added and documented wxDirTraverser::OnOpenError

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18895 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -16,6 +16,7 @@ All:
 - added wxDateSpan::operator==() and !=() (Lukasz Michalski)
 - use true/false throughout the library instead of TRUE/FALSE
 - wxStopWatch::Start() resumes the stop watch if paused, as per the docs
+- added wxDirTraverser::OnOpenError() to customize the error handling
 
 wxBase:
 

docs/latex/wx/dirtrav.tex

@@ -71,14 +71,6 @@ enum wxDirTraverseResult
 
 \latexignore{\rtfignore{\wxheading{Members}}}
 
-\membersection{wxDirTraverser::OnFile}\label{wxdirtraverseronfile}
-
-\func{virtual wxDirTraverseResult}{OnFile}{\param{const wxString\& }{filename}}
-
-This function is called for each file. It may return {\tt wxDIR\_STOP} to abort
-traversing (for example, if the file being searched is found) or 
-{\tt wxDIR\_CONTINUE} to proceed.
-
 \membersection{wxDirTraverser::OnDir}\label{wxdirtraverserondir}
 
 \func{virtual wxDirTraverseResult}{OnDir}{\param{const wxString\& }{dirname}}
@@ -88,4 +80,27 @@ to abort traversing completely, {\tt wxDIR\_IGNORE} to skip this directory but
 continue with others or {\tt wxDIR\_CONTINUE} to enumerate all files and
 subdirectories in this directory.
 
+This is a pure virtual function and must be implemented in the derived class.
+
+\membersection{wxDirTraverser::OnFile}\label{wxdirtraverseronfile}
+
+\func{virtual wxDirTraverseResult}{OnFile}{\param{const wxString\& }{filename}}
+
+This function is called for each file. It may return {\tt wxDIR\_STOP} to abort
+traversing (for example, if the file being searched is found) or 
+{\tt wxDIR\_CONTINUE} to proceed.
+
+This is a pure virtual function and must be implemented in the derived class.
+
+\membersection{wxOpenErrorTraverser::OnOpenError}\label{wxopenerrortraverseronopenerror}
+
+\func{virtual wxOpenErrorTraverseResult}{OnOpenError}{\param{const wxString\& }{openerrorname}}
+
+This function is called for each directory which we failed to open for
+enumerating. It may return {\tt wxSIR\_STOP} to abort traversing completely,
+{\tt wxDIR\_IGNORE} to skip this directory but continue with others or 
+{\tt wxDIR\_CONTINUE} to retry opening this directory once again.
+
+The base class version always returns {\tt wxDIR\_IGNORE}.
+
 

include/wx/dir.h

@@ -54,13 +54,25 @@ class WXDLLEXPORT wxDirTraverser
 public:
     // called for each file found by wxDir::Traverse()
     //
-    // return wxDIR_STOP or wxDIR_CONTINUE from here
+    // return wxDIR_STOP or wxDIR_CONTINUE from here (wxDIR_IGNORE doesn't
+    // make sense)
     virtual wxDirTraverseResult OnFile(const wxString& filename) = 0;
 
     // called for each directory found by wxDir::Traverse()
     //
     // return one of the enum elements defined above
     virtual wxDirTraverseResult OnDir(const wxString& dirname) = 0;
+
+    // called for each directory which we couldn't open during our traversal
+    // of the directory tyree
+    //
+    // this method can also return either wxDIR_STOP, wxDIR_IGNORE or
+    // wxDIR_CONTINUE but the latter is treated specially: it means to retry
+    // opening the directory and so may lead to infinite loop if it is
+    // returned unconditionally, be careful with this!
+    //
+    // the base class version always returns wxDIR_IGNORE
+    virtual wxDirTraverseResult OnOpenError(const wxString& dirname);
 };
 
 // ----------------------------------------------------------------------------

src/common/dircmn.cpp

@@ -43,6 +43,16 @@
 // implementation
 // ============================================================================
 
+// ----------------------------------------------------------------------------
+// wxDirTraverser
+// ----------------------------------------------------------------------------
+
+wxDirTraverseResult
+wxDirTraverser::OnOpenError(const wxString& WXUNUSED(dirname))
+{
+    return wxDIR_IGNORE;
+}
+
 // ----------------------------------------------------------------------------
 // wxDir::HasFiles() and HasSubDirs()
 // ----------------------------------------------------------------------------
@@ -88,29 +98,75 @@ size_t wxDir::Traverse(wxDirTraverser& sink,
     if ( flags & wxDIR_DIRS )
     {
         wxString dirname;
-        bool cont = GetFirst(&dirname, _T(""), wxDIR_DIRS | wxDIR_HIDDEN);
+        for ( bool cont = GetFirst(&dirname, _T(""), wxDIR_DIRS | wxDIR_HIDDEN);
-        while ( cont )
+              cont;
+              cont = GetNext(&dirname) )
         {
-            wxDirTraverseResult res = sink.OnDir(prefix + dirname);
+            const wxString fulldirname = prefix + dirname;
 
-            if ( res == wxDIR_STOP )
+            switch ( sink.OnDir(fulldirname) )
-                break;
-
-            if ( res == wxDIR_CONTINUE )
             {
-                wxDir subdir(prefix + dirname);
+                default:
-                if ( subdir.IsOpened() )
+                    wxFAIL_MSG(_T("unexpected OnDir() return value") );
-                {
+                    // fall through
-                    nFiles += subdir.Traverse(sink, filespec, flags);
-                }
-            }
-            else
-            {
-                wxASSERT_MSG( res == wxDIR_IGNORE,
-                              _T("unexpected OnDir() return value") );
-            }
 
-            cont = GetNext(&dirname);
+                case wxDIR_STOP:
+                    cont = false;
+                    break;
+
+                case wxDIR_CONTINUE:
+                    {
+                        wxDir subdir;
+
+                        // don't give the error messages for the directories
+                        // which we can't open: there can be all sorts of good
+                        // reason for this (e.g. insufficient privileges) and
+                        // this shouldn't be treated as an error -- instead
+                        // let the user code decide what to do
+                        bool ok;
+                        do
+                        {
+                            wxLogNull noLog;
+                            ok = subdir.Open(fulldirname);
+                            if ( !ok )
+                            {
+                                // ask the user code what to do
+                                bool tryagain;
+                                switch ( sink.OnOpenError(fulldirname) )
+                                {
+                                    default:
+                                        wxFAIL_MSG(_T("unexpected OnOpenError() return value") );
+                                        // fall through
+
+                                    case wxDIR_STOP:
+                                        cont = false;
+                                        // fall through
+
+                                    case wxDIR_IGNORE:
+                                        tryagain = false;
+                                        break;
+
+                                    case wxDIR_CONTINUE:
+                                        tryagain = true;
+                                }
+
+                                if ( !tryagain )
+                                    break;
+                            }
+                        }
+                        while ( !ok );
+
+                        if ( ok )
+                        {
+                            nFiles += subdir.Traverse(sink, filespec, flags);
+                        }
+                    }
+                    break;
+
+                case wxDIR_IGNORE:
+                    // nothing to do
+                    ;
+            }
         }
     }