track_sizer->Add (_track, 0, wxEXPAND | wxLEFT, DCPOMATIC_SIZER_X_GAP);
sizer->Add (track_sizer, 0, wxALL, DCPOMATIC_SIZER_GAP);
track_sizer->Add (_track, 0, wxEXPAND | wxLEFT, DCPOMATIC_SIZER_X_GAP);
sizer->Add (track_sizer, 0, wxALL, DCPOMATIC_SIZER_GAP);