Move source files to src directory

src/histogram.h

@@ -0,0 +1,22 @@
+#ifndef HISTOGRAM_H
+#define HISTOGRAM_H
+
+#include <QWidget>
+#include "imageringlist.h"
+
+class Histogram : public QWidget
+{
+    Q_OBJECT
+    std::vector<uint32_t> m_histogram;
+    std::vector<float> m_points;
+    bool m_log = false;
+public:
+    explicit Histogram(QWidget *parent = nullptr);
+public slots:
+    void imageLoaded(Image *img);
+protected:
+    void paintEvent(QPaintEvent *) override;
+    void mouseReleaseEvent(QMouseEvent *) override;
+};
+
+#endif // HISTOGRAM_H