Use Byte/WideString iterators

Change-Id: I85c8423c177fd7ecd5da90ef89419efc0f9cf44b
Reviewed-on: https://pdfium-review.googlesource.com/4262
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

16 files changed, 53 insertions, 101 deletions

diff --git a/core/fxcrt/fx_bidi.cpp b/core/fxcrt/fx_bidi.cpp
index 5ad6439e07..49333f6a76 100644
--- a/core/fxcrt/fx_bidi.cpp
+++ b/core/fxcrt/fx_bidi.cpp
@@ -52,8 +52,8 @@ CFX_BidiString::CFX_BidiString(const CFX_WideString& str)
     : m_Str(str),
       m_pBidiChar(new CFX_BidiChar),
       m_eOverallDirection(CFX_BidiChar::LEFT) {
-  for (int i = 0; i < m_Str.GetLength(); ++i) {
-    if (m_pBidiChar->AppendChar(m_Str.GetAt(i)))
+  for (const auto& c : m_Str) {
+    if (m_pBidiChar->AppendChar(c))
       m_Order.push_back(m_pBidiChar->GetSegmentInfo());
   }
   if (m_pBidiChar->EndChar())
diff --git a/core/fxcrt/fx_extension.cpp b/core/fxcrt/fx_extension.cpp
index acdce048e0..f3e72fd6df 100644
--- a/core/fxcrt/fx_extension.cpp
+++ b/core/fxcrt/fx_extension.cpp
@@ -509,11 +509,11 @@ int32_t FXSYS_strnicmp(const char* s1, const char* s2, size_t count) {
 uint32_t FX_HashCode_GetA(const CFX_ByteStringC& str, bool bIgnoreCase) {
   uint32_t dwHashCode = 0;
   if (bIgnoreCase) {
-    for (FX_STRSIZE i = 0; i < str.GetLength(); ++i)
-      dwHashCode = 31 * dwHashCode + FXSYS_tolower(str.CharAt(i));
+    for (const auto& c : str)
+      dwHashCode = 31 * dwHashCode + FXSYS_tolower(c);
   } else {
-    for (FX_STRSIZE i = 0; i < str.GetLength(); ++i)
-      dwHashCode = 31 * dwHashCode + str.CharAt(i);
+    for (const auto& c : str)
+      dwHashCode = 31 * dwHashCode + c;
   }
   return dwHashCode;
 }
@@ -521,11 +521,11 @@ uint32_t FX_HashCode_GetA(const CFX_ByteStringC& str, bool bIgnoreCase) {
 uint32_t FX_HashCode_GetW(const CFX_WideStringC& str, bool bIgnoreCase) {
   uint32_t dwHashCode = 0;
   if (bIgnoreCase) {
-    for (FX_STRSIZE i = 0; i < str.GetLength(); ++i)
-      dwHashCode = 1313 * dwHashCode + FXSYS_tolower(str.CharAt(i));
+    for (const auto& c : str)
+      dwHashCode = 1313 * dwHashCode + FXSYS_tolower(c);
   } else {
-    for (FX_STRSIZE i = 0; i < str.GetLength(); ++i)
-      dwHashCode = 1313 * dwHashCode + str.CharAt(i);
+    for (const auto& c : str)
+      dwHashCode = 1313 * dwHashCode + c;
   }
   return dwHashCode;
 }
diff --git a/core/fxge/ge/cfx_fontmapper.cpp b/core/fxge/ge/cfx_fontmapper.cpp
index 0cff344599..ff80685d96 100644
--- a/core/fxge/ge/cfx_fontmapper.cpp
+++ b/core/fxge/ge/cfx_fontmapper.cpp
@@ -6,6 +6,7 @@
 
 #include "core/fxge/cfx_fontmapper.h"
 
+#include <algorithm>
 #include <memory>
 #include <utility>
 #include <vector>
@@ -326,14 +327,9 @@ void CFX_FontMapper::AddInstalledFont(const CFX_ByteString& name, int charset) {
   if (name == m_LastFamily)
     return;
 
-  const uint8_t* ptr = name.raw_str();
-  bool bLocalized = false;
-  for (int i = 0; i < name.GetLength(); i++) {
-    if (ptr[i] > 0x80) {
-      bLocalized = true;
-      break;
-    }
-  }
+  bool bLocalized = std::any_of(name.begin(), name.end(), [](const char& c) {
+    return static_cast<uint8_t>(c) > 0x80;
+  });
 
   if (bLocalized) {
     void* hFont = m_pFontInfo->GetFont(name.c_str());
diff --git a/fpdfsdk/cpdfsdk_widget.cpp b/fpdfsdk/cpdfsdk_widget.cpp
index 5f0bf1dc17..a1cd8c7ce4 100644
--- a/fpdfsdk/cpdfsdk_widget.cpp
+++ b/fpdfsdk/cpdfsdk_widget.cpp
@@ -249,10 +249,10 @@ bool CPDFSDK_Widget::OnXFAAAction(PDFSDK_XFAAActionType eXFAAAT,
   if (data.nSelEnd > data.nSelStart)
     param.m_wsNewText.Delete(data.nSelStart, data.nSelEnd - data.nSelStart);
 
-  for (int i = 0; i < data.sChange.GetLength(); i++)
-    param.m_wsNewText.Insert(data.nSelStart, data.sChange[i]);
-  param.m_wsPrevText = data.sValue;
+  for (const auto& c : data.sChange)
+    param.m_wsNewText.Insert(data.nSelStart, c);
 
+  param.m_wsPrevText = data.sValue;
   if ((eEventType == XFA_EVENT_Click || eEventType == XFA_EVENT_Change) &&
       GetFieldType() == FIELDTYPE_RADIOBUTTON) {
     if (CXFA_FFWidget* hGroupWidget = GetGroupMixXFAWidget()) {
diff --git a/fpdfsdk/javascript/PublicMethods.cpp b/fpdfsdk/javascript/PublicMethods.cpp
index f479527ef6..b5d4f7ba55 100644
--- a/fpdfsdk/javascript/PublicMethods.cpp
+++ b/fpdfsdk/javascript/PublicMethods.cpp
@@ -1141,8 +1141,7 @@ bool CJS_PublicMethods::AFDate_FormatEx(CJS_Runtime* pRuntime,
 double CJS_PublicMethods::MakeInterDate(const CFX_WideString& strValue) {
   std::vector<CFX_WideString> wsArray;
   CFX_WideString sTemp = L"";
-  for (int i = 0; i < strValue.GetLength(); ++i) {
-    wchar_t c = strValue.GetAt(i);
+  for (const auto& c : strValue) {
     if (c == L' ' || c == L':') {
       wsArray.push_back(sTemp);
       sTemp = L"";
@@ -1775,22 +1774,17 @@ bool CJS_PublicMethods::AFExtractNums(CJS_Runtime* pRuntime,
   CFX_WideString sPart;
   CJS_Array nums;
   int nIndex = 0;
-  for (int i = 0, sz = str.GetLength(); i < sz; i++) {
-    wchar_t wc = str.GetAt(i);
+  for (const auto& wc : str) {
     if (FXSYS_iswdigit(wc)) {
       sPart += wc;
-    } else {
-      if (sPart.GetLength() > 0) {
-        nums.SetElement(pRuntime, nIndex, CJS_Value(pRuntime, sPart.c_str()));
-        sPart = L"";
-        nIndex++;
-      }
+    } else if (sPart.GetLength() > 0) {
+      nums.SetElement(pRuntime, nIndex, CJS_Value(pRuntime, sPart.c_str()));
+      sPart = L"";
+      nIndex++;
     }
   }
-
-  if (sPart.GetLength() > 0) {
+  if (sPart.GetLength() > 0)
     nums.SetElement(pRuntime, nIndex, CJS_Value(pRuntime, sPart.c_str()));
-  }
 
   if (nums.GetLength(pRuntime) > 0)
     vRet = CJS_Value(pRuntime, nums);
diff --git a/fpdfsdk/javascript/app.cpp b/fpdfsdk/javascript/app.cpp
index 400340e38d..6d31d7e2e4 100644
--- a/fpdfsdk/javascript/app.cpp
+++ b/fpdfsdk/javascript/app.cpp
@@ -696,19 +696,10 @@ bool app::browseForDoc(CJS_Runtime* pRuntime,
 
 CFX_WideString app::SysPathToPDFPath(const CFX_WideString& sOldPath) {
   CFX_WideString sRet = L"/";
-
-  for (int i = 0, sz = sOldPath.GetLength(); i < sz; i++) {
-    wchar_t c = sOldPath.GetAt(i);
-    if (c == L':') {
-    } else {
-      if (c == L'\\') {
-        sRet += L"/";
-      } else {
-        sRet += c;
-      }
-    }
+  for (const wchar_t& c : sOldPath) {
+    if (c != L':')
+      sRet += (c == L'\\') ? L'/' : c;
   }
-
   return sRet;
 }
 
diff --git a/fxbarcode/BC_UtilCodingConvert.cpp b/fxbarcode/BC_UtilCodingConvert.cpp
index f1dea885c3..f0f497a07b 100644
--- a/fxbarcode/BC_UtilCodingConvert.cpp
+++ b/fxbarcode/BC_UtilCodingConvert.cpp
@@ -25,9 +25,7 @@ void CBC_UtilCodingConvert::LocaleToUtf8(const CFX_ByteString& src,
                                          std::vector<uint8_t>& dst) {
   CFX_WideString unicode = CFX_WideString::FromLocal(src.AsStringC());
   CFX_ByteString utf8 = unicode.UTF8Encode();
-  for (int32_t i = 0; i < utf8.GetLength(); i++) {
-    dst.push_back(utf8[i]);
-  }
+  dst = std::vector<uint8_t>(utf8.begin(), utf8.end());
 }
 
 void CBC_UtilCodingConvert::Utf8ToLocale(const std::vector<uint8_t>& src,
diff --git a/fxbarcode/datamatrix/BC_Base256Encoder.cpp b/fxbarcode/datamatrix/BC_Base256Encoder.cpp
index 1b8db85bdd..dd49c8e0f5 100644
--- a/fxbarcode/datamatrix/BC_Base256Encoder.cpp
+++ b/fxbarcode/datamatrix/BC_Base256Encoder.cpp
@@ -70,9 +70,8 @@ void CBC_Base256Encoder::Encode(CBC_EncoderContext& context, int32_t& e) {
       return;
     }
   }
-  for (int32_t i = 0, c = buffer.GetLength(); i < c; i++) {
-    context.writeCodeword(
-        randomize255State(buffer.GetAt(i), context.getCodewordCount() + 1));
+  for (const auto& c : buffer) {
+    context.writeCodeword(randomize255State(c, context.getCodewordCount() + 1));
   }
 }
 wchar_t CBC_Base256Encoder::randomize255State(wchar_t ch,
diff --git a/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp b/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp
index 041272ef8c..cce9749749 100644
--- a/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp
+++ b/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp
@@ -63,8 +63,7 @@ std::vector<uint8_t>& CBC_HighLevelEncoder::getBytesForMessage(
     CFX_WideString msg) {
   CFX_ByteString bytestr;
   CBC_UtilCodingConvert::UnicodeToUTF8(msg, bytestr);
-  for (int32_t i = 0; i < bytestr.GetLength(); i++)
-    m_bytearray.push_back(bytestr.GetAt(i));
+  m_bytearray.insert(m_bytearray.end(), bytestr.begin(), bytestr.end());
   return m_bytearray;
 }
 CFX_WideString CBC_HighLevelEncoder::encodeHighLevel(CFX_WideString msg,
diff --git a/fxbarcode/oned/BC_OnedCodaBarWriter.cpp b/fxbarcode/oned/BC_OnedCodaBarWriter.cpp
index 6c04cafe7b..d3706ab96d 100644
--- a/fxbarcode/oned/BC_OnedCodaBarWriter.cpp
+++ b/fxbarcode/oned/BC_OnedCodaBarWriter.cpp
@@ -108,18 +108,11 @@ bool CBC_OnedCodaBarWriter::FindChar(wchar_t ch, bool isContent) {
 }
 bool CBC_OnedCodaBarWriter::CheckContentValidity(
     const CFX_WideStringC& contents) {
-  wchar_t ch;
-  int32_t index = 0;
-  for (index = 0; index < contents.GetLength(); index++) {
-    ch = contents.GetAt(index);
-    if (FindChar(ch, false)) {
-      continue;
-    } else {
-      return false;
-    }
-  }
-  return true;
+  return std::all_of(
+      contents.begin(), contents.end(),
+      [this](const wchar_t& ch) { return this->FindChar(ch, false); });
 }
+
 CFX_WideString CBC_OnedCodaBarWriter::FilterContents(
     const CFX_WideStringC& contents) {
   CFX_WideString filtercontents;
diff --git a/fxbarcode/oned/BC_OnedCode128Writer.cpp b/fxbarcode/oned/BC_OnedCode128Writer.cpp
index 53f4d01449..e2b6823414 100644
--- a/fxbarcode/oned/BC_OnedCode128Writer.cpp
+++ b/fxbarcode/oned/BC_OnedCode128Writer.cpp
@@ -113,22 +113,14 @@ CFX_WideString CBC_OnedCode128Writer::FilterContents(
   }
   CFX_WideString filtercontents;
   if (m_codeFormat == BC_CODE128_B) {
-    for (int32_t i = 0; i < filterChineseChar.GetLength(); i++) {
-      ch = filterChineseChar.GetAt(i);
-      if (ch >= 32 && ch <= 126) {
+    for (const auto& ch : filterChineseChar) {
+      if (ch >= 32 && ch <= 126)
         filtercontents += ch;
-      } else {
-        continue;
-      }
     }
   } else if (m_codeFormat == BC_CODE128_C) {
-    for (int32_t i = 0; i < filterChineseChar.GetLength(); i++) {
-      ch = filterChineseChar.GetAt(i);
-      if (ch >= 32 && ch <= 106) {
+    for (const auto& ch : filterChineseChar) {
+      if (ch >= 32 && ch <= 106)
         filtercontents += ch;
-      } else {
-        continue;
-      }
     }
   } else {
     filtercontents = contents;
diff --git a/fxbarcode/oned/BC_OnedCode39Writer.cpp b/fxbarcode/oned/BC_OnedCode39Writer.cpp
index bcc64d83bd..b1a56cad40 100644
--- a/fxbarcode/oned/BC_OnedCode39Writer.cpp
+++ b/fxbarcode/oned/BC_OnedCode39Writer.cpp
@@ -163,11 +163,11 @@ char CBC_OnedCode39Writer::CalcCheckSum(const CFX_ByteString& contents,
   }
   int32_t checksum = 0;
   int32_t len = (int32_t)strlen(ALPHABET_STRING);
-  for (int32_t i = 0; i < contents.GetLength(); i++) {
+  for (const auto& c : contents) {
     int32_t j = 0;
     for (; j < len; j++) {
-      if (ALPHABET_STRING[j] == contents[i]) {
-        if (contents[i] != '*')
+      if (ALPHABET_STRING[j] == c) {
+        if (c != '*')
           checksum += j;
         break;
       }
diff --git a/fxbarcode/oned/BC_OnedEAN13Writer.cpp b/fxbarcode/oned/BC_OnedEAN13Writer.cpp
index a11938a4d9..96b51b0570 100644
--- a/fxbarcode/oned/BC_OnedEAN13Writer.cpp
+++ b/fxbarcode/oned/BC_OnedEAN13Writer.cpp
@@ -48,17 +48,13 @@ CBC_OnedEAN13Writer::CBC_OnedEAN13Writer() {
   m_codeWidth = 3 + (7 * 6) + 5 + (7 * 6) + 3;
 }
 CBC_OnedEAN13Writer::~CBC_OnedEAN13Writer() {}
+
 bool CBC_OnedEAN13Writer::CheckContentValidity(
     const CFX_WideStringC& contents) {
-  for (int32_t i = 0; i < contents.GetLength(); i++) {
-    if (contents.GetAt(i) >= '0' && contents.GetAt(i) <= '9') {
-      continue;
-    } else {
-      return false;
-    }
-  }
-  return true;
+  return std::all_of(contents.begin(), contents.end(),
+                     [](const wchar_t& w) { return w >= L'0' && w <= L'9'; });
 }
+
 CFX_WideString CBC_OnedEAN13Writer::FilterContents(
     const CFX_WideStringC& contents) {
   CFX_WideString filtercontents;
diff --git a/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp b/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp
index ac8b0186f6..f65cfe46ae 100644
--- a/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp
+++ b/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp
@@ -71,10 +71,7 @@ CFX_WideString CBC_PDF417HighLevelEncoder::encodeHighLevel(
     }
     msg += ch;
   }
-  std::vector<uint8_t> byteArr;
-  for (int32_t k = 0; k < bytes.GetLength(); k++) {
-    byteArr.push_back(bytes.GetAt(k));
-  }
+  std::vector<uint8_t> byteArr(bytes.begin(), bytes.end());
   CFX_WideString sb;
   len = msg.GetLength();
   int32_t p = 0;
diff --git a/xfa/fgas/layout/fgas_rtfbreak_unittest.cpp b/xfa/fgas/layout/fgas_rtfbreak_unittest.cpp
index d84621a595..cc3c86cadb 100644
--- a/xfa/fgas/layout/fgas_rtfbreak_unittest.cpp
+++ b/xfa/fgas/layout/fgas_rtfbreak_unittest.cpp
@@ -53,8 +53,8 @@ TEST_F(RTFBreakTest, AddChars) {
   auto b = CreateBreak(FX_LAYOUTSTYLE_ExpandTab);
 
   CFX_WideString str(L"Input String.");
-  for (int32_t i = 0; i < str.GetLength(); i++)
-    EXPECT_EQ(CFX_BreakType::None, b->AppendChar(str.GetAt(i)));
+  for (const auto& c : str)
+    EXPECT_EQ(CFX_BreakType::None, b->AppendChar(c));
 
   EXPECT_EQ(CFX_BreakType::Paragraph, b->AppendChar(L'\n'));
   ASSERT_EQ(1, b->CountBreakPieces());
@@ -65,8 +65,8 @@ TEST_F(RTFBreakTest, AddChars) {
   EXPECT_EQ(0, b->GetCurrentLineForTesting()->GetLineEnd());
 
   str = L"Second str.";
-  for (int32_t i = 0; i < str.GetLength(); i++)
-    EXPECT_EQ(CFX_BreakType::None, b->AppendChar(str.GetAt(i)));
+  for (const auto& c : str)
+    EXPECT_EQ(CFX_BreakType::None, b->AppendChar(c));
 
   // Force the end of the break at the end of the string.
   b->EndBreak(CFX_BreakType::Paragraph);
diff --git a/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp b/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp
index ead2a7dbe3..4621dfe134 100644
--- a/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp
+++ b/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp
@@ -3472,8 +3472,7 @@ void CXFA_FM2JSContext::EncodeURL(const CFX_ByteStringC& szURLString,
   wchar_t strReserved[] = {';', '/', '?', ':', '@', '=', '&'};
   wchar_t strSpecial[] = {'$', '-', '+', '!', '*', '\'', '(', ')', ','};
   const wchar_t* strCode = L"0123456789abcdef";
-  for (int32_t u = 0; u < wsURLString.GetLength(); ++u) {
-    wchar_t ch = wsURLString.GetAt(u);
+  for (auto ch : wsURLString) {
     int32_t i = 0;
     int32_t iCount = FX_ArraySize(strUnsafe);
     while (i < iCount) {
@@ -3624,9 +3623,7 @@ void CXFA_FM2JSContext::EncodeXML(const CFX_ByteStringC& szXMLString,
   strEncode[7] = ';';
   strEncode[8] = 0;
   const wchar_t* strCode = L"0123456789abcdef";
-  const wchar_t* pData = wsXMLString.c_str();
-  for (int32_t u = 0; u < wsXMLString.GetLength(); ++u) {
-    wchar_t ch = pData[u];
+  for (const auto& ch : wsXMLString) {
     switch (ch) {
       case '"':
         wsResultBuf.AppendChar('&');