Working with files, containing Curves

Curves, when opened, are represented in a way same with sections (see for details). So, the possibilities to work with and to represent the curves are the same with these possibilities for sections. When user opens curves in formats, that allow multiple curves to be in one file, like FemtoScan, Nanoscope III, NT-MDT, there can be several curves represented in the same window. In this situation one curve will be active and represented with solid line. The others will be represented with dashed lines. The Fourier spectrum will be shown for active curve only. User can choose active curve by pressing Tab button.