reset the View on the |pPage| during
-    // destruction.
-    pPageView->GetFormFillEnv()->RemovePageView(pPage);
-    // If the page was owned then the pageview will have deleted the page.
-    if (owned)
-      return;
+  if (pPageView->IsLocked()) {
+    pPageView->TakePageOwnership();
+    return;
   }
-  delete pPage;
+
+  // This will delete the |pPageView| object. We must cleanup the PageView
+  // first because it will attempt to reset the View on the |pPage| during
+  // destruction.
+  pPageView->GetFormFillEnv()->RemovePageView(pPage.Get());
 #endif  // PDF_ENABLE_XFA
 }
 
@@ -970,9 +963,9 @@ FPDF_EXPORT int FPDF_CALLCONV FPDF_GetPageSizeByIndex(FPDF_DOCUMENT document,
   if (!pDict)
     return false;
 
-  CPDF_Page page(pDoc, pDict, true);
-  *width = page.GetPageWidth();
-  *height = page.GetPageHeight();
+  auto page = pdfium::MakeRetain<CPDF_Page>(pDoc, pDict, true);
+  *width = page->GetPageWidth();
+  *height = page->GetPageHeight();
   return true;
 }
 
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