replace "-inf" with UTF8 infinity symbol
[ardour.git] / gtk2_ardour / automation_line.cc
index 5654ac22967dc31a0d8fec46d546a5e4156ab516..92ea8cf952850b6f2a72190ba2f10bd46a038468 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2002-2003 Paul Davis 
+    Copyright (C) 2002-2003 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
 #include <vector>
 #include <fstream>
 
-#include "pbd/stl_delete.h"
+#include "boost/shared_ptr.hpp"
+
+#include "pbd/floating.h"
 #include "pbd/memento_command.h"
+#include "pbd/stl_delete.h"
 #include "pbd/stacktrace.h"
 
 #include "ardour/automation_list.h"
 #include "ardour/dB.h"
+#include "ardour/debug.h"
+
 #include "evoral/Curve.hpp"
 
 #include "simplerect.h"
 #include "automation_line.h"
 #include "control_point.h"
+#include "gui_thread.h"
 #include "rgb_macros.h"
 #include "ardour_ui.h"
 #include "public_editor.h"
@@ -40,9 +46,7 @@
 #include "selection.h"
 #include "time_axis_view.h"
 #include "point_selection.h"
-#include "automation_selectable.h"
 #include "automation_time_axis.h"
-#include "public_editor.h"
 
 #include "ardour/event_type_map.h"
 #include "ardour/session.h"
 #include "i18n.h"
 
 using namespace std;
-using namespace sigc;
 using namespace ARDOUR;
 using namespace PBD;
 using namespace Editing;
 using namespace Gnome; // for Canvas
 
-static const Evoral::IdentityConverter<double, sframes_t> default_converter;
-
+/** @param converter A TimeConverter whose origin_b is the start time of the AutomationList in session frames.
+ *  This will not be deleted by AutomationLine.
+ */
 AutomationLine::AutomationLine (const string& name, TimeAxisView& tv, ArdourCanvas::Group& parent,
                boost::shared_ptr<AutomationList> al,
-               const Evoral::TimeConverter<double, sframes_t>* converter)
+               Evoral::TimeConverter<double, framepos_t>* converter)
        : trackview (tv)
        , _name (name)
        , alist (al)
+       , _time_converter (converter ? converter : new Evoral::IdentityConverter<double, framepos_t>)
        , _parent_group (parent)
-       , _time_converter (converter ? (*converter) : default_converter)
+       , _offset (0)
+       , _maximum_time (max_framepos)
 {
-       _interpolation = al->interpolation();
-       points_visible = false;
+       if (converter) {
+               _time_converter = converter;
+               _our_time_converter = false;
+       } else {
+               _time_converter = new Evoral::IdentityConverter<double, framepos_t>;
+               _our_time_converter = true;
+       }
+       
+       _visible = Line;
+
        update_pending = false;
+       have_timeout = false;
        _uses_gain_mapping = false;
        no_draw = false;
-       _visible = true;
+       _is_boolean = false;
        terminal_points_can_slide = true;
        _height = 0;
 
@@ -84,24 +99,28 @@ AutomationLine::AutomationLine (const string& name, TimeAxisView& tv, ArdourCanv
        line->property_width_pixels() = (guint)1;
        line->set_data ("line", this);
 
-       line->signal_event().connect (mem_fun (*this, &AutomationLine::event_handler));
-
-       alist->StateChanged.connect (mem_fun(*this, &AutomationLine::list_changed));
+       line->signal_event().connect (sigc::mem_fun (*this, &AutomationLine::event_handler));
 
-       trackview.session().register_with_memento_command_factory(alist->id(), this);
+       trackview.session()->register_with_memento_command_factory(alist->id(), this);
 
        if (alist->parameter().type() == GainAutomation ||
            alist->parameter().type() == EnvelopeAutomation) {
                set_uses_gain_mapping (true);
        }
 
-       set_interpolation(alist->interpolation());
+       interpolation_changed (alist->interpolation ());
+
+       connect_to_list ();
 }
 
 AutomationLine::~AutomationLine ()
 {
        vector_delete (&control_points);
        delete group;
+
+       if (_our_time_converter) {
+               delete _time_converter;
+       }
 }
 
 bool
@@ -111,53 +130,57 @@ AutomationLine::event_handler (GdkEvent* event)
 }
 
 void
-AutomationLine::queue_reset ()
-{
-       if (!update_pending) {
-               update_pending = true;
-               Gtkmm2ext::UI::instance()->call_slot (mem_fun(*this, &AutomationLine::reset));
-       }
-}
-
-void
-AutomationLine::show () 
+AutomationLine::show ()
 {
-       if (_interpolation != AutomationList::Discrete) {
-               line->show();
+       if (_visible & Line) {
+               /* Only show the line there are some points, otherwise we may show an out-of-date line
+                  when automation points have been removed (the line will still follow the shape of the
+                  old points).
+               */
+               if (alist->interpolation() != AutomationList::Discrete && control_points.size() >= 2) {
+                       line->show();
+               } else {
+                       line->hide ();
+               }
+       } else {
+               line->hide();
        }
 
-       if (points_visible) {
+       if (_visible & ControlPoints) {
                for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+                       (*i)->set_visible (true);
                        (*i)->show ();
                }
+       } else if (_visible & SelectedControlPoints) {
+               for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+                       (*i)->set_visible ((*i)->get_selected());
+               }
+       } else {
+               for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+                       (*i)->set_visible (false);
+               }
        }
-
-       _visible = true;
 }
 
 void
-AutomationLine::hide () 
+AutomationLine::hide ()
 {
-       line->hide();
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               (*i)->hide();
-       }
-       _visible = false;
+       set_visibility (VisibleAspects (0));
 }
 
 double
 AutomationLine::control_point_box_size ()
 {
-       if (_interpolation == AutomationList::Discrete) {
+       if (alist->interpolation() == AutomationList::Discrete) {
                return max((_height*4.0) / (double)(alist->parameter().max() - alist->parameter().min()),
                                4.0);
        }
 
-       if (_height > TimeAxisView::hLarger) {
+       if (_height > TimeAxisView::preset_height (HeightLarger)) {
                return 8.0;
-       } else if (_height > (guint32) TimeAxisView::hNormal) {
+       } else if (_height > (guint32) TimeAxisView::preset_height (HeightNormal)) {
                return 6.0;
-       } 
+       }
        return 4.0;
 }
 
@@ -203,6 +226,16 @@ AutomationLine::nth (uint32_t n)
        }
 }
 
+ControlPoint const *
+AutomationLine::nth (uint32_t n) const
+{
+       if (n < control_points.size()) {
+               return control_points[n];
+       } else {
+               return 0;
+       }
+}
+
 void
 AutomationLine::modify_point_y (ControlPoint& cp, double y)
 {
@@ -214,12 +247,15 @@ AutomationLine::modify_point_y (ControlPoint& cp, double y)
        y = min (1.0, y);
        y = _height - (y * _height);
 
-       double const x = trackview.editor().frame_to_unit (_time_converter.to((*cp.model())->when));
+       double const x = trackview.editor().frame_to_unit_unrounded (_time_converter->to((*cp.model())->when) - _offset);
 
-       trackview.editor().current_session()->begin_reversible_command (_("automation event move"));
-       trackview.editor().current_session()->add_command (new MementoCommand<AutomationList>(*alist.get(), &get_state(), 0));
+       trackview.editor().session()->begin_reversible_command (_("automation event move"));
+       trackview.editor().session()->add_command (
+               new MementoCommand<AutomationList> (memento_command_binder(), &get_state(), 0)
+               );
 
        cp.move_to (x, y, ControlPoint::Full);
+
        reset_line_coords (cp);
 
        if (line_points.size() > 1) {
@@ -227,702 +263,517 @@ AutomationLine::modify_point_y (ControlPoint& cp, double y)
        }
 
        alist->freeze ();
-       sync_model_with_view_point (cp, false, 0);
+       sync_model_with_view_point (cp);
        alist->thaw ();
 
        update_pending = false;
 
-       trackview.editor().current_session()->add_command (new MementoCommand<AutomationList>(*alist.get(), 0, &alist->get_state()));
-       trackview.editor().current_session()->commit_reversible_command ();
-       trackview.editor().current_session()->set_dirty ();
+       trackview.editor().session()->add_command (
+               new MementoCommand<AutomationList> (memento_command_binder(), 0, &alist->get_state())
+               );
+
+       trackview.editor().session()->commit_reversible_command ();
+       trackview.editor().session()->set_dirty ();
 }
 
+void
+AutomationLine::reset_line_coords (ControlPoint& cp)
+{
+       if (cp.view_index() < line_points.size()) {
+               line_points[cp.view_index()].set_x (cp.get_x());
+               line_points[cp.view_index()].set_y (cp.get_y());
+       }
+}
 
 void
-AutomationLine::modify_view_point (ControlPoint& cp, double x, double y, bool with_push)
+AutomationLine::sync_model_with_view_points (list<ControlPoint*> cp)
 {
-       double delta = 0.0;
-       uint32_t last_movable = UINT_MAX;
-       double x_limit = DBL_MAX;
+       update_pending = true;
 
-       /* this just changes the current view. it does not alter
-          the model in any way at all.
-       */
+       for (list<ControlPoint*>::iterator i = cp.begin(); i != cp.end(); ++i) {
+               sync_model_with_view_point (**i);
+       }
+}
 
-       /* clamp y-coord appropriately. y is supposed to be a normalized fraction (0.0-1.0),
-          and needs to be converted to a canvas unit distance.
-       */
+string
+AutomationLine::get_verbose_cursor_string (double fraction) const
+{
+       std::string s = fraction_to_string (fraction);
+       if (_uses_gain_mapping) {
+               s += " dB";
+       }
 
-       y = max (0.0, y);
-       y = min (1.0, y);
-       y = _height - (y * _height);
+       return s;
+}
 
-       if (cp.can_slide()) {
+string
+AutomationLine::get_verbose_cursor_relative_string (double original, double fraction) const
+{
+       std::string s = fraction_to_string (fraction);
+       if (_uses_gain_mapping) {
+               s += " dB";
+       }
 
-               /* x-coord cannot move beyond adjacent points or the start/end, and is
-                  already in frames. it needs to be converted to canvas units.
-               */
-               
-               x = trackview.editor().frame_to_unit (x);
+       std::string d = fraction_to_relative_string (original, fraction);
 
-               /* clamp x position using view coordinates */
+       if (!d.empty()) {
 
-               ControlPoint *before;
-               ControlPoint *after;
+               s += " (\u0394";
+               s += d;
 
-               if (cp.view_index()) {
-                       before = nth (cp.view_index() - 1);
-                       x = max (x, before->get_x()+1.0);
-               } else {
-                       before = &cp;
+               if (_uses_gain_mapping) {
+                       s += " dB";
                }
 
+               s += ')';
+       }
 
-               if (!with_push) {
-                       if (cp.view_index() < control_points.size() - 1) {
-               
-                               after = nth (cp.view_index() + 1);
-               
-                               /*if it is a "spike" leave the x alone */
-                               if (after->get_x() - before->get_x() < 2) {
-                                       x = cp.get_x();
-                                       
-                               } else {
-                                       x = min (x, after->get_x()-1.0);
-                               }
-                       } else {
-                               after = &cp;
-                       }
+       return s;
+}
 
-               } else {
+/**
+ *  @param fraction y fraction
+ *  @return string representation of this value, using dB if appropriate.
+ */
+string
+AutomationLine::fraction_to_string (double fraction) const
+{
+       char buf[32];
 
-                       ControlPoint* after;
-                       
-                       /* find the first point that can't move */
-
-                       for (uint32_t n = cp.view_index() + 1; (after = nth (n)) != 0; ++n) {
-                               if (!after->can_slide()) {
-                                       x_limit = after->get_x() - 1.0;
-                                       last_movable = after->view_index();
-                                       break;
-                               }
-                       }
-                       
-                       delta = x - cp.get_x();
+       if (_uses_gain_mapping) {
+               if (fraction == 0.0) {
+                       snprintf (buf, sizeof (buf), "-\u221e");
+               } else {
+                       snprintf (buf, sizeof (buf), "%.1f", accurate_coefficient_to_dB (slider_position_to_gain_with_max (fraction, Config->get_max_gain())));
                }
-                       
        } else {
+               view_to_model_coord_y (fraction);
+               if (EventTypeMap::instance().is_integer (alist->parameter())) {
+                       snprintf (buf, sizeof (buf), "%d", (int)fraction);
+               } else {
+                       snprintf (buf, sizeof (buf), "%.2f", fraction);
+               }
+       }
 
-               /* leave the x-coordinate alone */
+       return buf;
+}
+
+/**
+ *  @param original an old y-axis fraction
+ *  @param fraction the new y fraction
+ *  @return string representation of the difference between original and fraction, using dB if appropriate.
+ */
+string
+AutomationLine::fraction_to_relative_string (double original, double fraction) const
+{
+       char buf[32];
 
-               x = trackview.editor().frame_to_unit (_time_converter.to((*cp.model())->when));
+       if (original == fraction) {
+               return "0";
+       }
 
+       if (_uses_gain_mapping) {
+               if (original == 0.0) {
+                       /* there is no sensible representation of a relative
+                          change from -inf dB, so return an empty string.
+                       */
+                       return "";
+               } else if (fraction == 0.0) {
+                       snprintf (buf, sizeof (buf), "-\u221e");
+               } else {
+                       double old_db = accurate_coefficient_to_dB (slider_position_to_gain_with_max (original, Config->get_max_gain()));
+                       double new_db = accurate_coefficient_to_dB (slider_position_to_gain_with_max (fraction, Config->get_max_gain()));
+                       snprintf (buf, sizeof (buf), "%.1f", new_db - old_db);
+               }
+       } else {
+               view_to_model_coord_y (original);
+               view_to_model_coord_y (fraction);
+               if (EventTypeMap::instance().is_integer (alist->parameter())) {
+                       snprintf (buf, sizeof (buf), "%d", (int)fraction - (int)original);
+               } else {
+                       snprintf (buf, sizeof (buf), "%.2f", fraction - original);
+               }
        }
 
-       if (!with_push) {
+       return buf;
+}
+
+/**
+ *  @param s Value string in the form as returned by fraction_to_string.
+ *  @return Corresponding y fraction.
+ */
+double
+AutomationLine::string_to_fraction (string const & s) const
+{
+       if (s == "-\u221e") {
+               return 0;
+       }
 
-               cp.move_to (x, y, ControlPoint::Full);
-               reset_line_coords (cp);
+       double v;
+       sscanf (s.c_str(), "%lf", &v);
 
+       if (_uses_gain_mapping) {
+               v = gain_to_slider_position_with_max (dB_to_coefficient (v), Config->get_max_gain());
        } else {
+               double dummy = 0.0;
+               model_to_view_coord (dummy, v);
+       }
 
-               uint32_t limit = min (control_points.size(), (size_t)last_movable);
-               
-               /* move the current point to wherever the user told it to go, subject
-                  to x_limit.
-               */
-               
-               cp.move_to (min (x, x_limit), y, ControlPoint::Full);
-               reset_line_coords (cp);
-               
-               /* now move all subsequent control points, to reflect the motion.
-                */
-               
-               for (uint32_t i = cp.view_index() + 1; i < limit; ++i) {
-                       ControlPoint *p = nth (i);
-                       double new_x;
+       return v;
+}
 
-                       if (p->can_slide()) {
-                               new_x = min (p->get_x() + delta, x_limit);
-                               p->move_to (new_x, p->get_y(), ControlPoint::Full);
-                               reset_line_coords (*p);
+/** Start dragging a single point, possibly adding others if the supplied point is selected and there
+ *  are other selected points.
+ *
+ *  @param cp Point to drag.
+ *  @param x Initial x position (units).
+ *  @param fraction Initial y position (as a fraction of the track height, where 0 is the bottom and 1 the top)
+ */
+void
+AutomationLine::start_drag_single (ControlPoint* cp, double x, float fraction)
+{
+       trackview.editor().session()->begin_reversible_command (_("automation event move"));
+       trackview.editor().session()->add_command (
+               new MementoCommand<AutomationList> (memento_command_binder(), &get_state(), 0)
+               );
+
+       _drag_points.clear ();
+       _drag_points.push_back (cp);
+
+       if (cp->get_selected ()) {
+               for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+                       if (*i != cp && (*i)->get_selected()) {
+                               _drag_points.push_back (*i);
                        }
                }
        }
-}
 
-void
-AutomationLine::reset_line_coords (ControlPoint& cp)
-{      
-       if (cp.view_index() < line_points.size()) {
-               line_points[cp.view_index()].set_x (cp.get_x());
-               line_points[cp.view_index()].set_y (cp.get_y());
-       }
+       start_drag_common (x, fraction);
 }
 
+/** Start dragging a line vertically (with no change in x)
+ *  @param i1 Control point index of the `left' point on the line.
+ *  @param i2 Control point index of the `right' point on the line.
+ *  @param fraction Initial y position (as a fraction of the track height, where 0 is the bottom and 1 the top)
+ */
 void
-AutomationLine::sync_model_with_view_line (uint32_t start, uint32_t end)
+AutomationLine::start_drag_line (uint32_t i1, uint32_t i2, float fraction)
 {
-       ControlPoint *p;
+       trackview.editor().session()->begin_reversible_command (_("automation range move"));
+       trackview.editor().session()->add_command (
+               new MementoCommand<AutomationList> (memento_command_binder (), &get_state(), 0)
+               );
 
-       update_pending = true;
+       _drag_points.clear ();
 
-       for (uint32_t i = start; i <= end; ++i) {
-               p = nth(i);
-               sync_model_with_view_point (*p, false, 0);
+       for (uint32_t i = i1; i <= i2; i++) {
+               _drag_points.push_back (nth (i));
        }
+
+       start_drag_common (0, fraction);
 }
 
+/** Start dragging multiple points (with no change in x)
+ *  @param cp Points to drag.
+ *  @param fraction Initial y position (as a fraction of the track height, where 0 is the bottom and 1 the top)
+ */
 void
-AutomationLine::model_representation (ControlPoint& cp, ModelRepresentation& mr)
+AutomationLine::start_drag_multiple (list<ControlPoint*> cp, float fraction, XMLNode* state)
 {
-       /* part one: find out where the visual control point is.
-          initial results are in canvas units. ask the
-          line to convert them to something relevant.
-       */
-       
-       mr.xval = cp.get_x();
-       mr.yval = 1.0 - (cp.get_y() / _height);
+       trackview.editor().session()->begin_reversible_command (_("automation range move"));
+       trackview.editor().session()->add_command (
+               new MementoCommand<AutomationList> (memento_command_binder(), state, 0)
+               );
 
-       /* if xval has not changed, set it directly from the model to avoid rounding errors */
+       _drag_points = cp;
+       start_drag_common (0, fraction);
+}
 
-       if (mr.xval == trackview.editor().frame_to_unit(_time_converter.to((*cp.model())->when))) {
-               mr.xval = (*cp.model())->when;
-       } else {
-               mr.xval = trackview.editor().unit_to_frame (mr.xval);
+struct ControlPointSorter
+{
+       bool operator() (ControlPoint const * a, ControlPoint const * b) const {
+               if (floateq (a->get_x(), b->get_x(), 1)) {
+                       return a->view_index() < b->view_index();
+               } 
+               return a->get_x() < b->get_x();
        }
+};
 
-       /* convert to model units
-       */
-       
-       view_to_model_coord (mr.xval, mr.yval);
+AutomationLine::ContiguousControlPoints::ContiguousControlPoints (AutomationLine& al)
+       : line (al), before_x (0), after_x (DBL_MAX) 
+{
+}
 
-       /* part 2: find out where the model point is now
-        */
+void
+AutomationLine::ContiguousControlPoints::compute_x_bounds ()
+{
+       uint32_t sz = size();
 
-       mr.xpos = (*cp.model())->when;
-       mr.ypos = (*cp.model())->value;
+       if (sz > 0 && sz < line.npoints()) {
 
-       /* part 3: get the position of the visual control
-          points before and after us.
-       */
+               /* determine the limits on x-axis motion for this 
+                  contiguous range of control points
+               */
+
+               if (front()->view_index() > 0) {
+                       before_x = line.nth (front()->view_index() - 1)->get_x();
+               }
 
-       ControlPoint* before;
-       ControlPoint* after;
+               /* if our last point has a point after it in the line,
+                  we have an "after" bound
+               */
 
-       if (cp.view_index()) {
-               before = nth (cp.view_index() - 1);
-       } else {
-               before = 0;
+               if (back()->view_index() < (line.npoints() - 2)) {
+                       after_x = line.nth (back()->view_index() + 1)->get_x();
+               }
        }
+}
 
-       after = nth (cp.view_index() + 1);
+double 
+AutomationLine::ContiguousControlPoints::clamp_dx (double dx) 
+{
+       if (empty()) {
+               return dx;
+       }
 
-       if (before) {
-               mr.xmin = (*before->model())->when;
-               mr.ymin = (*before->model())->value;
-               mr.start = before->model();
-               ++mr.start;
+       /* get the maximum distance we can move any of these points along the x-axis
+        */
+       
+       double tx; /* possible position a point would move to, given dx */
+       ControlPoint* cp;
+       
+       if (dx > 0) {
+               /* check the last point, since we're moving later in time */
+               cp = back();
        } else {
-               mr.xmin = mr.xpos;
-               mr.ymin = mr.ypos;
-               mr.start = cp.model();
+               /* check the first point, since we're moving earlier in time */
+               cp = front();
        }
 
-       if (after) {
-               mr.end = after->model();
-       } else {
-               mr.xmax = mr.xpos;
-               mr.ymax = mr.ypos;
-               mr.end = cp.model();
-               ++mr.end;
+       tx = cp->get_x() + dx; // new possible position if we just add the motion 
+       tx = max (tx, before_x); // can't move later than following point
+       tx = min (tx, after_x);  // can't move earlier than preceeding point
+       return  tx - cp->get_x (); 
+}
+
+void 
+AutomationLine::ContiguousControlPoints::move (double dx, double dy) 
+{
+       for (std::list<ControlPoint*>::iterator i = begin(); i != end(); ++i) {
+               (*i)->move_to ((*i)->get_x() + dx, (*i)->get_y() - line.height() * dy, ControlPoint::Full);
+               line.reset_line_coords (**i);
        }
 }
 
+/** Common parts of starting a drag.
+ *  @param x Starting x position in units, or 0 if x is being ignored.
+ *  @param fraction Starting y position (as a fraction of the track height, where 0 is the bottom and 1 the top)
+ */
 void
-AutomationLine::determine_visible_control_points (ALPoints& points)
-{
-       uint32_t view_index, pi, n;
-       AutomationList::iterator model;
-       uint32_t npoints;
-       double last_control_point_x = 0.0;
-       double last_control_point_y = 0.0;
-       uint32_t this_rx = 0;
-       uint32_t prev_rx = 0;
-       uint32_t this_ry = 0;
-       uint32_t prev_ry = 0;   
-       double* slope;
-       uint32_t box_size;
-       uint32_t cpsize;
+AutomationLine::start_drag_common (double x, float fraction)
+{
+       _drag_x = x;
+       _drag_distance = 0;
+       _last_drag_fraction = fraction;
+       _drag_had_movement = false;
+       did_push = false;
 
-       /* hide all existing points, and the line */
+       /* they are probably ordered already, but we have to make sure */
 
-       cpsize = 0;
-       
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               (*i)->hide();
-               ++cpsize;
-       }
+       _drag_points.sort (ControlPointSorter());
+}
 
-       line->hide ();
 
-       if (points.empty()) {
-               return;
+/** Should be called to indicate motion during a drag.
+ *  @param x New x position of the drag in canvas units, or undefined if ignore_x == true.
+ *  @param fraction New y fraction.
+ *  @return x position and y fraction that were actually used (once clamped).
+ */
+pair<double, float>
+AutomationLine::drag_motion (double const x, float fraction, bool ignore_x, bool with_push, uint32_t& final_index)
+{
+       if (_drag_points.empty()) {
+               return pair<double,float> (x,fraction);
        }
 
-       npoints = points.size();
+       double dx = ignore_x ? 0 : (x - _drag_x);
+       double dy = fraction - _last_drag_fraction;
 
-       /* compute derivative/slope for the entire line */
+       if (!_drag_had_movement) {
 
-       slope = new double[npoints];
+               /* "first move" ... do some stuff that we don't want to do if 
+                  no motion ever took place, but need to do before we handle
+                  motion.
+               */
+       
+               /* partition the points we are dragging into (potentially several)
+                * set(s) of contiguous points. this will not happen with a normal
+                * drag, but if the user does a discontiguous selection, it can.
+                */
+               
+               uint32_t expected_view_index = 0;
+               CCP contig;
+               
+               for (list<ControlPoint*>::iterator i = _drag_points.begin(); i != _drag_points.end(); ++i) {
+                       if (i == _drag_points.begin() || (*i)->view_index() != expected_view_index) {
+                               contig.reset (new ContiguousControlPoints (*this));
+                               contiguous_points.push_back (contig);
+                       }
+                       contig->push_back (*i);
+                       expected_view_index = (*i)->view_index() + 1;
+               }
 
-       for (n = 0; n < npoints - 1; ++n) {
-               double xdelta = points[n+1].x - points[n].x;
-               double ydelta = points[n+1].y - points[n].y;
-               slope[n] = ydelta/xdelta;
-       }
+               if (contiguous_points.back()->empty()) {
+                       contiguous_points.pop_back ();
+               }
 
-       box_size = (uint32_t) control_point_box_size ();
+               for (vector<CCP>::iterator ccp = contiguous_points.begin(); ccp != contiguous_points.end(); ++ccp) {
+                       (*ccp)->compute_x_bounds ();
+               }
+       }       
+
+       /* OK, now on to the stuff related to *this* motion event. First, for
+        * each contiguous range, figure out the maximum x-axis motion we are
+        * allowed (because of neighbouring points that are not moving.
+        * 
+        * if we are moving forwards with push, we don't need to do this, 
+        * since all later points will move too.
+        */
 
-       /* read all points and decide which ones to show as control points */
+       if (dx < 0 || ((dx > 0) && !with_push)) {
+               for (vector<CCP>::iterator ccp = contiguous_points.begin(); ccp != contiguous_points.end(); ++ccp) {
+                       double dxt = (*ccp)->clamp_dx (dx);
+                       if (fabs (dxt) < fabs (dx)) {
+                               dx = dxt;
+                       }
+               }
+       }
 
-       view_index = 0;
+       /* clamp y */
+       
+       for (list<ControlPoint*>::iterator i = _drag_points.begin(); i != _drag_points.end(); ++i) {
+               double const y = ((_height - (*i)->get_y()) / _height) + dy;
+               if (y < 0) {
+                       dy -= y;
+               }
+               if (y > 1) {
+                       dy -= (y - 1);
+               }
+       }
 
-       for (model = alist->begin(), pi = 0; pi < npoints; ++model, ++pi) {
+       if (dx || dy) {
 
-               double tx = points[pi].x;
-               double ty = points[pi].y;
+               /* and now move each section */
                
-               if (isnan (tx) || isnan (ty)) {
-                       warning << string_compose (_("Ignoring illegal points on AutomationLine \"%1\""),
-                                                  _name) << endmsg;
-                       continue;
+               for (vector<CCP>::iterator ccp = contiguous_points.begin(); ccp != contiguous_points.end(); ++ccp) {
+                       (*ccp)->move (dx, dy);
+               }
+               if (with_push) {
+                       final_index = contiguous_points.back()->back()->view_index () + 1;
+                       ControlPoint* p;
+                       uint32_t i = final_index;
+                       while ((p = nth (i)) != 0 && p->can_slide()) {
+                               p->move_to (p->get_x() + dx, p->get_y(), ControlPoint::Full);
+                               reset_line_coords (*p);
+                               ++i;
+                       }
                }
 
-               /* now ensure that the control_points vector reflects the current curve
-                  state, but don't plot control points too close together. also, don't
-                  plot a series of points all with the same value.
-
-                  always plot the first and last points, of course.
-               */
+               /* update actual line coordinates (will queue a redraw)
+                */
 
-               if (invalid_point (points, pi)) {
-                       /* for some reason, we are supposed to ignore this point,
-                          but still keep track of the model index.
-                       */
-                       continue;
+               if (line_points.size() > 1) {
+                       line->property_points() = line_points;
                }
+       }
+       
+       _drag_distance += dx;
+       _drag_x += dx;
+       _last_drag_fraction = fraction;
+       _drag_had_movement = true;
+       did_push = with_push;
 
-               if (pi > 0 && pi < npoints - 1) {
-                       if (slope[pi] == slope[pi-1]) {
-
-                               /* no reason to display this point */
-                               
-                               continue;
-                       }
-               }
-               
-               /* need to round here. the ultimate coordinates are integer
-                  pixels, so tiny deltas in the coords will be eliminated
-                  and we end up with "colinear" line segments. since the
-                  line rendering code in libart doesn't like this very
-                  much, we eliminate them here. don't do this for the first and last
-                  points.
-               */
-
-               this_rx = (uint32_t) rint (tx);
-               this_ry = (uint32_t) rint (ty); 
-               if (view_index && pi != npoints && /* not the first, not the last */
-                   (((this_rx == prev_rx) && (this_ry == prev_ry)) || /* same point */
-                    (((this_rx - prev_rx) < (box_size + 2)) &&  /* not identical, but still too close horizontally */
-                     (abs ((int)(this_ry - prev_ry)) < (int) (box_size + 2))))) { /* too close vertically */
-                       continue;
-               } 
-
-               /* ok, we should display this point */
-
-               if (view_index >= cpsize) {
-
-                       /* make sure we have enough control points */
-
-                       ControlPoint* ncp = new ControlPoint (*this);
-                       
-                       ncp->set_size (box_size); 
-
-                       control_points.push_back (ncp);
-                       ++cpsize;
-               }
-
-               ControlPoint::ShapeType shape;
-
-               if (!terminal_points_can_slide) {
-                       if (pi == 0) {
-                               control_points[view_index]->set_can_slide(false);
-                               if (tx == 0) {
-                                       shape = ControlPoint::Start;
-                               } else {
-                                       shape = ControlPoint::Full;
-                               }
-                       } else if (pi == npoints - 1) {
-                               control_points[view_index]->set_can_slide(false);
-                               shape = ControlPoint::End;
-                       } else {
-                               control_points[view_index]->set_can_slide(true);
-                               shape = ControlPoint::Full;
-                       }
-               } else {
-                       control_points[view_index]->set_can_slide(true);
-                       shape = ControlPoint::Full;
-               }
-
-               last_control_point_x = tx;
-               last_control_point_y = ty;
-
-               control_points[view_index]->reset (tx, ty, model, view_index, shape);
-
-               prev_rx = this_rx;
-               prev_ry = this_ry;
-
-               /* finally, control visibility */
-               
-               if (_visible && points_visible) {
-                       control_points[view_index]->show ();
-                       control_points[view_index]->set_visible (true);
-               } else {
-                       if (!points_visible) {
-                               control_points[view_index]->set_visible (false);
-                       }
-               }
-
-               view_index++;
-       }
-       
-       /* discard extra CP's to avoid confusing ourselves */
-
-       while (control_points.size() > view_index) {
-               ControlPoint* cp = control_points.back();
-               control_points.pop_back ();
-               delete cp;
-       }
-
-       if (!terminal_points_can_slide) {
-               control_points.back()->set_can_slide(false);
-       }
-
-       delete [] slope;
-
-       if (view_index > 1) {
-
-               npoints = view_index;
-               
-               /* reset the line coordinates */
-
-               while (line_points.size() < npoints) {
-                       line_points.push_back (Art::Point (0,0));
-               }
-
-               while (line_points.size() > npoints) {
-                       line_points.pop_back ();
-               }
-
-               for (view_index = 0; view_index < npoints; ++view_index) {
-                       line_points[view_index].set_x (control_points[view_index]->get_x());
-                       line_points[view_index].set_y (control_points[view_index]->get_y());
-               }
-               
-               line->property_points() = line_points;
-
-               if (_visible && _interpolation != AutomationList::Discrete) {
-                       line->show();
-               }
-
-       } 
-
-       set_selected_points (trackview.editor().get_selection().points);
-
-}
-
-string
-AutomationLine::get_verbose_cursor_string (double fraction) const
-{
-       std::string s = fraction_to_string (fraction);
-       if (_uses_gain_mapping) {
-               s += " dB";
-       }
-
-       return s;
-}
-
-/**
- *  @param fraction y fraction
- *  @return string representation of this value, using dB if appropriate.
- */
-string
-AutomationLine::fraction_to_string (double fraction) const
-{
-       char buf[32];
-
-       if (_uses_gain_mapping) {
-               if (fraction == 0.0) {
-                       snprintf (buf, sizeof (buf), "-inf");
-               } else {
-                       snprintf (buf, sizeof (buf), "%.1f", coefficient_to_dB (slider_position_to_gain (fraction)));
-               }
-       } else {
-               double dummy = 0.0;
-               view_to_model_coord (dummy, fraction);
-               if (EventTypeMap::instance().is_integer (alist->parameter())) {
-                       snprintf (buf, sizeof (buf), "%d", (int)fraction);
-               } else {
-                       snprintf (buf, sizeof (buf), "%.2f", fraction);
-               }
-       }
-
-       return buf;
-}
-
-
-/**
- *  @param s Value string in the form as returned by fraction_to_string.
- *  @return Corresponding y fraction.
- */
-double
-AutomationLine::string_to_fraction (string const & s) const
-{
-       if (s == "-inf") {
-               return 0;
-       }
-
-       double v;
-       sscanf (s.c_str(), "%lf", &v);
-       
-       if (_uses_gain_mapping) {
-               v = gain_to_slider_position (dB_to_coefficient (v));
-       } else {
-               double dummy = 0.0;
-               model_to_view_coord (dummy, v);
-       }
-
-       return v;
-}
-
-bool
-AutomationLine::invalid_point (ALPoints& p, uint32_t index)
-{
-       return p[index].x == max_frames && p[index].y == DBL_MAX;
-}
-
-void
-AutomationLine::invalidate_point (ALPoints& p, uint32_t index)
-{
-       p[index].x = max_frames;
-       p[index].y = DBL_MAX;
-}
+       return pair<double, float> (_drag_x + dx, _last_drag_fraction + dy);
+}
 
+/** Should be called to indicate the end of a drag */
 void
-AutomationLine::start_drag (ControlPoint* cp, nframes_t x, float fraction) 
+AutomationLine::end_drag (bool with_push, uint32_t final_index)
 {
-       if (trackview.editor().current_session() == 0) { /* how? */
+       if (!_drag_had_movement) {
                return;
        }
 
-       string str;
-
-       if (cp) {
-               str = _("automation event move");
-       } else {
-               str = _("automation range drag");
-       }
-
-       trackview.editor().current_session()->begin_reversible_command (str);
-       trackview.editor().current_session()->add_command (new MementoCommand<AutomationList>(*alist.get(), &get_state(), 0));
-       
-       drag_x = x;
-       drag_distance = 0;
-       first_drag_fraction = fraction;
-       last_drag_fraction = fraction;
-       drags = 0;
-       did_push = false;
-}
-
-void
-AutomationLine::point_drag (ControlPoint& cp, nframes_t x, float fraction, bool with_push) 
-{
-       if (x > drag_x) {
-               drag_distance += (x - drag_x);
-       } else {
-               drag_distance -= (drag_x - x);
-       }
-
-       drag_x = x;
-
-       modify_view_point (cp, x, fraction, with_push);
-
-       if (line_points.size() > 1) {
-               line->property_points() = line_points;
-       }
-
-       drags++;
-       did_push = with_push;
-}
-
-void
-AutomationLine::line_drag (uint32_t i1, uint32_t i2, float fraction, bool with_push) 
-{
-       double ydelta = fraction - last_drag_fraction;
-
-       did_push = with_push;
-       
-       last_drag_fraction = fraction;
-
-       line_drag_cp1 = i1;
-       line_drag_cp2 = i2;
-       
-       //check if one of the control points on the line is in a selected range
-       bool range_found = false;
-       ControlPoint *cp;
-
-       for (uint32_t i = i1 ; i <= i2; i++) {
-               cp = nth (i);
-               if (cp->selected()) {
-                       range_found = true;
-               }
-       }
-
-       if (range_found) {
-               for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-                       if ((*i)->selected()) {
-                               modify_view_point (*(*i), trackview.editor().unit_to_frame ((*i)->get_x()), ((_height - (*i)->get_y()) /_height) + ydelta, with_push);
-                       }
-               }
-       } else {
-               ControlPoint *cp;
-               for (uint32_t i = i1 ; i <= i2; i++) {
-                       cp = nth (i);
-                       modify_view_point (*cp, trackview.editor().unit_to_frame (cp->get_x()), ((_height - cp->get_y()) /_height) + ydelta, with_push);
+       alist->freeze ();
+       sync_model_with_view_points (_drag_points);
+
+       if (with_push) {
+               ControlPoint* p;
+               uint32_t i = final_index;
+               while ((p = nth (i)) != 0 && p->can_slide()) {
+                       sync_model_with_view_point (*p);
+                       ++i;
                }
        }
-       
-       if (line_points.size() > 1) {
-               line->property_points() = line_points;
-       }
-
-       drags++;
-}
-
-void
-AutomationLine::end_drag (ControlPoint* cp) 
-{
-       if (!drags) {
-               return;
-       }
 
-       alist->freeze ();
-
-       if (cp) {
-               sync_model_with_view_point (*cp, did_push, drag_distance);
-       } else {
-               sync_model_with_view_line (line_drag_cp1, line_drag_cp2);
-       }
-       
        alist->thaw ();
 
        update_pending = false;
 
-       trackview.editor().current_session()->add_command (new MementoCommand<AutomationList>(*alist.get(), 0, &alist->get_state()));
-       trackview.editor().current_session()->commit_reversible_command ();
-       trackview.editor().current_session()->set_dirty ();
-}
+       trackview.editor().session()->add_command (
+               new MementoCommand<AutomationList>(memento_command_binder (), 0, &alist->get_state())
+               );
 
+       trackview.editor().session()->set_dirty ();
+       did_push = false;
+
+       contiguous_points.clear ();
+}
 
 void
-AutomationLine::sync_model_with_view_point (ControlPoint& cp, bool did_push, int64_t distance)
+AutomationLine::sync_model_with_view_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
-       double ydelta;
-
-       model_representation (cp, mr);
-
-       /* how much are we changing the central point by */ 
-
-       ydelta = mr.yval - mr.ypos;
-
-       /*
-          apply the full change to the central point, and interpolate
-          on both axes to cover all model points represented
-          by the control point.
+       /* find out where the visual control point is.
+          initial results are in canvas units. ask the
+          line to convert them to something relevant.
        */
 
-       /* change all points before the primary point */
+       double view_x = cp.get_x();
+       double view_y = 1.0 - (cp.get_y() / _height);
 
-       for (AutomationList::iterator i = mr.start; i != cp.model(); ++i) {
-               
-               double fract = ((*i)->when - mr.xmin) / (mr.xpos - mr.xmin);
-               double y_delta = ydelta * fract;
-               double x_delta = distance * fract;
+       /* if xval has not changed, set it directly from the model to avoid rounding errors */
 
-               /* interpolate */
-               
-               if (y_delta || x_delta) {
-                       alist->modify (i, (*i)->when + x_delta, mr.ymin + y_delta);
-               }
+       if (view_x == trackview.editor().frame_to_unit_unrounded (_time_converter->to ((*cp.model())->when)) - _offset) {
+               view_x = (*cp.model())->when - _offset;
+       } else {
+               view_x = trackview.editor().unit_to_frame (view_x);
+               view_x = _time_converter->from (view_x + _offset);
        }
 
-       /* change the primary point */
-
        update_pending = true;
-       alist->modify (cp.model(), mr.xval, mr.yval);
 
+       view_to_model_coord_y (view_y);
 
-       /* change later points */
-       
-       AutomationList::iterator i = cp.model();
-       
-       ++i;
-       
-       while (i != mr.end) {
-               
-               double delta = ydelta * (mr.xmax - (*i)->when) / (mr.xmax - mr.xpos);
-
-               /* all later points move by the same distance along the x-axis as the main point */
-               
-               if (delta) {
-                       alist->modify (i, (*i)->when + distance, (*i)->value + delta);
-               }
-               
-               ++i;
-       }
-               
-       if (did_push) {
-
-               /* move all points after the range represented by the view by the same distance
-                  as the main point moved.
-               */
-
-               alist->slide (mr.end, drag_distance);
-       }
-
+       alist->modify (cp.model(), view_x, view_y);
 }
 
-bool 
+bool
 AutomationLine::control_points_adjacent (double xval, uint32_t & before, uint32_t& after)
 {
        ControlPoint *bcp = 0;
        ControlPoint *acp = 0;
        double unit_xval;
 
-       unit_xval = trackview.editor().frame_to_unit (xval);
+       unit_xval = trackview.editor().frame_to_unit_unrounded (xval);
 
        for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               
+
                if ((*i)->get_x() <= unit_xval) {
 
                        if (!bcp || (*i)->get_x() > bcp->get_x()) {
                                bcp = *i;
                                before = bcp->view_index();
-                       } 
+                       }
 
                } else if ((*i)->get_x() > unit_xval) {
                        acp = *i;
@@ -937,32 +788,31 @@ AutomationLine::control_points_adjacent (double xval, uint32_t & before, uint32_
 bool
 AutomationLine::is_last_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
+       // If the list is not empty, and the point is the last point in the list
 
-       model_representation (cp, mr);
+       if (alist->empty()) {
+               return false;
+       }
 
-       // If the list is not empty, and the point is the last point in the list
+       AutomationList::const_iterator i = alist->end();
+       --i;
 
-       if (!alist->empty() && mr.end == alist->end()) {
+       if (cp.model() == i) {
                return true;
        }
-       
+
        return false;
 }
 
 bool
 AutomationLine::is_first_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
-
-       model_representation (cp, mr);
-
        // If the list is not empty, and the point is the first point in the list
 
-       if (!alist->empty() && mr.start == alist->begin()) {
+       if (!alist->empty() && cp.model() == alist->begin()) {
                return true;
        }
-       
+
        return false;
 }
 
@@ -970,179 +820,95 @@ AutomationLine::is_first_point (ControlPoint& cp)
 void
 AutomationLine::remove_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
-
-       model_representation (cp, mr);
-
-       trackview.editor().current_session()->begin_reversible_command (_("remove control point"));
+       trackview.editor().session()->begin_reversible_command (_("remove control point"));
        XMLNode &before = alist->get_state();
 
-       alist->erase (mr.start, mr.end);
+       alist->erase (cp.model());
+       
+       trackview.editor().session()->add_command(
+               new MementoCommand<AutomationList> (memento_command_binder (), &before, &alist->get_state())
+               );
 
-       trackview.editor().current_session()->add_command(new MementoCommand<AutomationList>(
-                       *alist.get(), &before, &alist->get_state()));
-       trackview.editor().current_session()->commit_reversible_command ();
-       trackview.editor().current_session()->set_dirty ();
+       trackview.editor().session()->commit_reversible_command ();
+       trackview.editor().session()->set_dirty ();
 }
 
+/** Get selectable points within an area.
+ *  @param start Start position in session frames.
+ *  @param end End position in session frames.
+ *  @param bot Bottom y range, as a fraction of line height, where 0 is the bottom of the line.
+ *  @param top Top y range, as a fraction of line height, where 0 is the bottom of the line.
+ *  @param result Filled in with selectable things; in this case, ControlPoints.
+ */
 void
-AutomationLine::get_selectables (nframes_t& start, nframes_t& end,
-               double botfrac, double topfrac, list<Selectable*>& results)
+AutomationLine::get_selectables (framepos_t start, framepos_t end, double botfrac, double topfrac, list<Selectable*>& results)
 {
-
-       double top;
-       double bot;
-       double nstart;
-       double nend;
-       bool collecting = false;
-
-       /* Curse X11 and its inverted coordinate system! */
-       
-       bot = (1.0 - topfrac) * _height;
-       top = (1.0 - botfrac) * _height;
-       
-       nstart = max_frames;
-       nend = 0;
+       /* convert fractions to display coordinates with 0 at the top of the track */
+       double const bot_track = (1 - topfrac) * trackview.current_height ();
+       double const top_track = (1 - botfrac) * trackview.current_height ();
 
        for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               double when = (*(*i)->model())->when;
+               double const model_when = (*(*i)->model())->when;
 
-               if (when >= start && when <= end) {
-                       
-                       if ((*i)->get_y() >= bot && (*i)->get_y() <= top) {
-
-                               (*i)->show();
-                               (*i)->set_visible(true);
-                               collecting = true;
-                               nstart = min (nstart, when);
-                               nend = max (nend, when);
+               /* model_when is relative to the start of the source, so we just need to add on the origin_b here
+                  (as it is the session frame position of the start of the source)
+               */
+               
+               framepos_t const session_frames_when = _time_converter->to (model_when) + _time_converter->origin_b ();
 
-                       } else {
-                               
-                               if (collecting) {
-
-                                       results.push_back (new AutomationSelectable (nstart, nend, botfrac, topfrac, trackview));
-                                       collecting = false;
-                                       nstart = max_frames;
-                                       nend = 0;
-                               }
-                       }
+               if (session_frames_when >= start && session_frames_when <= end && (*i)->get_y() >= bot_track && (*i)->get_y() <= top_track) {
+                       results.push_back (*i);
                }
        }
-
-       if (collecting) {
-               results.push_back (new AutomationSelectable (nstart, nend, botfrac, topfrac, trackview));
-       }
-
 }
 
 void
-AutomationLine::get_inverted_selectables (Selection&, list<Selectable*>& results)
+AutomationLine::get_inverted_selectables (Selection&, list<Selectable*>& /*results*/)
 {
        // hmmm ....
 }
 
 void
-AutomationLine::set_selected_points (PointSelection& points)
+AutomationLine::set_selected_points (PointSelection const & points)
 {
-       double top;
-       double bot;
-
        for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-                       (*i)->set_selected(false);
+               (*i)->set_selected (false);
        }
 
-       if (points.empty()) {
-               goto out;
-       } 
-       
-       for (PointSelection::iterator r = points.begin(); r != points.end(); ++r) {
-               
-               if (&(*r).track != &trackview) {
-                       continue;
-               }
-
-               /* Curse X11 and its inverted coordinate system! */
-
-               bot = (1.0 - (*r).high_fract) * _height;
-               top = (1.0 - (*r).low_fract) * _height;
-
-               for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-                       
-                       double rstart, rend;
-                       
-                       rstart = trackview.editor().frame_to_unit ((*r).start);
-                       rend = trackview.editor().frame_to_unit ((*r).end);
-                       
-                       if ((*i)->get_x() >= rstart && (*i)->get_x() <= rend) {
-                               
-                               if ((*i)->get_y() >= bot && (*i)->get_y() <= top) {
-                                       
-                                       (*i)->set_selected(true);
-                               }
-                       }
-
-               }
-       }
-
-  out:
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               (*i)->show_color (false, !points_visible);
+       for (PointSelection::const_iterator i = points.begin(); i != points.end(); ++i) {
+               (*i)->set_selected (true);
        }
 
+       set_colors ();
 }
 
-void AutomationLine::set_colors() {
-       set_line_color( ARDOUR_UI::config()->canvasvar_AutomationLine.get() );
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               (*i)->show_color (false, !points_visible);
-       }
-}
-
-void
-AutomationLine::show_selection ()
+void AutomationLine::set_colors ()
 {
-       TimeSelection& time (trackview.editor().get_selection().time);
-
+       set_line_color (ARDOUR_UI::config()->canvasvar_AutomationLine.get());
        for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               
-               (*i)->set_selected(false);
-
-               for (list<AudioRange>::iterator r = time.begin(); r != time.end(); ++r) {
-                       double rstart, rend;
-                       
-                       rstart = trackview.editor().frame_to_unit ((*r).start);
-                       rend = trackview.editor().frame_to_unit ((*r).end);
-                       
-                       if ((*i)->get_x() >= rstart && (*i)->get_x() <= rend) {
-                               (*i)->set_selected(true);
-                               break;
-                       }
-               }
-               
-               (*i)->show_color (false, !points_visible);
+               (*i)->set_color ();
        }
 }
 
-void
-AutomationLine::hide_selection ()
-{
-//     show_selection ();
-}
-
 void
 AutomationLine::list_changed ()
 {
-       queue_reset ();
+       DEBUG_TRACE (DEBUG::Automation, string_compose ("\tline changed, existing update pending? %1\n", update_pending));
+
+       if (!update_pending) {
+               update_pending = true;
+               Gtkmm2ext::UI::instance()->call_slot (invalidator (*this), boost::bind (&AutomationLine::queue_reset, this));
+       }
 }
 
 void
 AutomationLine::reset_callback (const Evoral::ControlList& events)
 {
-       ALPoints tmp_points;
-       uint32_t npoints = events.size();
+       uint32_t vp = 0;
+       uint32_t pi = 0;
+       uint32_t np;
 
-       if (npoints == 0) {
+       if (events.empty()) {
                for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
                        delete *i;
                }
@@ -1151,32 +917,97 @@ AutomationLine::reset_callback (const Evoral::ControlList& events)
                return;
        }
 
-       AutomationList::const_iterator ai;
+       /* hide all existing points, and the line */
+
+       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+               (*i)->hide();
+       }
+
+       line->hide ();
+       np = events.size();
+
+       Evoral::ControlList& e = const_cast<Evoral::ControlList&> (events);
+       
+       for (AutomationList::iterator ai = e.begin(); ai != e.end(); ++ai, ++pi) {
+
+               double tx = (*ai)->when;
+               double ty = (*ai)->value;
 
-       for (ai = events.begin(); ai != events.end(); ++ai) {
+               /* convert from model coordinates to canonical view coordinates */
+
+               model_to_view_coord (tx, ty);
+
+               if (std::isnan (tx) || std::isnan (ty)) {
+                       warning << string_compose (_("Ignoring illegal points on AutomationLine \"%1\""),
+                                                  _name) << endmsg;
+                       continue;
+               }
                
-               double translated_x = (*ai)->when;
-               double translated_y = (*ai)->value;
-               model_to_view_coord (translated_x, translated_y);
+               if (tx >= max_framepos || tx < 0 || tx >= _maximum_time) {
+                       continue;
+               }
+               
+               /* convert x-coordinate to a canvas unit coordinate (this takes
+                * zoom and scroll into account).
+                */
+                       
+               tx = trackview.editor().frame_to_unit_unrounded (tx);
+               
+               /* convert from canonical view height (0..1.0) to actual
+                * height coordinates (using X11's top-left rooted system)
+                */
+
+               ty = _height - (ty * _height);
 
-               add_model_point (tmp_points, (*ai)->when, translated_y);
+               add_visible_control_point (vp, pi, tx, ty, ai, np);
+               vp++;
        }
-       
-       determine_visible_control_points (tmp_points);
-}
 
+       /* discard extra CP's to avoid confusing ourselves */
 
-void
-AutomationLine::add_model_point (ALPoints& tmp_points, double frame, double yfract)
-{
-       tmp_points.push_back (ALPoint (trackview.editor().frame_to_unit (_time_converter.to(frame)),
-                                      _height - (yfract * _height)));
+       while (control_points.size() > vp) {
+               ControlPoint* cp = control_points.back();
+               control_points.pop_back ();
+               delete cp;
+       }
+
+       if (!terminal_points_can_slide) {
+               control_points.back()->set_can_slide(false);
+       }
+
+       if (vp > 1) {
+
+               /* reset the line coordinates given to the CanvasLine */
+
+               while (line_points.size() < vp) {
+                       line_points.push_back (Art::Point (0,0));
+               }
+
+               while (line_points.size() > vp) {
+                       line_points.pop_back ();
+               }
+
+               for (uint32_t n = 0; n < vp; ++n) {
+                       line_points[n].set_x (control_points[n]->get_x());
+                       line_points[n].set_y (control_points[n]->get_y());
+               }
+
+               line->property_points() = line_points;
+
+               if (_visible && alist->interpolation() != AutomationList::Discrete) {
+                       line->show();
+               }
+       }
+
+       set_selected_points (trackview.editor().get_selection().points);
 }
 
 void
 AutomationLine::reset ()
 {
+       DEBUG_TRACE (DEBUG::Automation, "\t\tLINE RESET\n");
        update_pending = false;
+       have_timeout = false;
 
        if (no_draw) {
                return;
@@ -1185,63 +1016,78 @@ AutomationLine::reset ()
        alist->apply_to_points (*this, &AutomationLine::reset_callback);
 }
 
+void
+AutomationLine::queue_reset ()
+{
+       /* this must be called from the GUI thread
+        */
+
+       if (trackview.editor().session()->transport_rolling() && alist->automation_write()) {
+               /* automation write pass ... defer to a timeout */
+               /* redraw in 1/4 second */
+               if (!have_timeout) {
+                       DEBUG_TRACE (DEBUG::Automation, "\tqueue timeout\n");
+                       Glib::signal_timeout().connect (sigc::bind_return (sigc::mem_fun (*this, &AutomationLine::reset), false), 250);
+                       have_timeout = true;
+               } else {
+                       DEBUG_TRACE (DEBUG::Automation, "\ttimeout already queued, change ignored\n");
+               }
+       } else {
+               reset ();
+       }
+}
+
 void
 AutomationLine::clear ()
 {
-       /* parent must create command */
-       XMLNode &before = get_state();
+       /* parent must create and commit command */
+       XMLNode &before = alist->get_state();
        alist->clear();
-       trackview.editor().current_session()->add_command (
-                       new MementoCommand<AutomationLine>(*this, &before, &get_state()));
-       trackview.editor().current_session()->commit_reversible_command ();
-       trackview.editor().current_session()->set_dirty ();
+
+       trackview.editor().session()->add_command (
+               new MementoCommand<AutomationList> (memento_command_binder (), &before, &alist->get_state())
+               );
 }
 
 void
-AutomationLine::change_model (AutomationList::iterator i, double x, double y)
+AutomationLine::change_model (AutomationList::iterator /*i*/, double /*x*/, double /*y*/)
 {
 }
 
 void
-AutomationLine::set_list(boost::shared_ptr<ARDOUR::AutomationList> list)
+AutomationLine::set_list (boost::shared_ptr<ARDOUR::AutomationList> list)
 {
        alist = list;
-       queue_reset();
+       queue_reset ();
+       connect_to_list ();
 }
 
 void
-AutomationLine::show_all_control_points ()
+AutomationLine::add_visibility (VisibleAspects va)
 {
-       points_visible = true;
-
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               (*i)->show_color((_interpolation != AutomationList::Discrete), false);
-               (*i)->show ();
-               (*i)->set_visible (true);
-       }
+       _visible = VisibleAspects (_visible | va);
+       show ();
 }
 
 void
-AutomationLine::hide_all_but_selected_control_points ()
+AutomationLine::set_visibility (VisibleAspects va)
 {
-       if (alist->interpolation() == AutomationList::Discrete) {
-               return;
-       }
-
-       points_visible = false;
+       _visible = va;
+       show ();
+}
 
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               if (!(*i)->selected()) {
-                       (*i)->set_visible (false);
-               }
-       }
+void
+AutomationLine::remove_visibility (VisibleAspects va)
+{
+       _visible = VisibleAspects (_visible & ~va);
+       show ();
 }
-       
+
 void
 AutomationLine::track_entered()
 {
        if (alist->interpolation() != AutomationList::Discrete) {
-               show_all_control_points();
+               add_visibility (ControlPoints);
        }
 }
 
@@ -1249,7 +1095,7 @@ void
 AutomationLine::track_exited()
 {
        if (alist->interpolation() != AutomationList::Discrete) {
-               hide_all_but_selected_control_points();
+               remove_visibility (ControlPoints);
        }
 }
 
@@ -1260,32 +1106,38 @@ AutomationLine::get_state (void)
        return alist->get_state();
 }
 
-int 
-AutomationLine::set_state (const XMLNode &node)
+int
+AutomationLine::set_state (const XMLNode &node, int version)
 {
        /* function as a proxy for the model */
-       return alist->set_state (node);
+       return alist->set_state (node, version);
 }
 
 void
 AutomationLine::view_to_model_coord (double& x, double& y) const
+{
+       x = _time_converter->from (x);
+       view_to_model_coord_y (y);
+}
+
+void
+AutomationLine::view_to_model_coord_y (double& y) const
 {
        /* TODO: This should be more generic ... */
        if (alist->parameter().type() == GainAutomation ||
            alist->parameter().type() == EnvelopeAutomation) {
-               y = slider_position_to_gain (y);
+               y = slider_position_to_gain_with_max (y, Config->get_max_gain());
                y = max (0.0, y);
                y = min (2.0, y);
-       } else if (alist->parameter().type() == PanAutomation) {
-               // vertical coordinate axis reversal
+       } else if (alist->parameter().type() == PanAzimuthAutomation ||
+                   alist->parameter().type() == PanElevationAutomation ||
+                   alist->parameter().type() == PanWidthAutomation) {
                y = 1.0 - y;
        } else if (alist->parameter().type() == PluginAutomation) {
                y = y * (double)(alist->get_max_y()- alist->get_min_y()) + alist->get_min_y();
        } else {
-               y = (int)(y * alist->parameter().max());
+               y = rint (y * alist->parameter().max());
        }
-
-       x = _time_converter.from(x);
 }
 
 void
@@ -1294,8 +1146,10 @@ AutomationLine::model_to_view_coord (double& x, double& y) const
        /* TODO: This should be more generic ... */
        if (alist->parameter().type() == GainAutomation ||
            alist->parameter().type() == EnvelopeAutomation) {
-               y = gain_to_slider_position (y);
-       } else if (alist->parameter().type() == PanAutomation) {
+               y = gain_to_slider_position_with_max (y, Config->get_max_gain());
+       } else if (alist->parameter().type() == PanAzimuthAutomation ||
+                   alist->parameter().type() == PanElevationAutomation ||
+                   alist->parameter().type() == PanWidthAutomation) {
                // vertical coordinate axis reversal
                y = 1.0 - y;
        } else if (alist->parameter().type() == PluginAutomation) {
@@ -1303,22 +1157,130 @@ AutomationLine::model_to_view_coord (double& x, double& y) const
        } else {
                y = y / (double)alist->parameter().max(); /* ... like this */
        }
-       
-       x = _time_converter.to(x);
+
+       x = _time_converter->to (x) - _offset;
 }
 
-       
+/** Called when our list has announced that its interpolation style has changed */
 void
-AutomationLine::set_interpolation(AutomationList::InterpolationStyle style)
+AutomationLine::interpolation_changed (AutomationList::InterpolationStyle style)
 {
-       _interpolation = style;
-
        if (style == AutomationList::Discrete) {
-               show_all_control_points();
+               set_visibility (ControlPoints);
                line->hide();
        } else {
-               hide_all_but_selected_control_points();
-               line->show();
+               set_visibility (Line);
        }
 }
 
+void
+AutomationLine::add_visible_control_point (uint32_t view_index, uint32_t pi, double tx, double ty, 
+                                          AutomationList::iterator model, uint32_t npoints)
+{
+       ControlPoint::ShapeType shape;
+
+       if (view_index >= control_points.size()) {
+
+               /* make sure we have enough control points */
+
+               ControlPoint* ncp = new ControlPoint (*this);
+               ncp->set_size (control_point_box_size ());
+
+               control_points.push_back (ncp);
+       }
+
+       if (!terminal_points_can_slide) {
+               if (pi == 0) {
+                       control_points[view_index]->set_can_slide (false);
+                       if (tx == 0) {
+                               shape = ControlPoint::Start;
+                       } else {
+                               shape = ControlPoint::Full;
+                       }
+               } else if (pi == npoints - 1) {
+                       control_points[view_index]->set_can_slide (false);
+                       shape = ControlPoint::End;
+               } else {
+                       control_points[view_index]->set_can_slide (true);
+                       shape = ControlPoint::Full;
+               }
+       } else {
+               control_points[view_index]->set_can_slide (true);
+               shape = ControlPoint::Full;
+       }
+
+       control_points[view_index]->reset (tx, ty, model, view_index, shape);
+
+       /* finally, control visibility */
+
+       if (_visible & ControlPoints) {
+               control_points[view_index]->show ();
+               control_points[view_index]->set_visible (true);
+       } else {
+               control_points[view_index]->set_visible (false);
+       }
+}
+
+void
+AutomationLine::connect_to_list ()
+{
+       _list_connections.drop_connections ();
+
+       alist->StateChanged.connect (_list_connections, invalidator (*this), boost::bind (&AutomationLine::list_changed, this), gui_context());
+
+       alist->InterpolationChanged.connect (
+               _list_connections, invalidator (*this), boost::bind (&AutomationLine::interpolation_changed, this, _1), gui_context()
+               );
+}
+
+MementoCommandBinder<AutomationList>*
+AutomationLine::memento_command_binder ()
+{
+       return new SimpleMementoCommandBinder<AutomationList> (*alist.get());
+}
+
+/** Set the maximum time that points on this line can be at, relative
+ *  to the start of the track or region that it is on.
+ */
+void
+AutomationLine::set_maximum_time (framecnt_t t)
+{
+       if (_maximum_time == t) {
+               return;
+       }
+
+       _maximum_time = t;
+       reset ();
+}
+
+
+/** @return min and max x positions of points that are in the list, in session frames */
+pair<framepos_t, framepos_t>
+AutomationLine::get_point_x_range () const
+{
+       pair<framepos_t, framepos_t> r (max_framepos, 0);
+
+       for (AutomationList::const_iterator i = the_list()->begin(); i != the_list()->end(); ++i) {
+               r.first = min (r.first, session_position (i));
+               r.second = max (r.second, session_position (i));
+       }
+
+       return r;
+}
+
+framepos_t
+AutomationLine::session_position (AutomationList::const_iterator p) const
+{
+       return _time_converter->to ((*p)->when) + _offset + _time_converter->origin_b ();
+}
+
+void
+AutomationLine::set_offset (framepos_t off)
+{
+       if (_offset == off) {
+               return;
+       }
+
+       _offset = off;
+       reset ();
+}