+// middle event box
+gboolean middle_event_box_button_press(GtkWidget* widget, GdkEventButton* event, gpointer data);
+
+// top event box
+gboolean top_event_box_button_press(GtkWidget* widget, GdkEventButton* event, gpointer data);
+
+// bottom event box
+gboolean bottom_event_box_button_press(GtkWidget* widget, GdkEventButton* event, gpointer data);
+