Enable shuffle mode

Co-authored-by: data-dude92 <60513060+data-dude92@users.noreply.github.com>

src/imageselector.cpp

@@ -8,46 +8,80 @@
 #include <iostream>
 #include <stdlib.h>     /* srand, rand */
 #include <time.h>       /* time */
-
+#include <algorithm>    // std::shuffle
+#include <random>       // std::default_random_engine
 
 ImageSelector::ImageSelector(std::unique_ptr<PathTraverser>& pathTraverser):
-    pathTraverser(pathTraverser)
+  pathTraverser(pathTraverser)
 {
 }
 
 ImageSelector::~ImageSelector(){}
 
-DefaultImageSelector::DefaultImageSelector(std::unique_ptr<PathTraverser>& pathTraverser):
-    ImageSelector(pathTraverser)
+RandomImageSelector::RandomImageSelector(std::unique_ptr<PathTraverser>& pathTraverser):
+  ImageSelector(pathTraverser)
 {
-    srand (time(NULL));
+  srand (time(NULL));
 }
 
-DefaultImageSelector::~DefaultImageSelector(){}
+RandomImageSelector::~RandomImageSelector(){}
 
-std::string DefaultImageSelector::getNextImage() const
+std::string RandomImageSelector::getNextImage()
 {
-    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;
+  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;
 }
 
-unsigned int DefaultImageSelector::selectRandom(const QStringList& images) const
+unsigned int RandomImageSelector::selectRandom(const QStringList& images) const
 {
-    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();
+  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());
+  std::cout << "updating image: " << filename << std::endl;
+  current_image_shuffle = current_image_shuffle + 1;
+  return filename;
 }