Directory monitoring works via file names instead of paths

- ContentManager::m_knownZimFiles[dirPath] now stores filenames (rather
  than full paths) of known ZIM files in directory at dirPath.

- Library::getLibraryZimsFromDir() returns a set of file names (rather
  than paths)

Note that the change of the semantics of ContentManager::m_knownZimFiles
has been carried out via the change in the value of the second argument
of ContentManager::setMonitorDirZims():

1. In KiwixApp::setupDirectoryMonitoring() the latter is fed with the
   output of (the now changed) Library::getLibraryZimsFromDir()

2. In ContentManager::updateLibraryFromDir() all variables representing
   a set of files now contain filenames only (note that
   ContentManager::handleNewZimFiles() returns just a subset of its second
   parameter) and therefore produce a set of filenames.

src/contentmanager.cpp

@@ -864,10 +864,11 @@ void ContentManager::asyncUpdateLibraryFromDir(QString dir)
     });
 }
 
-void ContentManager::handleDisappearedZimFiles(const QStringSet& zimPaths)
+void ContentManager::handleDisappearedZimFiles(const QString& dirPath, const QStringSet& fileNames)
 {
     const auto kiwixLib = mp_library->getKiwixLibrary();
-    for (auto bookPath : zimPaths) {
+    for (const auto& file : fileNames) {
+        const auto bookPath = QDir::toNativeSeparators(dirPath + "/" + file);
         try {
             DBGOUT("directory monitoring: file disappeared: " << bookPath);
             const auto book = kiwixLib->getBookByPath(bookPath.toStdString());
@@ -879,18 +880,19 @@ void ContentManager::handleDisappearedZimFiles(const QStringSet& zimPaths)
     }
 }
 
-ContentManager::QStringSet ContentManager::handleNewZimFiles(const QStringSet& zimPaths)
+ContentManager::QStringSet ContentManager::handleNewZimFiles(const QString& dirPath, const QStringSet& fileNames)
 {
     QStringSet successfullyAddedZims;
     const auto kiwixLib = mp_library->getKiwixLibrary();
     kiwix::Manager manager(kiwixLib);
-    for (auto bookPath : zimPaths) {
+    for (const auto& file : fileNames) {
+        const auto bookPath = QDir::toNativeSeparators(dirPath + "/" + file);
         DBGOUT("directory monitoring: file appeared: " << bookPath);
         if ( mp_library->isBeingDownloadedByUs(bookPath) ) {
             DBGOUT("                      it is being downloaded by us, ignoring...");
         } else if ( manager.addBookFromPath(bookPath.toStdString()) ) {
             DBGOUT("                      and was added to the library");
-            successfullyAddedZims.insert(bookPath);
+            successfullyAddedZims.insert(file);
         } else {
             DBGOUT("                      but could not be added to the library");
         }
@@ -906,13 +908,13 @@ void ContentManager::updateLibraryFromDir(QString dirPath)
 
     QStringSet zimsInDir;
     for (const auto &file : dir.entryList({"*.zim"})) {
-        zimsInDir.insert(QDir::toNativeSeparators(dirPath + "/" + file));
+        zimsInDir.insert(file);
     }
 
     const QStringSet zimsNotInLib = zimsInDir - zimsPresentInLib;
     const QStringSet removedZims = zimsPresentInLib - zimsInDir;
-    handleDisappearedZimFiles(removedZims);
-    const auto successfullyAddedZims = handleNewZimFiles(zimsNotInLib);
+    handleDisappearedZimFiles(dirPath, removedZims);
+    const auto successfullyAddedZims = handleNewZimFiles(dirPath, zimsNotInLib);
     if (!removedZims.empty() || !successfullyAddedZims.empty()) {
         mp_library->save();
         emit(booksChanged());

src/contentmanager.h

@@ -118,8 +118,8 @@ private: // functions
     void setCategories();
     void setLanguages();
     void updateLibraryFromDir(QString dir);
-    void handleDisappearedZimFiles(const QStringSet& zimPaths);
-    QStringSet handleNewZimFiles(const QStringSet& zimPaths);
+    void handleDisappearedZimFiles(const QString& dirPath, const QStringSet& fileNames);
+    QStringSet handleNewZimFiles(const QString& dirPath, const QStringSet& fileNames);
     void handleDisappearedZimFile(QString bookId);
 
     // Get the book with the specified id from

src/library.cpp

@@ -201,9 +201,9 @@ Library::QStringSet Library::getLibraryZimsFromDir(QString dir) const
         auto filePath = QString::fromStdString(getBookById(str).getPath());
         if ( filePath.endsWith(BEINGDOWNLOADEDSUFFIX) )
                 continue;
-        QDir absoluteDir = QFileInfo(filePath).absoluteDir();
-        if (absoluteDir == dir) {
-            zimsInDir.insert(filePath);
+        const QFileInfo fileInfo(filePath);
+        if (fileInfo.absoluteDir() == dir) {
+            zimsInDir.insert(fileInfo.fileName());
         }
     }
     return zimsInDir;