refs #585, utility function to make directory path relative and find first file existing

src/blackmisc/fileutils.cpp

@@ -121,6 +121,26 @@ namespace BlackMisc
         return n;
     }
 
+    QStringList CFileUtils::makeDirectoriesRelative(const QStringList &directories, const QString &rootDirectory, Qt::CaseSensitivity cs)
+    {
+        if (rootDirectory.isEmpty() || rootDirectory == "/") { return directories; }
+        const QString rd(rootDirectory.endsWith('/') ? rootDirectory.left(rootDirectory.length() - 1) : rootDirectory);
+        const int p = rd.length();
+        QStringList relativeDirectories;
+        for (const QString &dir : directories)
+        {
+            if (dir.startsWith(rd, cs) && dir.length() > p + 1)
+            {
+                relativeDirectories.append(dir.mid(p + 1));
+            }
+            else
+            {
+                relativeDirectories.append(dir); // absolute
+            }
+        }
+        return relativeDirectories;
+    }
+
     Qt::CaseSensitivity CFileUtils::osFileNameCaseSensitivity()
     {
         return CBuildConfig::isRunningOnWindowsNtPlatform() ? Qt::CaseInsensitive : Qt::CaseSensitive;
@@ -159,6 +179,19 @@ namespace BlackMisc
         return false;
     }
 
+    QString CFileUtils::findFirstExisting(const QStringList &filesOrDirectory)
+    {
+        if (filesOrDirectory.isEmpty()) { return ""; }
+        for (const QString &f : filesOrDirectory)
+        {
+            if (f.isEmpty()) { continue; }
+            const QString fn(normalizeFilePathToQtStandard(f));
+            const QFileInfo fi(fn);
+            if (fi.exists()) { return fi.absoluteFilePath(); }
+        }
+        return "";
+    }
+
     QString CFileUtils::findFirstFile(const QDir &dir, bool recursive, const QStringList &nameFilters, const QStringList &excludeDirectories, std::function<bool(const QFileInfo &)> predicate)
     {
         if (isExcludedDirectory(dir, excludeDirectories)) { return QString(); }

src/blackmisc/fileutils.h

@@ -61,6 +61,9 @@ namespace BlackMisc
         //! Normalize file path to Qt standard, e.g by turning \ to /
         static QString normalizeFilePathToQtStandard(const QString &filePath);
 
+        //! Make directory paths relative to root directory
+        static QStringList makeDirectoriesRelative(const QStringList &directories, const QString &rootDirectory, Qt::CaseSensitivity cs = osFileNameCaseSensitivity());
+
         //! Case sensitivity for current OS
         static Qt::CaseSensitivity osFileNameCaseSensitivity();
 
@@ -76,6 +79,9 @@ namespace BlackMisc
         //! Directory to be excluded?
         static bool isExcludedDirectory(const QString &directoryPath, const QStringList &excludeDirectories, Qt::CaseSensitivity cs = osFileNameCaseSensitivity());
 
+        //! Find first existing file or directory
+        static QString findFirstExisting(const QStringList &filesOrDirectory);
+
         //! Returns path to first file in dir which matches the optional wildcard and predicate, or empty string.
         static QString findFirstFile(const QDir &dir, bool recursive, const QStringList &nameFilters = {}, const QStringList &excludeDirectories = {}, std::function<bool(const QFileInfo &)> predicate = {});