text: // Copyright (c) 2010 Marshall A. Greenblatt. All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //    * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //    * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //    * Neither the name of Google Inc. nor the name Chromium Embedded
  // Framework nor the names of its contributors may be used to endorse
  // or promote products derived from this software without specific prior
  // written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #ifndef CEF_INCLUDE_INTERNAL_CEF_STRING_WRAPPERS_H_
  #define CEF_INCLUDE_INTERNAL_CEF_STRING_WRAPPERS_H_
  #pragma once
  
  #include <memory.h>
  #include <string>
  
  #include "include/base/cef_string16.h"
  #include "include/internal/cef_string_types.h"
  
  ///
  // Traits implementation for wide character strings.
  ///
  struct CefStringTraitsWide {
    typedef wchar_t char_type;
    typedef cef_string_wide_t struct_type;
    typedef cef_string_userfree_wide_t userfree_struct_type;
  
    static inline void clear(struct_type *s) { cef_string_wide_clear(s); }
    static inline int set(const char_type* src, size_t src_size,
                          struct_type* output, int copy) {
      return cef_string_wide_set(src, src_size, output, copy);
    }
    static inline int compare(const struct_type* s1, const struct_type* s2) {
      return cef_string_wide_cmp(s1, s2);
    }
    static inline userfree_struct_type userfree_alloc() {
      return cef_string_userfree_wide_alloc();
    }
    static inline void userfree_free(userfree_struct_type ufs) {
      return cef_string_userfree_wide_free(ufs);
    }
  
    // Conversion methods.
    static inline bool from_ascii(const char* str, size_t len, struct_type *s) {
      return cef_string_ascii_to_wide(str, len, s) ? true : false;
    }
    static inline std::string to_string(const struct_type *s) {
      cef_string_utf8_t cstr;
      memset(&cstr, 0, sizeof(cstr));
      cef_string_wide_to_utf8(s->str, s->length, &cstr);
      std::string str;
      if (cstr.length > 0)
        str = std::string(cstr.str, cstr.length);
      cef_string_utf8_clear(&cstr);
      return str;
    }
    static inline bool from_string(const std::string& str, struct_type *s) {
      return cef_string_utf8_to_wide(str.c_str(), str.length(), s) ? true : false;
    }
    static inline std::wstring to_wstring(const struct_type *s) {
      return std::wstring(s->str, s->length);
    }
    static inline bool from_wstring(const std::wstring& str, struct_type *s) {
      return cef_string_wide_set(str.c_str(), str.length(), s, true) ?
          true : false;
    }
  #if defined(WCHAR_T_IS_UTF32)
    static inline base::string16 to_string16(const struct_type *s) {
      cef_string_utf16_t cstr;
      memset(&cstr, 0, sizeof(cstr));
      cef_string_wide_to_utf16(s->str, s->length, &cstr);
      base::string16 str;
      if (cstr.length > 0)
        str = base::string16(cstr.str, cstr.length);
      cef_string_utf16_clear(&cstr);
      return str;
    }
    static inline bool from_string16(const base::string16& str,
                                           struct_type *s) {
      return cef_string_utf16_to_wide(str.c_str(), str.length(), s) ?
          true : false;
    }
  #else  // WCHAR_T_IS_UTF32
    static inline base::string16 to_string16(const struct_type *s) {
      return base::string16(s->str, s->length);
    }
    static inline bool from_string16(const base::string16& str, struct_type *s) {
      return cef_string_wide_set(str.c_str(), str.length(), s, true) ?
          true : false;
    }
  #endif  // WCHAR_T_IS_UTF32
  };
  
  ///
  // Traits implementation for utf8 character strings.
  ///
  struct CefStringTraitsUTF8 {
    typedef char char_type;
    typedef cef_string_utf8_t struct_type;
    typedef cef_string_userfree_utf8_t userfree_struct_type;
  
    static inline void clear(struct_type *s) { cef_string_utf8_clear(s); }
    static inline int set(const char_type* src, size_t src_size,
                          struct_type* output, int copy) {
      return cef_string_utf8_set(src, src_size, output, copy);
    }
    static inline int compare(const struct_type* s1, const struct_type* s2) {
      return cef_string_utf8_cmp(s1, s2);
    }
    static inline userfree_struct_type userfree_alloc() {
      return cef_string_userfree_utf8_alloc();
    }
    static inline void userfree_free(userfree_struct_type ufs) {
      return cef_string_userfree_utf8_free(ufs);
    }
  
    // Conversion methods.
    static inline bool from_ascii(const char* str, size_t len, struct_type* s) {
      return cef_string_utf8_copy(str, len, s) ? true : false;
    }
    static inline std::string to_string(const struct_type* s) {
      return std::string(s->str, s->length);
    }
    static inline bool from_string(const std::string& str, struct_type* s) {
      return cef_string_utf8_copy(str.c_str(), str.length(), s) ? true : false;
    }
    static inline std::wstring to_wstring(const struct_type* s) {
      cef_string_wide_t cstr;
      memset(&cstr, 0, sizeof(cstr));
      cef_string_utf8_to_wide(s->str, s->length, &cstr);
      std::wstring str;
      if (cstr.length > 0)
        str = std::wstring(cstr.str, cstr.length);
      cef_string_wide_clear(&cstr);
      return str;
    }
    static inline bool from_wstring(const std::wstring& str, struct_type* s) {
      return cef_string_wide_to_utf8(str.c_str(), str.length(), s) ? true : false;
    }
    static inline base::string16 to_string16(const struct_type* s) {
      cef_string_utf16_t cstr;
      memset(&cstr, 0, sizeof(cstr));
      cef_string_utf8_to_utf16(s->str, s->length, &cstr);
      base::string16 str;
      if (cstr.length > 0)
        str = base::string16(cstr.str, cstr.length);
      cef_string_utf16_clear(&cstr);
      return str;
    }
    static inline bool from_string16(const base::string16& str, struct_type* s) {
      return cef_string_utf16_to_utf8(str.c_str(), str.length(), s) ?
          true : false;
    }
  };
  
  ///
  // Traits implementation for utf16 character strings.
  ///
  struct CefStringTraitsUTF16 {
    typedef char16 char_type;
    typedef cef_string_utf16_t struct_type;
    typedef cef_string_userfree_utf16_t userfree_struct_type;
  
    static inline void clear(struct_type *s) { cef_string_utf16_clear(s); }
    static inline int set(const char_type* src, size_t src_size,
                          struct_type* output, int copy) {
      return cef_string_utf16_set(src, src_size, output, copy);
    }
    static inline int compare(const struct_type* s1, const struct_type* s2) {
      return cef_string_utf16_cmp(s1, s2);
    }
    static inline userfree_struct_type userfree_alloc() {
      return cef_string_userfree_utf16_alloc();
    }
    static inline void userfree_free(userfree_struct_type ufs) {
      return cef_string_userfree_utf16_free(ufs);
    }
  
    // Conversion methods.
    static inline bool from_ascii(const char* str, size_t len, struct_type* s) {
      return cef_string_ascii_to_utf16(str, len, s) ? true : false;
    }
    static inline std::string to_string(const struct_type* s) {
      cef_string_utf8_t cstr;
      memset(&cstr, 0, sizeof(cstr));
      cef_string_utf16_to_utf8(s->str, s->length, &cstr);
      std::string str;
      if (cstr.length > 0)
        str = std::string(cstr.str, cstr.length);
      cef_string_utf8_clear(&cstr);
      return str;
    }
    static inline bool from_string(const std::string& str, struct_type* s) {
      return cef_string_utf8_to_utf16(str.c_str(), str.length(), s) ?
          true : false;
    }
  #if defined(WCHAR_T_IS_UTF32)
    static inline std::wstring to_wstring(const struct_type* s) {
      cef_string_wide_t cstr;
      memset(&cstr, 0, sizeof(cstr));
      cef_string_utf16_to_wide(s->str, s->length, &cstr);
      std::wstring str;
      if (cstr.length > 0)
        str = std::wstring(cstr.str, cstr.length);
      cef_string_wide_clear(&cstr);
      return str;
    }
    static inline bool from_wstring(const std::wstring& str, struct_type* s) {
      return cef_string_wide_to_utf16(str.c_str(), str.length(), s) ?
          true : false;
    }
  #else  // WCHAR_T_IS_UTF32
    static inline std::wstring to_wstring(const struct_type* s) {
      return std::wstring(s->str, s->length);
    }
    static inline bool from_wstring(const std::wstring& str, struct_type* s) {
      return cef_string_utf16_set(str.c_str(), str.length(), s, true) ?
          true : false;
    }
  #endif  // WCHAR_T_IS_UTF32
    static inline base::string16 to_string16(const struct_type* s) {
      return base::string16(s->str, s->length);
    }
    static inline bool from_string16(const base::string16& str, struct_type* s) {
      return cef_string_utf16_set(str.c_str(), str.length(), s, true) ?
          true : false;
    }
  };
  
  ///
  // CEF string classes can convert between all supported string types. For
  // example, the CefStringWide class uses wchar_t as the underlying character
  // type and provides two approaches for converting data to/from a UTF8 string
  // (std::string).
  // <p>
  // 1. Implicit conversion using the assignment operator overload.
  // <pre>
  //   CefStringWide aCefString;
  //   std::string aUTF8String;
  //   aCefString = aUTF8String; // Assign std::string to CefStringWide
  //   aUTF8String = aCefString; // Assign CefStringWide to std::string
  // </pre>
  // 2. Explicit conversion using the FromString/ToString methods.
  // <pre>
  //   CefStringWide aCefString;
  //   std::string aUTF8String;
  //   aCefString.FromString(aUTF8String); // Assign std::string to CefStringWide
  //   aUTF8String = aCefString.ToString(); // Assign CefStringWide to std::string
  // </pre>
  // Conversion will only occur if the assigned value is a different string type.
  // Assigning a std::string to a CefStringUTF8, for example, will copy the data
  // without performing a conversion.
  // </p>
  // CEF string classes are safe for reading from multiple threads but not for
  // modification. It is the user's responsibility to provide synchronization if
  // modifying CEF strings from multiple threads.
  ///
  template <class traits>
  class CefStringBase {
   public:
    typedef typename traits::char_type char_type;
    typedef typename traits::struct_type struct_type;
    typedef typename traits::userfree_struct_type userfree_struct_type;
  
    ///
    // Default constructor.
    ///
    CefStringBase() : string_(NULL), owner_(false) {}
  
    ///
    // Create a new string from an existing string. Data will always be copied.
    ///
    CefStringBase(const CefStringBase& str)
      : string_(NULL), owner_(false) {
      FromString(str.c_str(), str.length(), true);
    }
  
    ///
    // Create a new string from an existing std::string. Data will be always
    // copied. Translation will occur if necessary based on the underlying string
    // type.
    ///
    CefStringBase(const std::string& src)  // NOLINT(runtime/explicit)
      : string_(NULL), owner_(false) {
      FromString(src);
    }
    CefStringBase(const char* src)  // NOLINT(runtime/explicit)
      : string_(NULL), owner_(false) {
      if (src)
        FromString(std::string(src));
    }
  
    ///
    // Create a new string from an existing std::wstring. Data will be always
    // copied. Translation will occur if necessary based on the underlying string
    // type.
    ///
    CefStringBase(const std::wstring& src)  // NOLINT(runtime/explicit)
      : string_(NULL), owner_(false) {
      FromWString(src);
    }
    CefStringBase(const wchar_t* src)  // NOLINT(runtime/explicit)
      : string_(NULL), owner_(false) {
      if (src)
        FromWString(std::wstring(src));
    }
  
  #if defined(WCHAR_T_IS_UTF32)
    ///
    // Create a new string from an existing string16. Data will be always
    // copied. Translation will occur if necessary based on the underlying string
    // type.
    ///
    CefStringBase(const base::string16& src)  // NOLINT(runtime/explicit)
      : string_(NULL), owner_(false) {
      FromString16(src);
    }
    CefStringBase(const char16* src)  // NOLINT(runtime/explicit)
      : string_(NULL), owner_(false) {
      if (src)
        FromString16(base::string16(src));
    }
  #endif  // WCHAR_T_IS_UTF32
  
    ///
    // Create a new string from an existing character array. If |copy| is true
    // this class will copy the data. Otherwise, this class will reference the
    // existing data. Referenced data must exist for the lifetime of this class
    // and will not be freed by this class.
    ///
    CefStringBase(const char_type* src, size_t src_len, bool copy)
      : string_(NULL), owner_(false) {
      if (src && src_len > 0)
        FromString(src, src_len, copy);
    }
  
    ///
    // Create a new string referencing an existing string structure without taking
    // ownership. Referenced structures must exist for the lifetime of this class
    // and will not be freed by this class.
    ///
    CefStringBase(const struct_type* src)  // NOLINT(runtime/explicit)
      : string_(NULL), owner_(false) {
      if (!src)
        return;
      // Reference the existing structure without taking ownership.
      Attach(const_cast<struct_type*>(src), false);
    }
  
    virtual ~CefStringBase() { ClearAndFree(); }
  
  
    // The following methods are named for compatibility with the standard library
    // string template types.
  
    ///
    // Return a read-only pointer to the string data.
    ///
    const char_type* c_str() const { return (string_ ? string_->str : NULL); }
  
    ///
    // Return the length of the string data.
    ///
    size_t length() const { return (string_ ? string_->length : 0); }
  
    ///
    // Return the length of the string data.
    ///
    inline size_t size() const { return length(); }
  
    ///
    // Returns true if the string is empty.
    ///
    bool empty() const { return (string_ == NULL || string_->length == 0); }
  
    ///
    // Compare this string to the specified string.
    ///
    int compare(const CefStringBase& str) const {
      if (empty() && str.empty())
        return 0;
      if (empty())
        return -1;
      if (str.empty())
        return 1;
      return traits::compare(string_, str.GetStruct());
    }
  
    ///
    // Clear the string data.
    ///
    void clear() {
      if (string_)
        traits::clear(string_);
    }
  
    ///
    // Swap this string's contents with the specified string.
    ///
    void swap(CefStringBase& str) {
      struct_type* tmp_string = string_;
      bool tmp_owner = owner_;
      string_ = str.string_;
      owner_ = str.owner_;
      str.string_ = tmp_string;
      str.owner_ = tmp_owner;
    }
  
  
    // The following methods are unique to CEF string template types.
  
    ///
    // Returns true if this class owns the underlying string structure.
    ///
    bool IsOwner() const { return owner_; }
  
    ///
    // Returns a read-only pointer to the underlying string structure. May return
    // NULL if no structure is currently allocated.
    ///
    const struct_type* GetStruct() const { return string_; }
  
    ///
    // Returns a writable pointer to the underlying string structure. Will never
    // return NULL.
    ///
    struct_type* GetWritableStruct() {
      AllocIfNeeded();
      return string_;
    }
  
    ///
    // Clear the state of this class. The underlying string structure and data
    // will be freed if this class owns the structure.
    ///
    void ClearAndFree() {
      if (!string_)
        return;
      if (owner_) {
        clear();
        delete string_;
      }
      string_ = NULL;
      owner_ = false;
    }
  
    ///
    // Attach to the specified string structure. If |owner| is true this class
    // will take ownership of the structure.
    ///
    void Attach(struct_type* str, bool owner) {
      // Free the previous structure and data, if any.
      ClearAndFree();
  
      string_ = str;
      owner_ = owner;
    }
  
    ///
    // Take ownership of the specified userfree structure's string data. The
    // userfree structure itself will be freed. Only use this method with userfree
    // structures.
    ///
    void AttachToUserFree(userfree_struct_type str) {
      // Free the previous structure and data, if any.
      ClearAndFree();
  
      if (!str)
        return;
  
      AllocIfNeeded();
      owner_ = true;
      memcpy(string_, str, sizeof(struct_type));
  
      // Free the |str| structure but not the data.
      memset(str, 0, sizeof(struct_type));
      traits::userfree_free(str);
    }
  
    ///
    // Detach from the underlying string structure. To avoid memory leaks only use
    // this method if you already hold a pointer to the underlying string
    // structure.
    ///
    void Detach() {
      string_ = NULL;
      owner_ = false;
    }
  
    ///
    // Create a userfree structure and give it ownership of this class' string
    // data. This class will be disassociated from the data. May return NULL if
    // this string class currently contains no data.
    ///
    userfree_struct_type DetachToUserFree() {
      if (empty())
        return NULL;
  
      userfree_struct_type str = traits::userfree_alloc();
      memcpy(str, string_, sizeof(struct_type));
  
      // Free this class' structure but not the data.
      memset(string_, 0, sizeof(struct_type));
      ClearAndFree();
  
      return str;
    }
  
    ///
    // Set this string's data to the specified character array. If |copy| is true
    // this class will copy the data. Otherwise, this class will reference the
    // existing data. Referenced data must exist for the lifetime of this class
    // and will not be freed by this class.
    ///
    bool FromString(const char_type* src, size_t src_len, bool copy) {
      if (src == NULL || src_len == 0) {
        clear();
        return true;
      }
      AllocIfNeeded();
      return traits::set(src, src_len, string_, copy) ? true : false;
    }
  
    ///
    // Set this string's data from an existing ASCII string. Data will be always
    // copied. Translation will occur if necessary based on the underlying string
    // type.
    ///
    bool FromASCII(const char* str) {
      size_t len = str ? strlen(str) : 0;
      if (len == 0) {
        clear();
        return true;
      }
      AllocIfNeeded();
      return traits::from_ascii(str, len, string_);
    }
  
    ///
    // Return this string's data as a std::string. Translation will occur if
    // necessary based on the underlying string type.
    ///
    std::string ToString() const {
      if (empty())
        return std::string();
      return traits::to_string(string_);
    }
  
    ///
    // Set this string's data from an existing std::string. Data will be always
    // copied. Translation will occur if necessary based on the underlying string
    // type.
    ///
    bool FromString(const std::string& str) {
      if (str.empty()) {
        clear();
        return true;
      }
      AllocIfNeeded();
      return traits::from_string(str, string_);
    }
  
    ///
    // Return this string's data as a std::wstring. Translation will occur if
    // necessary based on the underlying string type.
    ///
    std::wstring ToWString() const {
      if (empty())
        return std::wstring();
      return traits::to_wstring(string_);
    }
  
    ///
    // Set this string's data from an existing std::wstring. Data will be always
    // copied. Translation will occur if necessary based on the underlying string
    // type.
    ///
    bool FromWString(const std::wstring& str) {
      if (str.empty()) {
        clear();
        return true;
      }
      AllocIfNeeded();
      return traits::from_wstring(str, string_);
    }
  
    ///
    // Return this string's data as a string16. Translation will occur if
    // necessary based on the underlying string type.
    ///
    base::string16 ToString16() const {
      if (empty())
        return base::string16();
      return traits::to_string16(string_);
    }
  
    ///
    // Set this string's data from an existing string16. Data will be always
    // copied. Translation will occur if necessary based on the underlying string
    // type.
    ///
    bool FromString16(const base::string16& str) {
      if (str.empty()) {
        clear();
        return true;
      }
      AllocIfNeeded();
      return traits::from_string16(str, string_);
    }
  
    ///
    // Comparison operator overloads.
    ///
    bool operator<(const CefStringBase& str) const {
      return (compare(str) < 0);
    }
    bool operator<=(const CefStringBase& str) const {
      return (compare(str) <= 0);
    }
    bool operator>(const CefStringBase& str) const {
      return (compare(str) > 0);
    }
    bool operator>=(const CefStringBase& str) const {
      return (compare(str) >= 0);
    }
    bool operator==(const CefStringBase& str) const {
      return (compare(str) == 0);
    }
    bool operator!=(const CefStringBase& str) const {
      return (compare(str) != 0);
    }
  
    ///
    // Assignment operator overloads.
    ///
    CefStringBase& operator=(const CefStringBase& str) {
      FromString(str.c_str(), str.length(), true);
      return *this;
    }
    operator std::string() const {
      return ToString();
    }
    CefStringBase& operator=(const std::string& str) {
      FromString(str);
      return *this;
    }
    CefStringBase& operator=(const char* str) {
      FromString(std::string(str));
      return *this;
    }
    operator std::wstring() const {
      return ToWString();
    }
    CefStringBase& operator=(const std::wstring& str) {
      FromWString(str);
      return *this;
    }
    CefStringBase& operator=(const wchar_t* str) {
      FromWString(std::wstring(str));
      return *this;
    }
  #if defined(WCHAR_T_IS_UTF32)
    operator base::string16() const {
      return ToString16();
    }
    CefStringBase& operator=(const base::string16& str) {
      FromString16(str);
      return *this;
    }
    CefStringBase& operator=(const char16* str) {
      FromString16(base::string16(str));
      return *this;
    }
  #endif  // WCHAR_T_IS_UTF32
  
   private:
    // Allocate the string structure if it doesn't already exist.
    void AllocIfNeeded() {
      if (string_ == NULL) {
        string_ = new struct_type;
        memset(string_, 0, sizeof(struct_type));
        owner_ = true;
      }
    }
  
    struct_type* string_;
    bool owner_;
  };
  
  
  typedef CefStringBase<CefStringTraitsWide> CefStringWide;
  typedef CefStringBase<CefStringTraitsUTF8> CefStringUTF8;
  typedef CefStringBase<CefStringTraitsUTF16> CefStringUTF16;
  
  #endif  // CEF_INCLUDE_INTERNAL_CEF_STRING_WRAPPERS_H_
  