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

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 945 matching lines @@
 #define FPDF_FORMFIELD_UNKNOWN 0      // Unknown.
 #define FPDF_FORMFIELD_PUSHBUTTON 1   // push button type.
 #define FPDF_FORMFIELD_CHECKBOX 2     // check box type.
 #define FPDF_FORMFIELD_RADIOBUTTON 3  // radio button type.
 #define FPDF_FORMFIELD_COMBOBOX 4     // combo box type.
 #define FPDF_FORMFIELD_LISTBOX 5      // list box type.
 #define FPDF_FORMFIELD_TEXTFIELD 6    // text field type.
 
 /**
  * Function: FPDPage_HasFormFieldAtPoint
- *          Check the form filed position by point.
+ *     Get the form field type by point.
  * Parameters:
- *          hHandle     -   Handle to the form fill module. Returned by
- *FPDFDOC_InitFormFillEnvironment.
- *          page        -   Handle to the page. Returned by FPDF_LoadPage
- *function.
- *          page_x      -   X position in PDF "user space".
- *          page_y      -   Y position in PDF "user space".
+ *     hHandle     -   Handle to the form fill module. Returned by
+ *                     FPDFDOC_InitFormFillEnvironment().
+ *     page        -   Handle to the page. Returned by FPDF_LoadPage().
+ *     page_x      -   X position in PDF "user space".
+ *     page_y      -   Y position in PDF "user space".
  * Return Value:
- *          Return the type of the formfiled; -1 indicates no fields.
+ *     Return the type of the form field; -1 indicates no field.
+ *     See field types above.
  **/
 DLLEXPORT int STDCALL FPDPage_HasFormFieldAtPoint(FPDF_FORMHANDLE hHandle,
                                                   FPDF_PAGE page,
                                                   double page_x,
                                                   double page_y);
 
 /**
+ * Function: FPDPage_FormFieldZOrderAtPoint
+ *     Get the form field z-order by point.
+ * Parameters:
+ *     hHandle     -   Handle to the form fill module. Returned by
+ *                     FPDFDOC_InitFormFillEnvironment().
+ *     page        -   Handle to the page. Returned by FPDF_LoadPage().
+ *     page_x      -   X position in PDF "user space".
+ *     page_y      -   Y position in PDF "user space".
+ * Return Value:
+ *     Return the z-order of the form field; -1 indicates no field.
+ **/
+DLLEXPORT int STDCALL FPDPage_FormFieldZOrderAtPoint(FPDF_FORMHANDLE hHandle,
+                                                     FPDF_PAGE page,
+                                                     double page_x,
+                                                     double page_y);
+
+/**
  * Function: FPDF_SetFormFieldHighlightColor
  *          Set the highlight color of specified or all the form fields in the
  *document.
  * Parameters:
  *          hHandle     -   Handle to the form fill module. Returned by
  *FPDFDOC_InitFormFillEnvironment.
  *          doc         -   Handle to the document. Returned by
  *FPDF_LoadDocument function.
  *          fieldType   -   A 32-bit integer indicating the type of a form
  *field(defined above).
@@ skipping 86 matching lines @@
                                     int size_x,
                                     int size_y,
                                     int rotate,
                                     int flags);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // PUBLIC_FPDF_FORMFILL_H_