Make FPDF_FormHandle be represented as an incomplete type.chromium/3510

Make consistent with other public API types.

Introduce CPDFSDKFormFillEnvironmentFromFPDFFormHandle() and
FPDFFormHandleFromCPDFSDKFormFillEnvironment() helper functions.
Use these to kill off some casts in the process.

Change-Id: I6230ecdb4cecd03076f5e24c8cc49c45ad694da7
Reviewed-on: https://pdfium-review.googlesource.com/39250
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

5 files changed, 33 insertions, 22 deletions

diff --git a/fpdfsdk/cpdfsdk_annotiterator_embeddertest.cpp b/fpdfsdk/cpdfsdk_annotiterator_embeddertest.cpp
index 879a365ae8..161ae95178 100644
--- a/fpdfsdk/cpdfsdk_annotiterator_embeddertest.cpp
+++ b/fpdfsdk/cpdfsdk_annotiterator_embeddertest.cpp
@@ -40,7 +40,7 @@ TEST_F(CPDFSDK_AnnotIteratorTest, CPDFSDK_AnnotIterator) {
   CFX_FloatRect RightTop(401, 401, 421, 421);
 
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      static_cast<CPDFSDK_FormFillEnvironment*>(form_handle());
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(form_handle());
 
   {
     // Page 0 specifies "row order".
diff --git a/fpdfsdk/cpdfsdk_helpers.h b/fpdfsdk/cpdfsdk_helpers.h
index 4fd85cfc72..5de947afdf 100644
--- a/fpdfsdk/cpdfsdk_helpers.h
+++ b/fpdfsdk/cpdfsdk_helpers.h
@@ -38,6 +38,7 @@ class CPDF_StructElement;
 class CPDF_StructTree;
 class CPDF_TextPage;
 class CPDF_TextPageFind;
+class CPDFSDK_FormFillEnvironment;
 class IPDFSDK_PauseAdapter;
 class FX_PATHPOINT;
 
@@ -197,6 +198,15 @@ inline CPDF_TextPageFind* CPDFTextPageFindFromFPDFSchHandle(
   return reinterpret_cast<CPDF_TextPageFind*>(handle);
 }
 
+inline FPDF_FORMHANDLE FPDFFormHandleFromCPDFSDKFormFillEnvironment(
+    CPDFSDK_FormFillEnvironment* handle) {
+  return reinterpret_cast<FPDF_FORMHANDLE>(handle);
+}
+inline CPDFSDK_FormFillEnvironment*
+CPDFSDKFormFillEnvironmentFromFPDFFormHandle(FPDF_FORMHANDLE handle) {
+  return reinterpret_cast<CPDFSDK_FormFillEnvironment*>(handle);
+}
+
 ByteString CFXByteStringFromFPDFWideString(FPDF_WIDESTRING wide_string);
 
 #ifdef PDF_ENABLE_XFA
diff --git a/fpdfsdk/fpdf_formfill.cpp b/fpdfsdk/fpdf_formfill.cpp
index d529a5be69..3a74bc3908 100644
--- a/fpdfsdk/fpdf_formfill.cpp
+++ b/fpdfsdk/fpdf_formfill.cpp
@@ -143,14 +143,9 @@ static_assert(kFormFieldTypeCount == FPDF_FORMFIELD_COUNT,
 
 namespace {
 
-CPDFSDK_FormFillEnvironment* HandleToCPDFSDKEnvironment(
-    FPDF_FORMHANDLE handle) {
-  return static_cast<CPDFSDK_FormFillEnvironment*>(handle);
-}
-
 CPDFSDK_InterForm* FormHandleToInterForm(FPDF_FORMHANDLE hHandle) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   return pFormFillEnv ? pFormFillEnv->GetInterForm() : nullptr;
 }
 
@@ -161,7 +156,7 @@ CPDFSDK_PageView* FormHandleToPageView(FPDF_FORMHANDLE hHandle,
     return nullptr;
 
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   return pFormFillEnv ? pFormFillEnv->GetPageView(pPage, true) : nullptr;
 }
 
@@ -326,8 +321,10 @@ FPDFDOC_InitFormFillEnvironment(FPDF_DOCUMENT document,
   // this and can just return the old Env. Otherwise, we'll end up setting a new
   // environment into the XFADocument and, that could get weird.
   auto* pContext = static_cast<CPDFXFA_Context*>(pDocument->GetExtension());
-  if (pContext && pContext->GetFormFillEnv())
-    return pContext->GetFormFillEnv();
+  if (pContext && pContext->GetFormFillEnv()) {
+    return FPDFFormHandleFromCPDFSDKFormFillEnvironment(
+        pContext->GetFormFillEnv());
+  }
 #endif
 
   auto pFormFillEnv = pdfium::MakeUnique<CPDFSDK_FormFillEnvironment>(
@@ -338,13 +335,14 @@ FPDFDOC_InitFormFillEnvironment(FPDF_DOCUMENT document,
     pContext->SetFormFillEnv(pFormFillEnv.get());
 #endif  // PDF_ENABLE_XFA
 
-  return pFormFillEnv.release();  // Caller takes ownership.
+  return FPDFFormHandleFromCPDFSDKFormFillEnvironment(
+      pFormFillEnv.release());  // Caller takes ownership.
 }
 
 FPDF_EXPORT void FPDF_CALLCONV
 FPDFDOC_ExitFormFillEnvironment(FPDF_FORMHANDLE hHandle) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (!pFormFillEnv)
     return;
 
@@ -363,7 +361,7 @@ FPDFDOC_ExitFormFillEnvironment(FPDF_FORMHANDLE hHandle) {
 FPDF_EXPORT void FPDF_CALLCONV FORM_SetSaveCallback(FPDF_FORMHANDLE hHandle,
                                                     FORM_SAVECALLED callback) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (!pFormFillEnv)
     return;
 
@@ -558,7 +556,7 @@ FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_Redo(FPDF_FORMHANDLE hHandle,
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
 FORM_ForceToKillFocus(FPDF_FORMHANDLE hHandle) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (!pFormFillEnv)
     return false;
   return pFormFillEnv->KillFocusAnnot(0);
@@ -632,7 +630,7 @@ FPDF_EXPORT void FPDF_CALLCONV FORM_OnAfterLoadPage(FPDF_PAGE page,
 FPDF_EXPORT void FPDF_CALLCONV FORM_OnBeforeClosePage(FPDF_PAGE page,
                                                       FPDF_FORMHANDLE hHandle) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (!pFormFillEnv)
     return;
 
@@ -651,7 +649,7 @@ FPDF_EXPORT void FPDF_CALLCONV FORM_OnBeforeClosePage(FPDF_PAGE page,
 FPDF_EXPORT void FPDF_CALLCONV
 FORM_DoDocumentJSAction(FPDF_FORMHANDLE hHandle) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (pFormFillEnv && pFormFillEnv->IsJSPlatformPresent())
     pFormFillEnv->ProcJavascriptFun();
 }
@@ -659,7 +657,7 @@ FORM_DoDocumentJSAction(FPDF_FORMHANDLE hHandle) {
 FPDF_EXPORT void FPDF_CALLCONV
 FORM_DoDocumentOpenAction(FPDF_FORMHANDLE hHandle) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (pFormFillEnv && pFormFillEnv->IsJSPlatformPresent())
     pFormFillEnv->ProcOpenAction();
 }
@@ -667,7 +665,7 @@ FORM_DoDocumentOpenAction(FPDF_FORMHANDLE hHandle) {
 FPDF_EXPORT void FPDF_CALLCONV FORM_DoDocumentAAction(FPDF_FORMHANDLE hHandle,
                                                       int aaType) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (!pFormFillEnv)
     return;
 
@@ -681,7 +679,8 @@ FPDF_EXPORT void FPDF_CALLCONV FORM_DoDocumentAAction(FPDF_FORMHANDLE hHandle,
   if (aa.ActionExist(type)) {
     CPDF_Action action = aa.GetAction(type);
     CPDFSDK_ActionHandler* pActionHandler =
-        HandleToCPDFSDKEnvironment(hHandle)->GetActionHandler();
+        CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle)
+            ->GetActionHandler();
     pActionHandler->DoAction_Document(action, type, pFormFillEnv);
   }
 }
@@ -690,7 +689,7 @@ FPDF_EXPORT void FPDF_CALLCONV FORM_DoPageAAction(FPDF_PAGE page,
                                                   FPDF_FORMHANDLE hHandle,
                                                   int aaType) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =
-      HandleToCPDFSDKEnvironment(hHandle);
+      CPDFSDKFormFillEnvironmentFromFPDFFormHandle(hHandle);
   if (!pFormFillEnv)
     return;
 
diff --git a/fpdfsdk/pwl/cpwl_combo_box_embeddertest.cpp b/fpdfsdk/pwl/cpwl_combo_box_embeddertest.cpp
index e4b329e61e..62d42f9344 100644
--- a/fpdfsdk/pwl/cpwl_combo_box_embeddertest.cpp
+++ b/fpdfsdk/pwl/cpwl_combo_box_embeddertest.cpp
@@ -29,7 +29,8 @@ class CPWLComboBoxEditEmbeddertest : public EmbedderTest {
     m_page = LoadPage(0);
     ASSERT_TRUE(m_page);
 
-    m_pFormFillEnv = static_cast<CPDFSDK_FormFillEnvironment*>(form_handle());
+    m_pFormFillEnv =
+        CPDFSDKFormFillEnvironmentFromFPDFFormHandle(form_handle());
     CPDFSDK_AnnotIterator iter(m_pFormFillEnv->GetPageView(0),
                                CPDF_Annot::Subtype::WIDGET);
 
diff --git a/fpdfsdk/pwl/cpwl_edit_embeddertest.cpp b/fpdfsdk/pwl/cpwl_edit_embeddertest.cpp
index 43d06d3d2a..3edbf7580a 100644
--- a/fpdfsdk/pwl/cpwl_edit_embeddertest.cpp
+++ b/fpdfsdk/pwl/cpwl_edit_embeddertest.cpp
@@ -28,7 +28,8 @@ class CPWLEditEmbeddertest : public EmbedderTest {
     m_page = LoadPage(0);
     ASSERT_TRUE(m_page);
 
-    m_pFormFillEnv = static_cast<CPDFSDK_FormFillEnvironment*>(form_handle());
+    m_pFormFillEnv =
+        CPDFSDKFormFillEnvironmentFromFPDFFormHandle(form_handle());
     CPDFSDK_AnnotIterator iter(m_pFormFillEnv->GetPageView(0),
                                CPDF_Annot::Subtype::WIDGET);
     // Normal text field.