Trigger page view event when re-layout is finished

public/fpdf_formfill.h

 // 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
 
 #ifndef PUBLIC_FPDF_FORMFILL_H_
 #define PUBLIC_FPDF_FORMFILL_H_
 
 #include "fpdfview.h"
@@ skipping 802 matching lines @@
   **/
   void (*FFI_GetPageViewRect)(struct _FPDF_FORMFILLINFO* pThis,
                               FPDF_PAGE page,
                               double* left,
                               double* top,
                               double* right,
                               double* bottom);
 
   /**
   * Method: FFI_PageEvent
-  *     This method fires when pages have been added or deleted.
+  *     This method fires when pages have been added to or deleted from the XFA
+  *     document.
   * Interface Version:
   *     2
   * Implementation Required:
   *     yes
   * Parameters:
   *     pThis       -   Pointer to the interface structure itself.
-  *     page_index  -   0-based page number.
+  *     page_count  -   The number of pages to be added to or deleted from the
+  *                     document.
   *     event_type  -   See FXFA_PAGEVIEWEVENT_* above.
   * Return value:
   *       None.
+  * Comments:
+  *           The pages to be added or deleted always start from the last page
+  *           of document. This means that if parameter page_count is 2 and
+  *           event type is FXFA_PAGEVIEWEVENT_POSTADDED, 2 new pages have been
+  *           appended to the tail of document; If page_count is 2 and
+  *           event type is FXFA_PAGEVIEWEVENT_POSTREMOVED, the last 2 pages
+  *           have been deleted.
   **/
   void (*FFI_PageEvent)(struct _FPDF_FORMFILLINFO* pThis,
-                        int page_index,
+                        int page_count,
                         FPDF_DWORD event_type);
 
   /**
   * Method: FFI_PopupMenu
   *           This method will track the right context menu for XFA fields.
   * Interface Version:
   *           2
   * Implementation Required:
   *           yes
   * Parameters:
@@ skipping 856 matching lines @@
 FPDF_StringHandleAddString(FPDF_STRINGHANDLE stringHandle,
                            FPDF_BYTESTRING bsText,
                            FPDF_DWORD size);
 #endif  // PDF_ENABLE_XFA
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // PUBLIC_FPDF_FORMFILL_H_