Add new public APIs to find the z-order for links and widgets.

fpdfsdk/src/fpdfformfill.cpp

 // Copyright 2014 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 "../../public/fpdf_formfill.h"
 #include "../../public/fpdfview.h"
 #include "../../third_party/base/nonstd_unique_ptr.h"
 #include "../include/fsdk_define.h"
@@ skipping 16 matching lines @@
                                        FPDF_PAGE page) {
   if (!page)
     return nullptr;
 
   CPDFSDK_Document* pSDKDoc = FormHandleToSDKDoc(hHandle);
   return pSDKDoc ? pSDKDoc->GetPageView((CPDF_Page*)page, TRUE) : nullptr;
 }
 
 }  // namespace
 
-DLLEXPORT int STDCALL FPDPage_HasFormFieldAtPoint(FPDF_FORMHANDLE hHandle,
-                                                  FPDF_PAGE page,
-                                                  double page_x,
-                                                  double page_y) {
+DLLEXPORT int STDCALL FPDFPage_HasFormFieldAtPoint(FPDF_FORMHANDLE hHandle,
+                                                   FPDF_PAGE page,
+                                                   double page_x,
+                                                   double page_y) {
   if (!page || !hHandle)
     return -1;
+
   CPDF_Page* pPage = (CPDF_Page*)page;
-
-  nonstd::unique_ptr<CPDF_InterForm> pInterForm(
-      new CPDF_InterForm(pPage->m_pDocument, FALSE));
-  CPDF_FormControl* pFormCtrl =
-      pInterForm->GetControlAtPoint(pPage, (FX_FLOAT)page_x, (FX_FLOAT)page_y);
+  CPDF_InterForm interform(pPage->m_pDocument, FALSE);
+  CPDF_FormControl* pFormCtrl = interform.GetControlAtPoint(
+      pPage, (FX_FLOAT)page_x, (FX_FLOAT)page_y, nullptr);
   if (!pFormCtrl)
     return -1;
 
   CPDF_FormField* pFormField = pFormCtrl->GetField();
   if (!pFormField)
     return -1;
 
   return pFormField->GetFieldType();
 }
 
+DLLEXPORT int STDCALL FPDPage_HasFormFieldAtPoint(FPDF_FORMHANDLE hHandle,
+                                                  FPDF_PAGE page,
+                                                  double page_x,
+                                                  double page_y) {
+  return FPDFPage_HasFormFieldAtPoint(hHandle, page, page_x, page_y);
+}
+
+DLLEXPORT int STDCALL FPDFPage_FormFieldZOrderAtPoint(FPDF_FORMHANDLE hHandle,
+                                                      FPDF_PAGE page,
+                                                      double page_x,
+                                                      double page_y) {
+  if (!page || !hHandle)
+    return -1;
+
+  CPDF_Page* pPage = (CPDF_Page*)page;
+  CPDF_InterForm interform(pPage->m_pDocument, FALSE);
+  int z_order = -1;
+  (void)interform.GetControlAtPoint(pPage, (FX_FLOAT)page_x, (FX_FLOAT)page_y,
+                                    &z_order);
+  return z_order;
+}
+
 DLLEXPORT FPDF_FORMHANDLE STDCALL
 FPDFDOC_InitFormFillEnvironment(FPDF_DOCUMENT document,
                                 FPDF_FORMFILLINFO* formInfo) {
   if (!document || !formInfo || formInfo->version != 1)
     return nullptr;
 
   CPDF_Document* pDocument = (CPDF_Document*)document;
   CPDFDoc_Environment* pEnv = new CPDFDoc_Environment(pDocument, formInfo);
   pEnv->SetSDKDocument(new CPDFSDK_Document(pDocument, pEnv));
   return pEnv;
@@ skipping 252 matching lines @@
       }
     } else {
       bExistCAAction = aa.ActionExist(CPDF_AAction::ClosePage);
       if (bExistCAAction) {
         CPDF_Action action = aa.GetAction(CPDF_AAction::ClosePage);
         pActionHandler->DoAction_Page(action, CPDF_AAction::ClosePage, pSDKDoc);
       }
     }
   }
 }