scroll up/down by tracks uses top edge as "focal point"; fix some other nasty code details

gtk2_ardour/editor.h

@@ -180,7 +180,6 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	void set_internal_edit (bool yn);
 	bool toggle_internal_editing_from_double_click (GdkEvent*);
 
-        void _ensure_time_axis_view_is_visible (TimeAxisView const & tav, bool at_top);
 	void foreach_time_axis_view (sigc::slot<void,TimeAxisView&>);
 	void add_to_idle_resize (TimeAxisView*, int32_t);
 
@@ -285,6 +284,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	framecnt_t         get_current_zoom () const { return samples_per_pixel; }
         void               cycle_zoom_focus ();
 	void temporal_zoom_step (bool coarser);
+        void ensure_time_axis_view_is_visible (TimeAxisView const & tav, bool at_top);
 	void tav_zoom_step (bool coarser);
 	void tav_zoom_smooth (bool coarser, bool force_all);
 

gtk2_ardour/editor_canvas.cc

@@ -805,7 +805,7 @@ Editor::entered_track_canvas (GdkEventCrossing */*ev*/)
 }
 
 void
-Editor::_ensure_time_axis_view_is_visible (TimeAxisView const & track, bool at_top)
+Editor::ensure_time_axis_view_is_visible (TimeAxisView const & track, bool at_top)
 {
 	if (track.hidden()) {
 		return;
@@ -822,19 +822,28 @@ Editor::_ensure_time_axis_view_is_visible (TimeAxisView const & track, bool at_t
 	double const track_max_y = track.y_position () + track.effective_height ();
 
 	if (!at_top && 
-	    (track_min_y > current_view_min_y &&
-	     track_max_y <= current_view_max_y)) {
+	    (track_min_y >= current_view_min_y &&
+	     track_max_y < current_view_max_y)) {
+		/* already visible, and caller did not ask to place it at the
+		 * top of the track canvas
+		 */
 		return;
 	}
 
 	double new_value;
 
-	if (track_min_y < current_view_min_y) {
-		// Track is above the current view
+	if (at_top) {
 		new_value = track_min_y;
 	} else {
-		// Track is below the current view
-		new_value = track.y_position () + track.effective_height() - vertical_adjustment.get_page_size();
+		if (track_min_y < current_view_min_y) {
+			// Track is above the current view
+			new_value = track_min_y;
+		} else if (track_max_y > current_view_max_y) {
+			// Track is below the current view
+			new_value = track.y_position () + track.effective_height() - vertical_adjustment.get_page_size();
+		} else {
+			new_value = track_min_y;
+		}
 	}
 
 	vertical_adjustment.set_value(new_value);

gtk2_ardour/editor_ops.cc

@@ -1364,32 +1364,35 @@ Editor::scroll_tracks_up_line ()
 bool
 Editor::scroll_down_one_track ()
 {
-	TrackViewList::reverse_iterator next = track_views.rend();
+	TrackViewList::reverse_iterator next = track_views.rbegin();
 	std::pair<TimeAxisView*,double> res;
-	const double bottom_of_trackviews = vertical_adjustment.get_value() + vertical_adjustment.get_page_size() - 1;
+	const double top_of_trackviews = vertical_adjustment.get_value();
 
 	for (TrackViewList::reverse_iterator t = track_views.rbegin(); t != track_views.rend(); ++t) {
 		if ((*t)->hidden()) {
 			continue;
 		}
-		
-		/* If this is the bottom visible trackview, we want to display
-		   the next one.
+
+		next = t;
+		if (next != track_views.rbegin()) {
+			--next; // moves "next" towards the lower/later tracks since it is a reverse iterator
+		}
+
+		/* If this is the upper-most visible trackview, we want to display
+		   the one above it (next)
 		*/
 
-		res = (*t)->covers_y_position (bottom_of_trackviews);
+		res = (*t)->covers_y_position (top_of_trackviews);
 
 		if (res.first) {
 			break;
 		}
-
-		++next; // moves "next" towards the "front" since it is a reverse iterator
 	}
 
 	/* move to the track below the first one that covers the */
 	
-	if (next != track_views.rend()) {
-		ensure_time_axis_view_is_visible (**next);
+	if (next != track_views.rbegin()) {
+		ensure_time_axis_view_is_visible (**next, true);
 		return true;
 	}
 
@@ -1399,11 +1402,10 @@ Editor::scroll_down_one_track ()
 bool
 Editor::scroll_up_one_track ()
 {
-	double vertical_pos = vertical_adjustment.get_value ();
-
 	TrackViewList::iterator prev = track_views.end();
 	std::pair<TimeAxisView*,double> res;
-
+	double top_of_trackviews = vertical_adjustment.get_value ();
+	
 	for (TrackViewList::iterator t = track_views.begin(); t != track_views.end(); ++t) {
 
 		if ((*t)->hidden()) {
@@ -1411,10 +1413,9 @@ Editor::scroll_up_one_track ()
 		}
 
 		/* find the trackview at the top of the trackview group */
-		res = (*t)->covers_y_position (vertical_pos);
+		res = (*t)->covers_y_position (top_of_trackviews);
 		
 		if (res.first) {
-			cerr << res.first->name() << " covers the top\n";
 			break;
 		}
 
@@ -1422,7 +1423,7 @@ Editor::scroll_up_one_track ()
 	}
 	
 	if (prev != track_views.end()) {
-		ensure_time_axis_view_is_visible (**prev);
+		ensure_time_axis_view_is_visible (**prev, true);
 		return true;
 	}
 
@@ -5637,7 +5638,7 @@ Editor::select_next_route()
 
 	selection->set(current);
 
-	ensure_time_axis_view_is_visible (*current);
+	ensure_time_axis_view_is_visible (*current, false);
 }
 
 void
@@ -5668,7 +5669,7 @@ Editor::select_prev_route()
 
 	selection->set (current);
 
-	ensure_time_axis_view_is_visible (*current);
+	ensure_time_axis_view_is_visible (*current, false);
 }
 
 void

gtk2_ardour/public_editor.h

@@ -276,11 +276,7 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible, publi
 	virtual framecnt_t current_page_samples() const = 0;
 	virtual double visible_canvas_height () const = 0;
 	virtual void temporal_zoom_step (bool coarser) = 0;
-	/* The virtual version, without a default argument, is protected below.
-	 */
-        void ensure_time_axis_view_is_visible (TimeAxisView const & tav, bool at_top = false) { 
-		_ensure_time_axis_view_is_visible (tav, at_top);
-	}
+        virtual void ensure_time_axis_view_is_visible (TimeAxisView const & tav, bool at_top = false) = 0;
         virtual void override_visible_track_count () = 0;
 	virtual void scroll_tracks_down_line () = 0;
 	virtual void scroll_tracks_up_line () = 0;
@@ -429,13 +425,6 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible, publi
 	PBD::Signal0<void> MouseModeChanged;
 
   protected:
-	/* This _ variant of ensure_time_axis_view_is_visible exists because
-	   C++ doesn't really like default values for virtual methods. So the
-	   public version is non-virtual, with a default value; the virtual
-	   (and protected) method here does not have a default value.
-	*/
-       virtual void _ensure_time_axis_view_is_visible (TimeAxisView const & tav, bool at_top) = 0;
-
 	friend class DisplaySuspender;
 	virtual void suspend_route_redisplay () = 0;
 	virtual void resume_route_redisplay () = 0;

gtk2_ardour/time_axis_view.cc

@@ -675,7 +675,7 @@ TimeAxisView::end_name_edit (int response)
 		}
 
 		if ((i != allviews.end()) && (*i != this) && !(*i)->hidden()) {
-			_editor.ensure_time_axis_view_is_visible (**i);
+			_editor.ensure_time_axis_view_is_visible (**i, false);
 			(*i)->begin_name_edit ();
 		} 
 
@@ -706,7 +706,7 @@ TimeAxisView::end_name_edit (int response)
 		}
 		
 		if ((i != allviews.end()) && (*i != this) && !(*i)->hidden()) {
-			_editor.ensure_time_axis_view_is_visible (**i);
+			_editor.ensure_time_axis_view_is_visible (**i, false);
 			(*i)->begin_name_edit ();
 		} 
 	}