split switcher and traverser to prepare for shuffle mode

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