| 1 | ///////////////////////////////////////////////////////////////////////////// |
| 2 | // Name: mstream.h |
| 3 | // Purpose: interface of wxMemoryOutputStream, wxMemoryInputStream |
| 4 | // Author: wxWidgets team |
| 5 | // Licence: wxWindows licence |
| 6 | ///////////////////////////////////////////////////////////////////////////// |
| 7 | |
| 8 | /** |
| 9 | @class wxMemoryOutputStream |
| 10 | |
| 11 | This class allows to use all methods taking a wxOutputStream reference to write |
| 12 | to in-memory data. |
| 13 | |
| 14 | Example: |
| 15 | @code |
| 16 | wxMemoryOutputStream stream; |
| 17 | if (!my_wxImage.SaveFile(stream)) |
| 18 | return; |
| 19 | |
| 20 | // now we can access the saved image bytes: |
| 21 | wxStreamBuffer* theBuffer = stream.GetOutputStreamBuffer(); |
| 22 | unsigned char byte; |
| 23 | if (theBuffer->Read(byte, 1) != 1) |
| 24 | return; |
| 25 | |
| 26 | // ... do something with 'byte'... |
| 27 | |
| 28 | // remember that ~wxMemoryOutputStream will destroy the internal |
| 29 | // buffer since we didn't provide our own when constructing it |
| 30 | @endcode |
| 31 | |
| 32 | @library{wxbase} |
| 33 | @category{streams} |
| 34 | |
| 35 | @see wxStreamBuffer |
| 36 | */ |
| 37 | class wxMemoryOutputStream : public wxOutputStream |
| 38 | { |
| 39 | public: |
| 40 | /** |
| 41 | If @a data is @NULL, then it will initialize a new empty buffer which will |
| 42 | grow if required. |
| 43 | |
| 44 | @warning |
| 45 | If the buffer is created by wxMemoryOutputStream, it will be destroyed |
| 46 | at the destruction of the stream. |
| 47 | */ |
| 48 | wxMemoryOutputStream(void* data = NULL, size_t length = 0); |
| 49 | |
| 50 | /** |
| 51 | Destructor. |
| 52 | |
| 53 | If the buffer wasn't provided by the user, it will be deleted here. |
| 54 | */ |
| 55 | virtual ~wxMemoryOutputStream(); |
| 56 | |
| 57 | /** |
| 58 | Allows you to transfer data from the internal buffer of wxMemoryOutputStream |
| 59 | to an external buffer. @a len specifies the size of the buffer. |
| 60 | */ |
| 61 | size_t CopyTo(void* buffer, size_t len) const; |
| 62 | |
| 63 | /** |
| 64 | Returns the pointer to the stream object used as an internal buffer |
| 65 | for this stream. |
| 66 | */ |
| 67 | wxStreamBuffer* GetOutputStreamBuffer() const; |
| 68 | }; |
| 69 | |
| 70 | |
| 71 | |
| 72 | /** |
| 73 | @class wxMemoryInputStream |
| 74 | |
| 75 | This class allows to use all methods taking a wxInputStream reference to read |
| 76 | in-memory data. |
| 77 | |
| 78 | Example: |
| 79 | @code |
| 80 | // we've got a block of memory containing a BMP image and we want |
| 81 | // to use wxImage to load it: |
| 82 | wxMemoryInputStream stream(my_memory_block, size); |
| 83 | |
| 84 | wxImage theBitmap; |
| 85 | if (!theBitmap.LoadFile(stream, wxBITMAP_TYPE_BMP)) |
| 86 | return; |
| 87 | |
| 88 | // we can now safely delete the original memory buffer as the data |
| 89 | // has been decoded by wxImage: |
| 90 | delete [] my_memory_block; |
| 91 | @endcode |
| 92 | |
| 93 | @library{wxbase} |
| 94 | @category{streams} |
| 95 | |
| 96 | @see wxStreamBuffer, wxMemoryOutputStream |
| 97 | */ |
| 98 | class wxMemoryInputStream : public wxInputStream |
| 99 | { |
| 100 | public: |
| 101 | /** |
| 102 | Initializes a new read-only memory stream which will use the specified |
| 103 | buffer data of length len. The stream does not take ownership of the buffer, |
| 104 | i.e. the buffer will not be deleted in its destructor. |
| 105 | */ |
| 106 | wxMemoryInputStream(const void* data, size_t len); |
| 107 | |
| 108 | /** |
| 109 | Creates a new read-only memory stream, initializing it with the data from |
| 110 | the given output stream @a stream. |
| 111 | */ |
| 112 | wxMemoryInputStream(const wxMemoryOutputStream& stream); |
| 113 | |
| 114 | /** |
| 115 | Creates a new read-only memory stream, initializing it with the |
| 116 | data from the given input stream @a stream. |
| 117 | |
| 118 | The @a len argument specifies the amount of data to read from the |
| 119 | @a stream. Setting it to ::wxInvalidOffset means that the @a stream |
| 120 | is to be read entirely (i.e. till the EOF is reached). |
| 121 | */ |
| 122 | wxMemoryInputStream(wxInputStream& stream, |
| 123 | wxFileOffset len = wxInvalidOffset); |
| 124 | |
| 125 | /** |
| 126 | Destructor. Does NOT free the buffer provided in the ctor. |
| 127 | */ |
| 128 | virtual ~wxMemoryInputStream(); |
| 129 | |
| 130 | /** |
| 131 | Returns the pointer to the stream object used as an internal buffer |
| 132 | for that stream. |
| 133 | */ |
| 134 | wxStreamBuffer* GetInputStreamBuffer() const; |
| 135 | }; |
| 136 | |