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      1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef PPAPI_CPP_DIRECTORY_ENTRY_H_
      6 #define PPAPI_CPP_DIRECTORY_ENTRY_H_
      7 
      8 #include <vector>
      9 
     10 #include "ppapi/c/pp_array_output.h"
     11 #include "ppapi/c/pp_directory_entry.h"
     12 #include "ppapi/cpp/array_output.h"
     13 #include "ppapi/cpp/file_ref.h"
     14 #include "ppapi/cpp/output_traits.h"
     15 #include "ppapi/cpp/pass_ref.h"
     16 
     17 /// @file
     18 /// This file defines the API used to handle a directory entry.
     19 
     20 namespace pp {
     21 
     22 /// The <code>DirectoryEntry</code> class represents information about
     23 /// a directory entry.
     24 class DirectoryEntry {
     25  public:
     26   /// Default constructor for creating an is_null() <code>DirectoryEntry</code>
     27   /// object.
     28   DirectoryEntry();
     29 
     30   /// A constructor used when you have a <code>PP_DirectoryEntry</code> which
     31   /// contains a <code>FileRef</code> that has already been reference counted
     32   /// as a return value.
     33   ///
     34   /// @param[in] data A <code>PP_DirectoryEntry</code> to be copied.
     35   DirectoryEntry(PassRef, const PP_DirectoryEntry& data);
     36 
     37   /// A copy constructor for <code>DirectoryEntry</code>. This constructor
     38   /// increments a reference count of the <code>FileRef</code> held by this
     39   /// DirectoryEntry.
     40   ///
     41   /// @param[in] other A pointer to a <code>DirectoryEntry</code>.
     42   DirectoryEntry(const DirectoryEntry& other);
     43 
     44   /// A destructor that decrements a reference count of the <code>FileRef</code>
     45   /// held by this <code>DirectoryEntry</code>.
     46   ~DirectoryEntry();
     47 
     48   /// This function assigns one <code>DirectoryEntry</code> object to this
     49   /// <code>DirectoryEntry</code> object. This function increases the reference
     50   /// count of the <code>FileRef</code> of the other DirectoryEntry while
     51   /// decrementing the reference count of the FileRef of this DirectoryEntry.
     52   ///
     53   /// @param[in] other A pointer to a <code>DirectoryEntry</code>.
     54   ///
     55   /// @return A new <code>DirectoryEntry</code> object.
     56   DirectoryEntry& operator=(const DirectoryEntry& other);
     57 
     58   /// This function determines if this <code>DirectoryEntry</code> is a null
     59   /// value.
     60   ///
     61   /// @return true if this <code>DirectoryEntry</code> is null, otherwise false.
     62   bool is_null() const { return !data_.file_ref; }
     63 
     64   /// This function returns the <code>FileRef</code> held by this
     65   /// <code>DirectoryEntry</code>.
     66   ///
     67   /// @return A <code>FileRef</code> of the file.
     68   FileRef file_ref() const { return FileRef(data_.file_ref); }
     69 
     70   /// This function returns the <code>PP_FileType</code> of the file referenced
     71   /// by this <code>DirectoryEntry</code>.
     72   ///
     73   /// @return A <code>PP_FileType</code> of the file.
     74   PP_FileType file_type() const { return data_.file_type; }
     75 
     76  private:
     77   PP_DirectoryEntry data_;
     78 };
     79 
     80 namespace internal {
     81 
     82 class DirectoryEntryArrayOutputAdapterWithStorage
     83     : public ArrayOutputAdapter<PP_DirectoryEntry> {
     84  public:
     85   DirectoryEntryArrayOutputAdapterWithStorage();
     86   virtual ~DirectoryEntryArrayOutputAdapterWithStorage();
     87 
     88   // Returns the final array of resource objects, converting the
     89   // PP_DirectoryEntry written by the browser to pp::DirectoryEntry
     90   // objects.
     91   //
     92   // This function should only be called once or we would end up converting
     93   // the array more than once, which would mess up the refcounting.
     94   std::vector<DirectoryEntry>& output();
     95 
     96  private:
     97   // The browser will write the PP_DirectoryEntrys into this array.
     98   std::vector<PP_DirectoryEntry> temp_storage_;
     99 
    100   // When asked for the output, the PP_DirectoryEntrys above will be
    101   // converted to the pp::DirectoryEntrys in this array for passing to the
    102   // calling code.
    103   std::vector<DirectoryEntry> output_storage_;
    104 };
    105 
    106 // A specialization of CallbackOutputTraits to provide the callback system the
    107 // information on how to handle vectors of pp::DirectoryEntry. This converts
    108 // PP_DirectoryEntry to pp::DirectoryEntry when passing to the plugin.
    109 template <>
    110 struct CallbackOutputTraits< std::vector<DirectoryEntry> > {
    111   typedef PP_ArrayOutput APIArgType;
    112   typedef DirectoryEntryArrayOutputAdapterWithStorage StorageType;
    113 
    114   static inline APIArgType StorageToAPIArg(StorageType& t) {
    115     return t.pp_array_output();
    116   }
    117 
    118   static inline std::vector<DirectoryEntry>& StorageToPluginArg(
    119       StorageType& t) {
    120     return t.output();
    121   }
    122 
    123   static inline void Initialize(StorageType* /* t */) {}
    124 };
    125 
    126 }  // namespace internal
    127 }  // namespace pp
    128 
    129 #endif  // PPAPI_CPP_DIRECTORY_ENTRY_H_
    130