different approach to independent scrolling, involving ArdourCanvas::ScrollGroup

The idea now is that a scroll group item can be added to the canvas which will causes its children to scroll in either or both
directions (horizontal or vertical). There are few complications: the position() of the ScrollGroup is ambiguous depending
on whether you want it with scroll taken into account or not, so Item::canvas_position() was added, which defaults to
the same value as Item::position() but is overridden by ScrollGroup to return the position independent of scrolling. This
method is used when translating between item/canvas/window coordinate systems.

Note that the basic idea is that we MOVE the scroll group when a scroll happens. This mirrors what happens in the GnomeCanvas,
where Nick Mainsbridge came up with a great idea that allowed unification of the time bar and track canvases.

1 files changed, 1 insertions, 1 deletions

diff --git a/libs/canvas/canvas/wave_view.h b/libs/canvas/canvas/wave_view.h
index 307528c685..0ddffca180 100644
--- a/libs/canvas/canvas/wave_view.h
+++ b/libs/canvas/canvas/wave_view.h
@@ -173,7 +173,7 @@ private:
         void handle_clip_level_change ();
 
         void ensure_cache (ARDOUR::framepos_t sample_start, ARDOUR::framepos_t sample_end) const;
-        ArdourCanvas::Coord position (double) const;
+        ArdourCanvas::Coord y_extent (double) const;
         void draw_image (ARDOUR::PeakData*, int npeaks) const;
 };