From 5f83d0a3fac4f8ccef457c03b74433ffd7b12e2a Mon Sep 17 00:00:00 2001
From: Ashod Nakashian <ashod.nakashian@collabora.co.uk>
Date: Tue, 5 Jun 2018 11:28:30 +0200
Subject: [PATCH 02/14] svx: more accurate PDF text importing

---
 pdfium/fpdfsdk/fpdf_editpage.cpp | 84 ++++++++++++++++++++++++++++++++++++++++
 pdfium/public/fpdf_edit.h        | 36 +++++++++++++++++
 2 files changed, 120 insertions(+)

diff --git a/pdfium/fpdfsdk/fpdf_editpage.cpp b/pdfium/fpdfsdk/fpdf_editpage.cpp
index 912df63..3244943 100644
--- a/pdfium/fpdfsdk/fpdf_editpage.cpp
+++ b/pdfium/fpdfsdk/fpdf_editpage.cpp
@@ -12,6 +12,7 @@
 #include <vector>
 
 #include "core/fpdfapi/edit/cpdf_pagecontentgenerator.h"
+#include "core/fpdfapi/font/cpdf_font.h"
 #include "core/fpdfapi/page/cpdf_form.h"
 #include "core/fpdfapi/page/cpdf_formobject.h"
 #include "core/fpdfapi/page/cpdf_imageobject.h"
@@ -626,6 +627,26 @@ FPDFPageObj_SetLineCap(FPDF_PAGEOBJECT page_object, int line_cap) {
   return true;
 }
 
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFTextObj_CountChars(FPDF_PAGEOBJECT text_object)
+{
+  if (!text_object)
+    return 0;
+
+  CPDF_TextObject* pTxtObj = static_cast<CPDF_TextObject*>(text_object);
+  return pTxtObj->CountChars();
+}
+
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFTextObj_GetFontSize(FPDF_PAGEOBJECT text_object)
+{
+  if (!text_object)
+    return 0;
+
+  CPDF_TextObject* pTxtObj = static_cast<CPDF_TextObject*>(text_object);
+  return pTxtObj->GetFontSize();
+}
+
 FPDF_EXPORT void FPDF_CALLCONV
 FPDFTextObj_GetMatrix(FPDF_PAGEOBJECT text_object,
                       double* a,
@@ -642,3 +663,66 @@ FPDFTextObj_GetMatrix(FPDF_PAGEOBJECT text_object,
   *c = matrix.c;
   *d = matrix.d;
 }
+
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFTextObj_GetUnicode(FPDF_PAGEOBJECT text_object, int index)
+{
+  if (!text_object || index < 0)
+    return 0;
+
+  CPDF_TextObject* pTxtObj = static_cast<CPDF_TextObject*>(text_object);
+  if (index > pTxtObj->CountChars())
+    return 0;
+
+  CPDF_TextObjectItem info;
+  pTxtObj->GetCharInfo(index, &info);
+  return info.m_CharCode;
+}
+
+FPDF_EXPORT int FPDF_CALLCONV FPDFTextObj_GetText(FPDF_PAGEOBJECT text_object,
+                                                  int char_start,
+                                                  int char_count,
+                                                  unsigned short* result) {
+  if (!text_object || char_start < 0 || char_count < 0 || !result)
+    return 0;
+
+  CPDF_TextObject* pTxtObj = static_cast<CPDF_TextObject*>(text_object);
+  int char_available = pTxtObj->CountChars() - char_start;
+  if (char_available <= 0)
+    return 0;
+
+  char_count = std::min(char_count, char_available);
+  if (char_count == 0) {
+    // Writing out "", which has a character count of 1 due to the NUL.
+    *result = '\0';
+    return 1;
+  }
+
+  CPDF_Font* pFont = pTxtObj->GetFont();
+  WideString str;
+  for (uint32_t charcode : pTxtObj->GetCharCodes()) {
+    if (charcode != CPDF_Font::kInvalidCharCode)
+      str += pFont->UnicodeFromCharCode(charcode);
+  }
+
+//   CFX_WideTextBuf m_TextBuf;
+//   WideString str = textpage->GetPageText(char_start, char_count);
+//   return WideString(m_TextBuf.AsStringView().Mid(
+//       static_cast<size_t>(text_start), static_cast<size_t>(text_count)));
+
+//   if (str.GetLength() > static_cast<size_t>(char_count))
+//     str = str.Left(static_cast<size_t>(char_count));
+
+  // Reincode in UTF-16.
+//   WideString str = text.UTF8Decode();
+
+  // UFT16LE_Encode doesn't handle surrogate pairs properly, so it is expected
+  // the number of items to stay the same.
+  ByteString byte_str = str.UTF16LE_Encode();
+  size_t byte_str_len = byte_str.GetLength();
+  int ret_count = byte_str_len / sizeof(unsigned short);
+
+  ASSERT(ret_count <= char_count + 1);  // +1 to account for the NUL terminator.
+  memcpy(result, byte_str.GetBuffer(byte_str_len), byte_str_len);
+  return ret_count;
+}
diff --git a/pdfium/public/fpdf_edit.h b/pdfium/public/fpdf_edit.h
index 3f45495..602849f 100644
--- a/pdfium/public/fpdf_edit.h
+++ b/pdfium/public/fpdf_edit.h
@@ -971,6 +971,26 @@ FPDFPageObj_CreateTextObj(FPDF_DOCUMENT document,
                           FPDF_FONT font,
                           float font_size);
 
+// Get the number of characters from a text object.
+//
+// text_object - Handle of text object returned by FPDFPageObj_NewTextObj
+//               or FPDFPageObj_NewTextObjEx.
+// Return Value:
+// A character count in the text object.
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFTextObj_CountChars(FPDF_PAGEOBJECT text_object);
+
+
+// Get the font size of a text object.
+//
+// text_object - Handle of text object returned by FPDFPageObj_NewTextObj
+//               or FPDFPageObj_NewTextObjEx.
+//
+// Return Value:
+// The value of the font size
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFTextObj_GetFontSize(FPDF_PAGEOBJECT text_object);
+
 // Get the matrix of a particular text object.
 //
 // text_object - Handle of text object returned by FPDFPageObj_NewTextObj
@@ -986,6 +1006,22 @@ FPDFTextObj_GetMatrix(FPDF_PAGEOBJECT text_object,
                       double* c,
                       double* d);
 
+// Get the unicode of a special character in a text object.
+//
+// text_object - Handle of text object returned by FPDFPageObj_NewTextObj
+//               or FPDFPageObj_NewTextObjEx.
+// index - The index of the character to get the unicode.
+// Return Value:
+// The unicode value.
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFTextObj_GetUnicode(FPDF_PAGEOBJECT text_object, int index);
+
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFTextObj_GetText(FPDF_PAGEOBJECT text_object,
+                    int char_start,
+                    int char_count,
+                    unsigned short* result);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif  // __cplusplus
-- 
2.16.3