fixed maximization handling
[wxWidgets.git] / include / wx / file.h
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: file.h
3 // Purpose: wxFile - encapsulates low-level "file descriptor"
4 // wxTempFile - safely replace the old file
5 // Author: Vadim Zeitlin
6 // Modified by:
7 // Created: 29/01/98
8 // RCS-ID: $Id$
9 // Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
10 // Licence: wxWindows license
11 /////////////////////////////////////////////////////////////////////////////
12
13 #ifndef _WX_FILEH__
14 #define _WX_FILEH__
15
16 #ifdef __GNUG__
17 #pragma interface "file.h"
18 #endif
19
20 #ifndef WX_PRECOMP
21 #include "wx/string.h"
22 #include "wx/filefn.h"
23 #endif
24
25 #if wxUSE_FILE
26
27 // ----------------------------------------------------------------------------
28 // constants
29 // ----------------------------------------------------------------------------
30
31 // we redefine these constants here because S_IREAD &c are _not_ standard
32 // however, we do assume that the values correspond to the Unix umask bits
33 #define wxS_IRUSR 00400
34 #define wxS_IWUSR 00200
35 #define wxS_IXUSR 00100
36
37 #define wxS_IRGRP 00040
38 #define wxS_IWGRP 00020
39 #define wxS_IXGRP 00010
40
41 #define wxS_IROTH 00004
42 #define wxS_IWOTH 00002
43 #define wxS_IXOTH 00001
44
45 // default mode for the new files: corresponds to umask 022
46 #define wxS_DEFAULT (wxS_IRUSR | wxS_IWUSR | wxS_IRGRP | wxS_IWGRP |\
47 wxS_IROTH | wxS_IWOTH)
48
49 // ----------------------------------------------------------------------------
50 // class wxFile: raw file IO
51 //
52 // NB: for space efficiency this class has no virtual functions, including
53 // dtor which is _not_ virtual, so it shouldn't be used as a base class.
54 // ----------------------------------------------------------------------------
55 class WXDLLEXPORT wxFile
56 {
57 public:
58 // more file constants
59 // -------------------
60 // opening mode
61 enum OpenMode { read, write, read_write, write_append };
62 // standard values for file descriptor
63 enum { fd_invalid = -1, fd_stdin, fd_stdout, fd_stderr };
64
65 // static functions
66 // ----------------
67 // check whether a regular file by this name exists
68 static bool Exists(const wxChar *name);
69 // check whetther we can access the given file in given mode
70 // (only read and write make sense here)
71 static bool Access(const wxChar *name, OpenMode mode);
72
73 // ctors
74 // -----
75 // def ctor
76 wxFile() { m_fd = fd_invalid; }
77 // open specified file (may fail, use IsOpened())
78 wxFile(const wxChar *szFileName, OpenMode mode = read);
79 // attach to (already opened) file
80 wxFile(int fd) { m_fd = fd; }
81
82 // open/close
83 // create a new file (with the default value of bOverwrite, it will fail if
84 // the file already exists, otherwise it will overwrite it and succeed)
85 bool Create(const wxChar *szFileName, bool bOverwrite = FALSE,
86 int access = wxS_DEFAULT);
87 bool Open(const wxChar *szFileName, OpenMode mode = read,
88 int access = wxS_DEFAULT);
89 bool Close(); // Close is a NOP if not opened
90
91 // assign an existing file descriptor and get it back from wxFile object
92 void Attach(int fd) { Close(); m_fd = fd; }
93 void Detach() { m_fd = fd_invalid; }
94 int fd() const { return m_fd; }
95
96 // read/write (unbuffered)
97 // returns number of bytes read or ofsInvalid on error
98 off_t Read(void *pBuf, off_t nCount);
99 // returns the number of bytes written
100 size_t Write(const void *pBuf, size_t nCount);
101 // returns true on success
102 bool Write(const wxString& s, wxMBConv& conv = wxConvLibc)
103 {
104 const wxWX2MBbuf buf = s.mb_str(conv);
105 size_t size = strlen(buf);
106 return Write((const char *) buf, size) == size;
107 }
108 // flush data not yet written
109 bool Flush();
110
111 // file pointer operations (return ofsInvalid on failure)
112 // move ptr ofs bytes related to start/current off_t/end of file
113 off_t Seek(off_t ofs, wxSeekMode mode = wxFromStart);
114 // move ptr to ofs bytes before the end
115 off_t SeekEnd(off_t ofs = 0) { return Seek(ofs, wxFromEnd); }
116 // get current off_t
117 off_t Tell() const;
118 // get current file length
119 off_t Length() const;
120
121 // simple accessors
122 // is file opened?
123 bool IsOpened() const { return m_fd != fd_invalid; }
124 // is end of file reached?
125 bool Eof() const;
126 // has an error occured?
127 bool Error() const { return m_error; }
128
129 // dtor closes the file if opened
130 ~wxFile() { Close(); }
131
132 private:
133 // copy ctor and assignment operator are private because
134 // it doesn't make sense to copy files this way:
135 // attempt to do it will provoke a compile-time error.
136 wxFile(const wxFile&);
137 wxFile& operator=(const wxFile&);
138
139 int m_fd; // file descriptor or INVALID_FD if not opened
140 bool m_error; // error memory
141 };
142
143 // ----------------------------------------------------------------------------
144 // class wxTempFile: if you want to replace another file, create an instance
145 // of wxTempFile passing the name of the file to be replaced to the ctor. Then
146 // you can write to wxTempFile and call Commit() function to replace the old
147 // file (and close this one) or call Discard() to cancel the modification. If
148 // you call neither of them, dtor will call Discard().
149 // ----------------------------------------------------------------------------
150 class WXDLLEXPORT wxTempFile
151 {
152 public:
153 // ctors
154 // default
155 wxTempFile() { }
156 // associates the temp file with the file to be replaced and opens it
157 wxTempFile(const wxString& strName);
158
159 // open the temp file (strName is the name of file to be replaced)
160 bool Open(const wxString& strName);
161
162 // is the file opened?
163 bool IsOpened() const { return m_file.IsOpened(); }
164
165 // I/O (both functions return true on success, false on failure)
166 bool Write(const void *p, size_t n) { return m_file.Write(p, n) != 0; }
167 bool Write(const wxString& str, wxMBConv& conv = wxConvLibc) { return m_file.Write(str, conv); }
168
169 // different ways to close the file
170 // validate changes and delete the old file of name m_strName
171 bool Commit();
172 // discard changes
173 void Discard();
174
175 // dtor calls Discard() if file is still opened
176 ~wxTempFile();
177
178 private:
179 // no copy ctor/assignment operator
180 wxTempFile(const wxTempFile&);
181 wxTempFile& operator=(const wxTempFile&);
182
183 wxString m_strName, // name of the file to replace in Commit()
184 m_strTemp; // temporary file name
185 wxFile m_file; // the temporary file
186 };
187
188 #endif // wxUSE_FILE
189
190 #endif // _WX_FILEH__