+ , canvas_group(new ArdourCanvas::Group(*_trackview.canvas_display))
+ , canvas_rect(new ArdourCanvas::SimpleRect (*canvas_group))
+ , _samples_per_unit(_trackview.editor.get_current_zoom())
+ , rec_updating(false)
+ , rec_active(false)
+ , use_rec_regions(tv.editor.show_waveforms_recording())
+ , region_color(_trackview.color())
+ , stream_base_color(0xFFFFFFFF)
+ , last_rec_data_frame(0)