refactor image filtering

src/imageselector.cpp

@@ -50,6 +50,28 @@ int ImageSelector::getImageRotation(const std::string &fileName)
   return degrees;
 }
 
+bool ImageSelector::imageMatchesFilter(const std::string& fileName)
+{
+  if(!QFileInfo::exists(QString(fileName.c_str())))
+  {
+    if(debugMode)
+    {
+      std::cout << "file not found: " << fileName << std::endl;
+    }
+    return false;
+  }
+
+  if(!imageValidForAspect(fileName)) {
+    if(debugMode)
+    {
+      std::cout << "image aspect ratio doesn't match filter '" << aspect << "' : " << fileName << std::endl;
+    }
+    return false;
+  }
+
+  return true;
+}
+
 bool ImageSelector::imageValidForAspect(const std::string& fileName)
 {
   QPixmap p( fileName.c_str() );
@@ -95,19 +117,16 @@ std::string RandomImageSelector::getNextImage()
 {
   std:: string filename;
   try
-  {
-    while (filename.empty())
   {
     QStringList images = pathTraverser->getImages();
     unsigned int selectedImage = selectRandom(images);
     filename = pathTraverser->getImagePath(images.at(selectedImage).toStdString());
-      if (!imageValidForAspect(filename))
+    while(!imageMatchesFilter(filename))
     {
-        filename.clear();
+      unsigned int selectedImage = selectRandom(images);
+      filename = pathTraverser->getImagePath(images.at(selectedImage).toStdString());
     }
   }
-
-  }
   catch(const std::string& err) 
   {
     std::cerr << "Error: " << err << std::endl;
@@ -142,6 +161,24 @@ ShuffleImageSelector::~ShuffleImageSelector()
 }
 
 std::string ShuffleImageSelector::getNextImage()
+{
+  reloadImagesIfNoneLeft();
+  if (images.size() == 0)
+  {
+    return "";
+  }
+  std::string filename = pathTraverser->getImagePath(images.at(current_image_shuffle).toStdString());
+  current_image_shuffle = current_image_shuffle + 1; // ignore and move to next image
+  while(!imageMatchesFilter(filename)) {
+    reloadImagesIfNoneLeft();
+    std::string filename = pathTraverser->getImagePath(images.at(current_image_shuffle).toStdString());
+    current_image_shuffle = current_image_shuffle + 1; // ignore and move to next image
+  }
+  std::cout << "updating image: " << filename << std::endl;
+  return filename;
+}
+
+void ShuffleImageSelector::reloadImagesIfNoneLeft()
 {
   if (images.size() == 0 || current_image_shuffle >= images.size())
   {
@@ -152,32 +189,6 @@ std::string ShuffleImageSelector::getNextImage()
     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())))
-  {
-    if(debugMode)
-    {
-      std::cout << "file not found: " << filename << std::endl;
-    }
-    current_image_shuffle = current_image_shuffle + 1; // ignore and move to next image
-    return getNextImage();
-  }
-  if (!imageValidForAspect(filename))
-  {
-    if(debugMode)
-    {
-      std::cout << "image has invalid aspect: " << filename << "(images left:" << (images.size()-current_image_shuffle) << ")" << std::endl;
-    }
-    current_image_shuffle = current_image_shuffle + 1; // ignore and move to next image
-    return getNextImage();
-  }
-  std::cout << "updating image: " << filename << std::endl;
-  current_image_shuffle = current_image_shuffle + 1;
-  return filename;
 }
 
 SortedImageSelector::SortedImageSelector(std::unique_ptr<PathTraverser>& pathTraverser, char aspect):
@@ -204,6 +215,23 @@ bool operator<(const QString& lhs, const QString& rhs) noexcept{
 }
 
 std::string SortedImageSelector::getNextImage()
+{
+  reloadImagesIfEmpty();
+  if (images.size() == 0)
+  {
+    return "";
+  }
+  std::string filename = pathTraverser->getImagePath(images.takeFirst().toStdString());
+  while(!imageMatchesFilter(filename)) {
+    reloadImagesIfEmpty();
+    filename = pathTraverser->getImagePath(images.takeFirst().toStdString());
+  }
+
+  std::cout << "updating image: " << filename << std::endl;
+  return filename;
+}
+
+void SortedImageSelector::reloadImagesIfEmpty()
 {
   if (images.size() == 0)
   {
@@ -213,33 +241,8 @@ std::string SortedImageSelector::getNextImage()
     {
       std::cout << "read " << images.size() << " images." << std::endl;
       for (int i = 0;i <images.size();i++){
-        
           std::cout << images[i].toStdString() << std::endl;
       }
     }
   }
-  if (images.size() == 0)
-  {
-    return "";
-  }
-  std::string filename = pathTraverser->getImagePath(images.takeFirst().toStdString());
-  if(!QFileInfo::exists(QString(filename.c_str())))
-  {
-    if(debugMode)
-    {
-      std::cout << "file not found: " << filename << std::endl;
-    }
-    return getNextImage();
-  }
-  if (!imageValidForAspect(filename))
-  {
-    if(debugMode)
-    {
-      std::cout << "image has invalid aspect: " << filename << std::endl;
-    }
-    return getNextImage();
-  }
-
-  std::cout << "updating image: " << filename << std::endl;
-  return filename;
 }

src/imageselector.h

@@ -18,6 +18,7 @@ public:
 
 protected:
     int getImageRotation(const std::string& fileName);
+    bool imageMatchesFilter(const std::string& fileName);
     bool imageValidForAspect(const std::string& fileName);
     std::unique_ptr<PathTraverser>& pathTraverser;
     char aspect;
@@ -43,6 +44,7 @@ public:
     virtual std::string getNextImage();
 
 private:
+    void reloadImagesIfNoneLeft();
     int current_image_shuffle;
     QStringList images;
 };
@@ -55,6 +57,7 @@ public:
     virtual std::string getNextImage();
 
 private:
+    void reloadImagesIfEmpty();
     QStringList images;
 };
 #endif // IMAGESELECTOR_H