Improve wxDir::Traverse() documentation.
[wxWidgets.git] / interface / wx / dir.h
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: dir.h
3 // Purpose: interface of wxDir and wxDirTraverser
4 // Author: wxWidgets team
5 // RCS-ID: $Id$
6 // Licence: wxWindows licence
7 /////////////////////////////////////////////////////////////////////////////
8
9 /**
10 Possible return values of wxDirTraverser callback functions.
11 */
12 enum wxDirTraverseResult
13 {
14 wxDIR_IGNORE = -1, ///< Ignore this directory but continue with others.
15 wxDIR_STOP, ///< Stop traversing.
16 wxDIR_CONTINUE ///< Continue into this directory.
17 };
18
19 /**
20 @class wxDirTraverser
21
22 wxDirTraverser is an abstract interface which must be implemented by
23 objects passed to wxDir::Traverse() function.
24
25 Example of use (this works almost like wxDir::GetAllFiles()):
26
27 @code
28 class wxDirTraverserSimple : public wxDirTraverser
29 {
30 public:
31 wxDirTraverserSimple(wxArrayString& files) : m_files(files) { }
32
33 virtual wxDirTraverseResult OnFile(const wxString& filename)
34 {
35 m_files.Add(filename);
36 return wxDIR_CONTINUE;
37 }
38
39 virtual wxDirTraverseResult OnDir(const wxString& WXUNUSED(dirname))
40 {
41 return wxDIR_CONTINUE;
42 }
43
44 private:
45 wxArrayString& m_files;
46 };
47
48 // get the names of all files in the array
49 wxArrayString files;
50 wxDirTraverserSimple traverser(files);
51
52 wxDir dir(dirname);
53 dir.Traverse(traverser);
54 @endcode
55
56 @library{wxbase}
57 @category{file}
58 */
59 class wxDirTraverser
60 {
61 public:
62 /**
63 This function is called for each directory. It may return ::wxDIR_STOP
64 to abort traversing completely, ::wxDIR_IGNORE to skip this directory
65 but continue with others or ::wxDIR_CONTINUE to enumerate all files and
66 subdirectories in this directory.
67
68 This is a pure virtual function and must be implemented in the derived
69 class.
70 */
71 virtual wxDirTraverseResult OnDir(const wxString& dirname) = 0;
72
73 /**
74 This function is called for each file. It may return ::wxDIR_STOP to
75 abort traversing (for example, if the file being searched is found) or
76 ::wxDIR_CONTINUE to proceed.
77
78 This is a pure virtual function and must be implemented in the derived
79 class.
80 */
81 virtual wxDirTraverseResult OnFile(const wxString& filename) = 0;
82
83 /**
84 This function is called for each directory which we failed to open for
85 enumerating. It may return ::wxDIR_STOP to abort traversing completely,
86 ::wxDIR_IGNORE to skip this directory but continue with others or
87 ::wxDIR_CONTINUE to retry opening this directory once again.
88
89 The base class version always returns ::wxDIR_IGNORE.
90 */
91 virtual wxDirTraverseResult OnOpenError(const wxString& openerrorname);
92 };
93
94
95
96 /**
97 These flags define what kind of filenames are included in the list of files
98 enumerated by wxDir::GetFirst() and wxDir::GetNext().
99 */
100 enum wxDirFlags
101 {
102 wxDIR_FILES = 0x0001, ///< Includes files.
103 wxDIR_DIRS = 0x0002, ///< Includes directories.
104 wxDIR_HIDDEN = 0x0004, ///< Includes hidden files.
105 wxDIR_DOTDOT = 0x0008, ///< Includes "." and "..".
106
107 //! Combination of the @c wxDIR_FILES, @c wxDIR_DIRS, @c wxDIR_HIDDEN flags
108 //! defined above.
109 wxDIR_DEFAULT = wxDIR_FILES | wxDIR_DIRS | wxDIR_HIDDEN
110 };
111
112 /**
113 @class wxDir
114
115 wxDir is a portable equivalent of Unix open/read/closedir functions which
116 allow enumerating of the files in a directory. wxDir allows to enumerate
117 files as well as directories.
118
119 wxDir also provides a flexible way to enumerate files recursively using
120 Traverse() or a simpler GetAllFiles() function.
121
122 Example of use:
123
124 @code
125 wxDir dir(wxGetCwd());
126
127 if ( !dir.IsOpened() )
128 {
129 // deal with the error here - wxDir would already log an error message
130 // explaining the exact reason of the failure
131 return;
132 }
133
134 puts("Enumerating object files in current directory:");
135
136 wxString filename;
137
138 bool cont = dir.GetFirst(&filename, filespec, flags);
139 while ( cont )
140 {
141 printf("%s\n", filename.c_str());
142
143 cont = dir.GetNext(&filename);
144 }
145 @endcode
146
147 @library{wxbase}
148 @category{file}
149 */
150 class wxDir
151 {
152 public:
153 /**
154 Default constructor, use Open() afterwards.
155 */
156 wxDir();
157 /**
158 Opens the directory for enumeration, use IsOpened() to test for errors.
159 */
160 wxDir(const wxString& dir);
161
162 /**
163 Destructor cleans up the associated resources. It is not virtual and so
164 this class is not meant to be used polymorphically.
165 */
166 ~wxDir();
167
168 /**
169 Test for existence of a directory with the given name.
170 */
171 static bool Exists(const wxString& dir);
172
173 /**
174 The function returns the path of the first file matching the given
175 @a filespec or an empty string if there are no files matching it.
176
177 The @a flags parameter may or may not include ::wxDIR_FILES, the
178 function always behaves as if it were specified. By default, @a flags
179 includes ::wxDIR_DIRS and so the function recurses into the
180 subdirectories but if this flag is not specified, the function
181 restricts the search only to the directory @a dirname itself.
182 See ::wxDirFlags for the list of the possible flags.
183
184 @see Traverse()
185 */
186 static wxString FindFirst(const wxString& dirname,
187 const wxString& filespec,
188 int flags = wxDIR_DEFAULT);
189
190 /**
191 The function appends the names of all the files under directory
192 @a dirname to the array @a files (note that its old content is
193 preserved). Only files matching the @a filespec are taken, with empty
194 spec matching all the files.
195
196 The @a flags parameter should always include ::wxDIR_FILES or the array
197 would be unchanged and should include ::wxDIR_DIRS flag to recurse into
198 subdirectories (both flags are included in the value by default).
199 See ::wxDirFlags for the list of the possible flags.
200
201 @return Returns the total number of files found while traversing
202 the directory @a dirname (i.e. the number of entries appended
203 to the @a files array).
204
205 @see Traverse()
206 */
207 static size_t GetAllFiles(const wxString& dirname, wxArrayString* files,
208 const wxString& filespec = wxEmptyString,
209 int flags = wxDIR_DEFAULT);
210
211 /**
212 Start enumerating all files matching @a filespec (or all files if it is
213 empty) and @e flags, return @true on success.
214 See ::wxDirFlags for the list of the possible flags.
215 */
216 bool GetFirst(wxString* filename,
217 const wxString& filespec = wxEmptyString,
218 int flags = wxDIR_DEFAULT) const;
219
220 /**
221 Returns the name of the directory itself.
222
223 The returned string does not have the trailing path separator (slash or
224 backslash).
225
226 Notice that in spite of this the last character of the returned string
227 can still be the path separator if this directory is the root one.
228 Because of this, don't append ::wxFILE_SEP_PATH to the returned value
229 if you do need a slash-terminated directory name but use
230 GetNameWithSep() instead to avoid having duplicate consecutive slashes.
231 */
232 wxString GetName() const;
233
234 /**
235 Returns the name of the directory with the path separator appended.
236
237 The last character of the returned string is always ::wxFILE_SEP_PATH
238 unless the string is empty, indicating that this directory is invalid.
239
240 @see GetName()
241
242 @since 2.9.4
243 */
244 wxString GetNameWithSep() const;
245
246 /**
247 Continue enumerating files which satisfy the criteria specified by the
248 last call to GetFirst().
249 */
250 bool GetNext(wxString* filename) const;
251
252 /**
253 Returns the size (in bytes) of all files recursively found in @c dir or
254 @c wxInvalidSize in case of error.
255
256 In case it happens that while traversing folders a file's size cannot
257 be read, that file is added to the @a filesSkipped array, if not @NULL,
258 and then skipped. This usually happens with some special folders which
259 are locked by the operating system or by another process. Remember that
260 when the size of @a filesSkipped is not zero, then the returned value
261 is not 100% accurate and, if the skipped files were big, it could be
262 far from real size of the directory.
263
264 @see wxFileName::GetHumanReadableSize(), wxGetDiskSpace()
265 */
266 static wxULongLong GetTotalSize(const wxString& dir,
267 wxArrayString* filesSkipped = NULL);
268
269 /**
270 Returns @true if the directory contains any files matching the given
271 @a filespec. If @a filespec is empty, look for any files at all. In any
272 case, even hidden files are taken into account.
273 */
274 bool HasFiles(const wxString& filespec = wxEmptyString) const;
275
276 /**
277 Returns @true if the directory contains any subdirectories (if a non
278 empty @a filespec is given, only check for directories matching it).
279 The hidden subdirectories are taken into account as well.
280 */
281 bool HasSubDirs(const wxString& dirspec = wxEmptyString) const;
282
283 /**
284 Returns @true if the directory was successfully opened by a previous
285 call to Open().
286 */
287 bool IsOpened() const;
288
289 /**
290 Creates a directory.
291
292 This is just an alias for wxFileName::Mkdir(); refer to that function
293 for more info.
294 */
295 static bool Make(const wxString &dir, int perm = wxS_DIR_DEFAULT,
296 int flags = 0);
297
298 /**
299 Open the directory for enumerating, returns @true on success or @false
300 if an error occurred.
301 */
302 bool Open(const wxString& dir);
303
304 /**
305 Removes a directory.
306
307 This is just an alias for wxFileName::Rmdir(); refer to that function
308 for more info.
309 */
310 static bool Remove(const wxString &dir, int flags = 0);
311
312 /**
313 Enumerate all files and directories under the given directory.
314
315 If @a flags contains ::wxDIR_DIRS this enumeration is recursive, i.e.
316 all the subdirectories of the given one and the files inside them will
317 be traversed. Otherwise only the files in this directory itself are.
318
319 If @a flags doesn't contain ::wxDIR_FILES then only subdirectories are
320 examined but not normal files. It doesn't make sense to not specify
321 either ::wxDIR_DIRS or ::wxDIR_FILES and usually both of them should be
322 specified, as is the case by default.
323
324 For each directory found, @ref wxDirTraverser::OnDir() "sink.OnDir()"
325 is called and @ref wxDirTraverser::OnFile() "sink.OnFile()" is called
326 for every file. Depending on the return value, the enumeration may
327 continue or stop. If entering a subdirectory fails, @ref
328 wxDirTraverser::OnOpenError() "sink.OnOpenError()" is called.
329
330 The function returns the total number of files found or @c "(size_t)-1"
331 on error.
332
333 See ::wxDirFlags for the full list of the possible flags.
334
335 @see GetAllFiles()
336 */
337 size_t Traverse(wxDirTraverser& sink,
338 const wxString& filespec = wxEmptyString,
339 int flags = wxDIR_DEFAULT) const;
340 };
341