diff --git a/README.md b/README.md
index e4f14b5..4e47f19 100644
--- a/README.md
+++ b/README.md
@@ -46,3 +46,16 @@ qmake ../src/slide.pro
 make
 sudo make install
 ```
+
+### macOS
+
+Prerequisite: brew
+
+```
+brew install qt5
+brew install libexif
+mkdir -p build
+cd build
+qmake ../src/slide.pro
+make
+```
diff --git a/src/imageselector.cpp b/src/imageselector.cpp
index 5f9261b..12f68a0 100644
--- a/src/imageselector.cpp
+++ b/src/imageselector.cpp
@@ -1,4 +1,5 @@
 #include "imageselector.h"
+#include "pathtraverser.h"
 #include "mainwindow.h"
 #include <QDirIterator>
 #include <QTimer>
@@ -7,59 +8,86 @@
 #include <iostream>
 #include <stdlib.h>     /* srand, rand */
 #include <time.h>       /* time */
+#include <algorithm>    // std::shuffle
+#include <random>       // std::default_random_engine
 
-ImageSelector::ImageSelector(std::string path, bool recursive):
-    path(path),
-    recursive(recursive)
+ImageSelector::ImageSelector(std::unique_ptr<PathTraverser>& pathTraverser):
+  pathTraverser(pathTraverser)
 {
-    srand (time(NULL));
 }
 
-std::string ImageSelector::getNextImage() const
+ImageSelector::~ImageSelector(){}
+
+RandomImageSelector::RandomImageSelector(std::unique_ptr<PathTraverser>& pathTraverser):
+  ImageSelector(pathTraverser)
 {
-    QDir directory(path.c_str());
-    std:: string filename;
-    try
-    {
-      if (recursive)
-      {
-        QStringList images = listImagesRecursive();
-        unsigned int selectedImage = selectRandom(images);
-        filename = images.at(selectedImage).toStdString();
-      }
-      else
-      {
-        QStringList images = directory.entryList(QStringList() << "*.jpg" << "*.JPG", QDir::Files);
-        unsigned int selectedImage = selectRandom(images);
-        filename = directory.filePath(images.at(selectedImage)).toStdString();
-      }
-    }
-    catch(const std::string& err) 
-    {
-      std::cerr << "Error: " << err << std::endl;
-    }
-    std::cout << "updating image: " << filename << std::endl;
-    return filename;
+  srand (time(NULL));
 }
 
-unsigned int ImageSelector::selectRandom(const QStringList& images) const
+RandomImageSelector::~RandomImageSelector(){}
+
+std::string RandomImageSelector::getNextImage()
 {
-    std::cout << "images: " << images.size() << std::endl;
-    if (images.size() == 0)
-    {
-      throw std::string("No jpg images found in folder " + path);
-    }
-    return rand() % images.size();
+  std:: string filename;
+  try
+  {
+    QStringList images = pathTraverser->getImages();
+    unsigned int selectedImage = selectRandom(images);
+    filename = pathTraverser->getImagePath(images.at(selectedImage).toStdString());
+  }
+  catch(const std::string& err) 
+  {
+    std::cerr << "Error: " << err << std::endl;
+  }
+  std::cout << "updating image: " << filename << std::endl;
+  return filename;
 }
 
-
-QStringList ImageSelector::listImagesRecursive() const
+unsigned int RandomImageSelector::selectRandom(const QStringList& images) const
 {
-    QDirIterator it(QString(path.c_str()), QStringList() << "*.jpg" << "*.JPG", QDir::Files, QDirIterator::Subdirectories);
-    QStringList files;
-    while (it.hasNext())
-    {
-       files.append(it.next());
-    }
-    return files;
+  std::cout << "images: " << images.size() << std::endl;
+  if (images.size() == 0)
+  {
+    throw std::string("No jpg images found in given folder");
+  }
+  return rand() % images.size();
+}
+
+ShuffleImageSelector::ShuffleImageSelector(std::unique_ptr<PathTraverser>& pathTraverser):
+  ImageSelector(pathTraverser),
+  current_image_shuffle(-1),
+  images()
+{
+  srand (time(NULL));
+}
+
+ShuffleImageSelector::~ShuffleImageSelector()
+{
+}
+
+std::string ShuffleImageSelector::getNextImage()
+{
+  if (images.size() == 0 || current_image_shuffle >= images.size())
+  {
+    current_image_shuffle = 0;
+    images = pathTraverser->getImages();
+    std::cout << "Shuffling " << images.size() << " images." << std::endl;
+    std::random_device rd;
+    std::mt19937 randomizer(rd());
+    std::shuffle(images.begin(), images.end(), randomizer);
+  }
+  if (images.size() == 0)
+  {
+    return "";
+  }
+  std::string filename = pathTraverser->getImagePath(images.at(current_image_shuffle).toStdString());
+  if(!QFileInfo::exists(QString(filename.c_str())))
+  {
+    std::cout << "file not found: " << filename << std::endl;
+    current_image_shuffle = images.size();
+    return getNextImage();
+  }
+  std::cout << "updating image: " << filename << std::endl;
+  current_image_shuffle = current_image_shuffle + 1;
+  return filename;
 }
diff --git a/src/imageselector.h b/src/imageselector.h
index 2a5b2c7..b01d662 100644
--- a/src/imageselector.h
+++ b/src/imageselector.h
@@ -2,20 +2,44 @@
 #define IMAGESELECTOR_H
 
 #include <iostream>
+#include <memory>
 #include <QStringList>
 
 class MainWindow;
+class PathTraverser;
+
 class ImageSelector
 {
 public:
-    ImageSelector(std::string path, bool recursive);
-    std::string getNextImage() const;
+    ImageSelector(std::unique_ptr<PathTraverser>& pathTraverser);
+    virtual ~ImageSelector();
+    virtual std::string getNextImage() = 0;
+
+protected:
+    std::unique_ptr<PathTraverser>& pathTraverser;
+};
+
+class RandomImageSelector : public ImageSelector
+{
+public:
+    RandomImageSelector(std::unique_ptr<PathTraverser>& pathTraverser);
+    virtual ~RandomImageSelector();
+    virtual std::string getNextImage();
 
 private:
-    QStringList listImagesRecursive() const;
     unsigned int selectRandom(const QStringList& images) const;
-    std::string path;
-    bool recursive;
+};
+
+class ShuffleImageSelector : public ImageSelector
+{
+public:
+    ShuffleImageSelector(std::unique_ptr<PathTraverser>& pathTraverser);
+    virtual ~ShuffleImageSelector();
+    virtual std::string getNextImage();
+
+private:
+    int current_image_shuffle;
+    QStringList images;
 };
 
 #endif // IMAGESELECTOR_H
diff --git a/src/imageswitcher.cpp b/src/imageswitcher.cpp
index ea9753a..e64979d 100644
--- a/src/imageswitcher.cpp
+++ b/src/imageswitcher.cpp
@@ -4,12 +4,12 @@
 #include <QDirIterator>
 #include <QTimer>
 #include <QApplication>
-#include <QDir>
 #include <iostream>
+#include <memory>
 #include <stdlib.h>     /* srand, rand */
 #include <time.h>       /* time */
 
-ImageSwitcher::ImageSwitcher(MainWindow& w, unsigned int timeout, const ImageSelector& selector):
+ImageSwitcher::ImageSwitcher(MainWindow& w, unsigned int timeout, std::unique_ptr<ImageSelector>& selector):
     QObject::QObject(),
     window(w),
     timeout(timeout),
@@ -20,7 +20,7 @@ ImageSwitcher::ImageSwitcher(MainWindow& w, unsigned int timeout, const ImageSel
 
 void ImageSwitcher::updateImage()
 {
-    std::string filename(selector.getNextImage());
+    std::string filename(selector->getNextImage());
     if (filename == "")
     {
       window.warn("No image found.");
diff --git a/src/imageswitcher.h b/src/imageswitcher.h
index 8c6b027..d49d3ad 100644
--- a/src/imageswitcher.h
+++ b/src/imageswitcher.h
@@ -4,6 +4,7 @@
 #include <QObject>
 #include <QTimer>
 #include <iostream>
+#include <memory>
 
 class MainWindow;
 class ImageSelector;
@@ -11,7 +12,7 @@ class ImageSwitcher : public QObject
 {
     Q_OBJECT
 public:
-    ImageSwitcher(MainWindow& w, unsigned int timeout, const ImageSelector& selector);
+    ImageSwitcher(MainWindow& w, unsigned int timeout, std::unique_ptr<ImageSelector>& selector);
     void start();
 
 public slots:
@@ -19,7 +20,7 @@ public slots:
 private:
     MainWindow& window;
     unsigned int timeout;
-    const ImageSelector& selector;
+    std::unique_ptr<ImageSelector>& selector;
     QTimer timer;
 };
 
diff --git a/src/main.cpp b/src/main.cpp
index a922eab..e7c0a7e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,6 +1,7 @@
 #include "mainwindow.h"
 #include "imageselector.h"
 #include "imageswitcher.h"
+#include "pathtraverser.h"
 #include <QApplication>
 #include <iostream>
 #include <sys/file.h>
@@ -9,6 +10,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <memory>
 
 void usage(std::string programName) {
     std::cerr << "Usage: " << programName << " [-t rotation_seconds] [-o background_opacity(0..255)] [-b blur_radius] -p image_folder -r" << std::endl;
@@ -16,46 +18,72 @@ void usage(std::string programName) {
 
 int main(int argc, char *argv[])
 {
-    unsigned int rotationSeconds = 30;
-    std::string path = "";
+  unsigned int rotationSeconds = 30;
+  std::string path = "";
 
-    QApplication a(argc, argv);
+  QApplication a(argc, argv);
 
-    MainWindow w;
-    int opt;
-    bool recursive = false;
-    while ((opt = getopt(argc, argv, "b:p:t:o:r")) != -1) {
-        switch (opt) {
-        case 'p':
-            path = optarg;
-            break;
-        case 't':
-            rotationSeconds = atoi(optarg);
-            break;
-        case 'b':
-            w.setBlurRadius(atoi(optarg));
-            break;
-        case 'o':
-            w.setBackgroundOpacity(atoi(optarg));
-            break;
-        case 'r':
-            recursive = true;
-            break;
-        default: /* '?' */
-            usage(argv[0]);
-            return 1;
-        }
-    }
-
-    if (path.empty()) {
-        std::cout << "Error: Path expected." << std::endl;
+  MainWindow w;
+  int opt;
+  bool recursive = false;
+  bool shuffle = false;
+  while ((opt = getopt(argc, argv, "b:p:t:o:rs")) != -1) {
+    switch (opt) {
+      case 'p':
+        path = optarg;
+        break;
+      case 't':
+        rotationSeconds = atoi(optarg);
+        break;
+      case 'b':
+        w.setBlurRadius(atoi(optarg));
+        break;
+      case 'o':
+        w.setBackgroundOpacity(atoi(optarg));
+        break;
+      case 'r':
+        recursive = true;
+        break;
+      case 's':
+        shuffle = true;
+        std::cout << "Shuffle mode is on." << std::endl;
+        break;
+      default: /* '?' */
         usage(argv[0]);
         return 1;
     }
-    w.show();
+  }
 
-    ImageSelector selector(path, recursive);
-    ImageSwitcher switcher(w, rotationSeconds * 1000, selector);
-    switcher.start();
-    return a.exec();
+  if (path.empty())
+  {
+    std::cout << "Error: Path expected." << std::endl;
+    usage(argv[0]);
+    return 1;
+  }
+
+  std::unique_ptr<PathTraverser> pathTraverser;
+  if (recursive)
+  {
+    pathTraverser = std::unique_ptr<PathTraverser>(new RecursivePathTraverser(path));
+  }
+  else
+  {
+    pathTraverser = std::unique_ptr<PathTraverser>(new DefaultPathTraverser(path));
+  }
+
+  std::unique_ptr<ImageSelector> selector;
+  if (shuffle)
+  {
+    selector = std::unique_ptr<ImageSelector>(new ShuffleImageSelector(pathTraverser));
+  }
+  else
+  {
+    selector = std::unique_ptr<ImageSelector>(new RandomImageSelector(pathTraverser));
+  }
+
+  w.show();
+
+  ImageSwitcher switcher(w, rotationSeconds * 1000, selector);
+  switcher.start();
+  return a.exec();
 }
diff --git a/src/pathtraverser.cpp b/src/pathtraverser.cpp
new file mode 100644
index 0000000..5686e25
--- /dev/null
+++ b/src/pathtraverser.cpp
@@ -0,0 +1,55 @@
+#include "pathtraverser.h"
+#include "mainwindow.h"
+#include <QDirIterator>
+#include <QTimer>
+#include <QApplication>
+#include <QDir>
+#include <iostream>
+#include <stdlib.h>     /* srand, rand */
+
+PathTraverser::PathTraverser(const std::string path):
+  path(path)
+{}
+
+PathTraverser::~PathTraverser() {}
+
+RecursivePathTraverser::RecursivePathTraverser(const std::string path):
+  PathTraverser(path)
+{}
+
+RecursivePathTraverser::~RecursivePathTraverser() {}
+
+
+QStringList RecursivePathTraverser::getImages() const
+{
+    QDirIterator it(QString(path.c_str()), QStringList() << "*.jpg" << "*.JPG", QDir::Files, QDirIterator::Subdirectories);
+    QStringList files;
+    while (it.hasNext())
+    {
+       files.append(it.next());
+    }
+    return files;
+}
+
+const std::string RecursivePathTraverser::getImagePath(const std::string image) const
+{
+  return image;
+}
+
+DefaultPathTraverser::DefaultPathTraverser(const std::string path):
+  PathTraverser(path),
+  directory(path.c_str())
+{}
+
+DefaultPathTraverser::~DefaultPathTraverser() {}
+
+
+QStringList DefaultPathTraverser::getImages() const
+{
+  return directory.entryList(QStringList() << "*.jpg" << "*.JPG", QDir::Files);
+}
+
+const std::string DefaultPathTraverser::getImagePath(const std::string image) const
+{
+  return directory.filePath(QString(image.c_str())).toStdString();
+}
diff --git a/src/pathtraverser.h b/src/pathtraverser.h
new file mode 100644
index 0000000..d400ce8
--- /dev/null
+++ b/src/pathtraverser.h
@@ -0,0 +1,41 @@
+#ifndef PATHTRAVERSER_H
+#define PATHTRAVERSER_H
+
+#include <iostream>
+#include <QDir>
+#include <QStringList>
+
+class MainWindow;
+class PathTraverser
+{
+  public:
+    PathTraverser(const std::string path);
+    virtual ~PathTraverser();
+    virtual QStringList getImages() const = 0;
+    virtual const std::string getImagePath(const std::string image) const = 0;
+
+  protected:
+    const std::string path;
+};
+
+class RecursivePathTraverser : public PathTraverser
+{
+  public:
+    RecursivePathTraverser(const std::string path);
+    virtual ~RecursivePathTraverser();
+    QStringList getImages() const;
+    virtual const std::string getImagePath(const std::string image) const;
+};
+
+class DefaultPathTraverser : public PathTraverser
+{
+  public:
+    DefaultPathTraverser(const std::string path);
+    virtual ~DefaultPathTraverser();
+    QStringList getImages() const;
+    virtual const std::string getImagePath(const std::string image) const;
+  private:
+    QDir directory;
+};
+
+#endif // PATHTRAVERSER_H
diff --git a/src/slide.pro b/src/slide.pro
index 906ba94..7f8c9ab 100644
--- a/src/slide.pro
+++ b/src/slide.pro
@@ -22,16 +22,22 @@ DEFINES += QT_DEPRECATED_WARNINGS
 # You can also select to disable deprecated APIs only up to a certain version of Qt.
 #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
 
+mac: INCLUDEPATH += $$system(brew --prefix libexif)/include/
+mac: QMAKE_LFLAGS += -L$$system(brew --prefix libexif)/lib
+
+
 
 SOURCES += \
         main.cpp \
         mainwindow.cpp \
         imageswitcher.cpp \
+        pathtraverser.cpp \
     imageselector.cpp
 
 HEADERS += \
         mainwindow.h \
         imageselector.h \
+        pathtraverser.h \
     imageswitcher.h
 
 FORMS += \