ardour/gtk2_ardour/mini_timeline.cc

824 lines
21 KiB
C++

/*
* Copyright (C) 2016-2017 Robin Gareus <robin@gareus.org>
* Copyright (C) 2016-2018 Ben Loftis <ben@harrisonconsoles.com>
*
* 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
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "ardour/audioengine.h"
#include "ardour/session.h"
#include "ardour/tempo.h"
#include "gtkmm2ext/colors.h"
#include "gtkmm2ext/gui_thread.h"
#include "gtkmm2ext/keyboard.h"
#include "widgets/tooltips.h"
#include "ardour_ui.h"
#include "public_editor.h"
#include "main_clock.h"
#include "mini_timeline.h"
#include "timers.h"
#include "ui_config.h"
#include "pbd/i18n.h"
#define PADDING 3
#define BBT_BAR_CHAR "|"
using namespace ARDOUR;
MiniTimeline::MiniTimeline ()
: _last_update_sample (-1)
, _clock_mode (AudioClock::Timecode)
, _time_width (0)
, _time_height (0)
, _n_labels (0)
, _px_per_sample (0)
, _time_granularity (0)
, _time_span_samples (0)
, _marker_height (0)
, _pointer_x (-1)
, _pointer_y (-1)
, _minitl_context_menu (0)
{
add_events (Gdk::ENTER_NOTIFY_MASK|Gdk::LEAVE_NOTIFY_MASK|Gdk::BUTTON_RELEASE_MASK|Gdk::BUTTON_PRESS_MASK|Gdk::POINTER_MOTION_MASK|Gdk::SCROLL_MASK);
_layout = Pango::Layout::create (get_pango_context());
UIConfiguration::instance().ColorsChanged.connect (sigc::mem_fun (*this, &MiniTimeline::set_colors));
UIConfiguration::instance().DPIReset.connect (sigc::mem_fun (*this, &MiniTimeline::on_name_changed));
UIConfiguration::instance().DPIReset.connect (sigc::mem_fun (*this, &MiniTimeline::on_name_changed));
set_name ("minitimeline");
Location::name_changed.connect (marker_connection, invalidator (*this), boost::bind (&MiniTimeline::update_minitimeline, this), gui_context ());
Location::end_changed.connect (marker_connection, invalidator (*this), boost::bind (&MiniTimeline::update_minitimeline, this), gui_context ());
Location::start_changed.connect (marker_connection, invalidator (*this), boost::bind (&MiniTimeline::update_minitimeline, this), gui_context ());
Location::flags_changed.connect (marker_connection, invalidator (*this), boost::bind (&MiniTimeline::update_minitimeline, this), gui_context ());
ArdourWidgets::set_tooltip (*this,
string_compose (_("<b>Navigation Timeline</b>. Use left-click to locate to time position or marker; scroll-wheel to jump, hold %1 for fine grained and %2 + %3 for extra-fine grained control. Right-click to set display range. The display unit is defined by the primary clock."),
Gtkmm2ext::Keyboard::primary_modifier_name(),
Gtkmm2ext::Keyboard::primary_modifier_name (),
Gtkmm2ext::Keyboard::secondary_modifier_name ()));
}
MiniTimeline::~MiniTimeline ()
{
delete _minitl_context_menu;
_minitl_context_menu = 0;
}
void
MiniTimeline::session_going_away ()
{
super_rapid_connection.disconnect ();
session_connection.drop_connections ();
SessionHandlePtr::session_going_away ();
_jumplist.clear ();
delete _minitl_context_menu;
_minitl_context_menu = 0;
}
void
MiniTimeline::set_session (Session* s)
{
SessionHandlePtr::set_session (s);
if (!s) {
return;
}
assert (!super_rapid_connection.connected ());
super_rapid_connection = Timers::super_rapid_connect (
sigc::mem_fun (*this, &MiniTimeline::super_rapid_update)
);
_session->config.ParameterChanged.connect (session_connection,
invalidator (*this),
boost::bind (&MiniTimeline::parameter_changed, this, _1), gui_context()
);
_session->locations()->added.connect (session_connection,
invalidator (*this),
boost::bind (&MiniTimeline::update_minitimeline, this), gui_context()
);
_session->locations()->removed.connect (session_connection,
invalidator (*this),
boost::bind (&MiniTimeline::update_minitimeline, this), gui_context()
);
_session->locations()->changed.connect (session_connection,
invalidator (*this),
boost::bind (&MiniTimeline::update_minitimeline, this), gui_context()
);
_jumplist.clear ();
calculate_time_spacing ();
update_minitimeline ();
}
void
MiniTimeline::on_style_changed (const Glib::RefPtr<Gtk::Style>& old_style)
{
CairoWidget::on_style_changed (old_style);
set_colors ();
calculate_time_width ();
}
void
MiniTimeline::on_name_changed ()
{
set_colors ();
calculate_time_width ();
if (is_realized()) {
queue_resize ();
}
}
void
MiniTimeline::set_colors ()
{
// TODO UIConfiguration::instance().color & font
_phead_color = UIConfiguration::instance().color ("play head");
}
void
MiniTimeline::parameter_changed (std::string const& p)
{
if (p == "minitimeline-span") {
calculate_time_spacing ();
update_minitimeline ();
}
}
void
MiniTimeline::on_size_request (Gtk::Requisition* req)
{
req->width = req->height = 0;
CairoWidget::on_size_request (req);
req->width = std::max (req->width, 1);
req->height = std::max (req->height, 20);
}
void
MiniTimeline::on_size_allocate (Gtk::Allocation& alloc)
{
CairoWidget::on_size_allocate (alloc);
calculate_time_spacing ();
}
void
MiniTimeline::set_span (samplecnt_t ts)
{
assert (_session);
if (_session->config.get_minitimeline_span () == ts) {
return;
}
_session->config.set_minitimeline_span (ts);
calculate_time_spacing ();
update_minitimeline ();
}
void
MiniTimeline::super_rapid_update ()
{
if (!_session || !_session->engine().running() || !is_mapped ()) {
return;
}
samplepos_t const sample = PublicEditor::instance().playhead_cursor_sample ();
AudioClock::Mode m = ARDOUR_UI::instance()->primary_clock->mode();
bool change = false;
if (fabs ((_last_update_sample - sample) * _px_per_sample) >= 1.0) {
change = true;
}
if (m != _clock_mode) {
_clock_mode = m;
calculate_time_width ();
change = true;
}
if (_clock_mode == AudioClock::BBT) {
// TODO check if tempo-map changed
change = true;
}
if (change) {
_last_update_sample = sample;
update_minitimeline ();
}
}
void
MiniTimeline::update_minitimeline ()
{
CairoWidget::set_dirty ();
}
void
MiniTimeline::calculate_time_width ()
{
switch (_clock_mode) {
case AudioClock::Timecode:
_layout->set_text (" 88:88:88,888 ");
break;
case AudioClock::BBT:
_layout->set_text ("888|88|8888");
break;
case AudioClock::MinSec:
_layout->set_text ("88:88:88,88");
break;
case AudioClock::Seconds:
case AudioClock::Samples:
_layout->set_text ("8888888888");
break;
}
_layout->get_pixel_size (_time_width, _time_height);
}
void
MiniTimeline::calculate_time_spacing ()
{
_n_labels = floor (get_width () / (_time_width * 1.15));
if (_n_labels == 0 || !_session) {
return;
}
const samplecnt_t time_span = _session->config.get_minitimeline_span () / 2;
_time_span_samples = time_span * _session->nominal_sample_rate ();
_time_granularity = _session->nominal_sample_rate () * ceil (2. * time_span / _n_labels);
_px_per_sample = get_width () / (2. * _time_span_samples);
//_px_per_sample = 1.0 / round (1.0 / _px_per_sample);
}
void
MiniTimeline::format_time (samplepos_t when)
{
switch (_clock_mode) {
case AudioClock::Timecode:
{
Timecode::Time TC;
_session->timecode_time (when, TC);
// chop of leading space or minus.
_layout->set_text (Timecode::timecode_format_time (TC).substr(1));
}
break;
case AudioClock::BBT:
{
char buf[64];
Timecode::BBT_Time BBT = _session->tempo_map().bbt_at_sample (when);
snprintf (buf, sizeof (buf), "%03" PRIu32 BBT_BAR_CHAR "%02" PRIu32 BBT_BAR_CHAR "%04" PRIu32,
BBT.bars, BBT.beats, BBT.ticks);
_layout->set_text (buf);
}
break;
case AudioClock::MinSec:
{
char buf[32];
AudioClock::print_minsec (when, buf, sizeof (buf), _session->sample_rate());
_layout->set_text (std::string(buf).substr(1));
}
break;
case AudioClock::Seconds:
{
char buf[32];
snprintf (buf, sizeof (buf), "%.1f", when / (float)_session->sample_rate());
_layout->set_text (buf);
}
break;
case AudioClock::Samples:
{
char buf[32];
snprintf (buf, sizeof (buf), "%" PRId64, when);
_layout->set_text (buf);
}
break;
}
}
void
MiniTimeline::draw_dots (cairo_t* cr, int left, int right, int y, Gtkmm2ext::Color color)
{
if (left + 1 >= right) {
return;
}
cairo_move_to (cr, left + .5, y + .5);
cairo_line_to (cr, right - .5, y + .5);
Gtkmm2ext::set_source_rgb_a(cr, color, 0.3);
const double dashes[] = { 0, 1 };
cairo_set_dash (cr, dashes, 2, 1);
cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
cairo_set_line_width (cr, 1.0);
cairo_stroke (cr);
cairo_set_dash (cr, 0, 0, 0);
}
int
MiniTimeline::draw_mark (cairo_t* cr, int x0, int x1, const std::string& label, bool& prelight)
{
int h = _marker_height;
/* ArdourMarker shape
* MH = 13
*
* Mark:
*
* (0,0) -- (6,0)
* | |
* | |
* (0,MH*.4) (6,MH*.4)
* \ /
* (3,MH)
*/
const int y = PADDING;
int w2 = (h - 1) / 4;
double h0 = h * .4;
double h1 = h - h0;
int lw, lh;
_layout->set_text (label);
_layout->get_pixel_size (lw, lh);
int rw = std::min (x1, x0 + w2 + lw + 2);
if (_pointer_y >= 0 && _pointer_y <= y + h && _pointer_x >= x0 - w2 && _pointer_x <= rw) {
prelight = true;
}
// TODO cache in set_colors()
uint32_t color = UIConfiguration::instance().color (
prelight ? "entered marker" : "location marker");
double r, g, b, a;
Gtkmm2ext::color_to_rgba (color, r, g, b, a);
if (rw < x0) {
rw = x1;
} else {
cairo_save (cr);
cairo_rectangle (cr, x0, y, rw - x0, h);
cairo_set_source_rgba (cr, r, g, b, 0.5); // this should use a shaded color
cairo_fill_preserve (cr);
cairo_clip (cr);
// marker label
cairo_move_to (cr, x0 + w2, y + .5 * (h - lh));
cairo_set_source_rgb (cr, 0, 0, 0);
pango_cairo_show_layout (cr, _layout->gobj());
cairo_restore (cr);
}
// draw marker on top
cairo_move_to (cr, x0 - .5, y + .5);
cairo_rel_line_to (cr, -w2 , 0);
cairo_rel_line_to (cr, 0, h0);
cairo_rel_line_to (cr, w2, h1);
cairo_rel_line_to (cr, w2, -h1);
cairo_rel_line_to (cr, 0, -h0);
cairo_close_path (cr);
cairo_set_source_rgba (cr, r, g, b, 1.0);
cairo_set_line_width (cr, 1.0);
cairo_stroke_preserve (cr);
cairo_fill (cr);
return rw;
}
int
MiniTimeline::draw_edge (cairo_t* cr, int x0, int x1, bool left, const std::string& label, bool& prelight)
{
int h = _marker_height;
int w2 = (h - 1) / 4;
const int y = PADDING;
const double yc = rint (h * .5);
const double dy = h * .4;
bool with_label;
int lw, lh, lx;
_layout->set_text (label);
_layout->get_pixel_size (lw, lh);
double px, dx;
if (left) {
if (x0 + 2 * w2 + lw + 2 < x1) {
x1 = std::min (x1, x0 + 2 * w2 + lw + 2);
with_label = true;
} else {
x1 = std::min (x1, x0 + 2 * w2);
with_label = false;
}
px = x0;
dx = 2 * w2;
lx = x0 + dx;
} else {
if (x1 - 2 * w2 - lw - 2 > x0) {
x0 = std::max (x0, x1 - 2 * w2 - lw - 2);
with_label = true;
} else {
x0 = std::max (x0, x1 - 2 * w2);
with_label = false;
}
px = x1;
dx = -2 * w2;
lx = x1 + dx - lw - 2;
}
if (x1 - x0 < 2 * w2) {
return left ? x0 : x1;
}
if (_pointer_y >= 0 && _pointer_y <= y + h && _pointer_x >= x0 && _pointer_x <= x1) {
prelight = true;
}
// TODO cache in set_colors()
uint32_t color = UIConfiguration::instance().color (
prelight ? "entered marker" : "location marker");
double r, g, b, a;
Gtkmm2ext::color_to_rgba (color, r, g, b, a);
if (with_label) {
const int y = PADDING;
cairo_save (cr);
cairo_rectangle (cr, lx, y, lw + 2, h);
cairo_set_source_rgba (cr, r, g, b, 0.5); // this should use a shaded color
cairo_fill_preserve (cr);
cairo_clip (cr);
// marker label
cairo_move_to (cr, lx + 1, y + .5 * (h - lh));
cairo_set_source_rgb (cr, 0, 0, 0);
pango_cairo_show_layout (cr, _layout->gobj());
cairo_restore (cr);
}
// draw arrow
cairo_move_to (cr, px - .5, PADDING + yc - .5);
cairo_rel_line_to (cr, dx , dy);
cairo_rel_line_to (cr, 0, -2. * dy);
cairo_close_path (cr);
cairo_set_source_rgba (cr, r, g, b, 1.0);
cairo_set_line_width (cr, 1.0);
cairo_stroke_preserve (cr);
cairo_fill (cr);
return left ? x1 : x0;
}
struct LocationMarker {
LocationMarker (const std::string& l, samplepos_t w)
: label (l), when (w) {}
std::string label;
samplepos_t when;
};
struct LocationMarkerSort {
bool operator() (const LocationMarker& a, const LocationMarker& b) {
return (a.when < b.when);
}
};
void
MiniTimeline::render (Cairo::RefPtr<Cairo::Context> const& ctx, cairo_rectangle_t*)
{
cairo_t* cr = ctx->cobj();
// TODO cache, set_colors()
Gtkmm2ext::Color base = UIConfiguration::instance().color ("ruler base");
Gtkmm2ext::Color text = UIConfiguration::instance().color ("ruler text");
if (_n_labels == 0) {
return;
}
cairo_push_group (cr);
const int width = get_width ();
const int height = get_height ();
Gtkmm2ext::rounded_rectangle (cr, 0, 0, width, height, 4);
Gtkmm2ext::set_source_rgba(cr, base);
cairo_fill (cr);
Gtkmm2ext::rounded_rectangle (cr, PADDING, PADDING, width - PADDING - PADDING, height - PADDING - PADDING, 4);
cairo_clip (cr);
if (_session == 0) {
cairo_pop_group_to_source (cr);
cairo_paint (cr);
return;
}
/* time */
const samplepos_t p = _last_update_sample;
const samplepos_t lower = (std::max ((samplepos_t)0, (p - _time_span_samples)) / _time_granularity) * _time_granularity;
int dot_left = width * .5 + (lower - p) * _px_per_sample;
for (int i = 0; i < 2 + _n_labels; ++i) {
samplepos_t when = lower + i * _time_granularity;
double xpos = width * .5 + (when - p) * _px_per_sample;
// TODO round to nearest display TC in +/- 1px
// prefer to display BBT |0 or .0
int lw, lh;
format_time (when);
_layout->get_pixel_size (lw, lh);
int x0 = xpos - lw / 2.0;
int y0 = height - PADDING - _time_height;
draw_dots (cr, dot_left, x0, y0 + _time_height * .5, text);
cairo_move_to (cr, x0, y0);
Gtkmm2ext::set_source_rgba(cr, text);
pango_cairo_show_layout (cr, _layout->gobj());
dot_left = x0 + lw;
}
draw_dots (cr, dot_left, width, height - PADDING - _time_height * .5, text);
/* locations */
samplepos_t lmin = std::max ((samplepos_t)0, (p - _time_span_samples));
samplepos_t lmax = p + _time_span_samples;
int tw, th;
_layout->set_text (X_("Marker@"));
_layout->get_pixel_size (tw, th);
_marker_height = th + 2;
assert (_marker_height > 4);
const int mw = (_marker_height - 1) / 4;
lmin -= mw / _px_per_sample;
lmax += mw / _px_per_sample;
std::vector<LocationMarker> lm;
const Locations::LocationList& ll (_session->locations ()->list ());
for (Locations::LocationList::const_iterator l = ll.begin(); l != ll.end(); ++l) {
if ((*l)->is_session_range ()) {
lm.push_back (LocationMarker(_("start"), (*l)->start ()));
lm.push_back (LocationMarker(_("end"), (*l)->end ()));
continue;
}
if (!(*l)->is_mark () || (*l)->name().substr (0, 4) == "xrun") {
continue;
}
lm.push_back (LocationMarker((*l)->name(), (*l)->start ()));
}
_jumplist.clear ();
LocationMarkerSort location_marker_sort;
std::sort (lm.begin(), lm.end(), location_marker_sort);
std::vector<LocationMarker>::const_iterator outside_left = lm.end();
std::vector<LocationMarker>::const_iterator outside_right = lm.end();
int left_limit = 0;
int right_limit = width * .5 + mw;
int id = 0;
for (std::vector<LocationMarker>::const_iterator l = lm.begin(); l != lm.end(); ++id) {
samplepos_t when = (*l).when;
if (when < lmin) {
outside_left = l;
if (++l != lm.end()) {
left_limit = floor (width * .5 + ((*l).when - p) * _px_per_sample) - 1 - mw;
} else {
left_limit = width * .5 - mw;
}
continue;
}
if (when > lmax) {
outside_right = l;
break;
}
int x0 = floor (width * .5 + (when - p) * _px_per_sample);
int x1 = width;
const std::string& label = (*l).label;
if (++l != lm.end()) {
x1 = floor (width * .5 + ((*l).when - p) * _px_per_sample) - 1 - mw;
}
bool prelight = false;
x1 = draw_mark (cr, x0, x1, label, prelight);
_jumplist.push_back (JumpRange (x0 - mw, x1, when, prelight));
right_limit = std::max (x1, right_limit);
}
if (outside_left != lm.end ()) {
if (left_limit > 3 * mw + PADDING) {
int x0 = PADDING + 1;
int x1 = left_limit - mw;
bool prelight = false;
x1 = draw_edge (cr, x0, x1, true, (*outside_left).label, prelight);
if (x0 != x1) {
_jumplist.push_back (JumpRange (x0, x1, (*outside_left).when, prelight));
right_limit = std::max (x1, right_limit);
}
}
}
if (outside_right != lm.end ()) {
if (right_limit + PADDING < width - 3 * mw) {
int x0 = right_limit;
int x1 = width - PADDING;
bool prelight = false;
x0 = draw_edge (cr, x0, x1, false, (*outside_right).label, prelight);
if (x0 != x1) {
_jumplist.push_back (JumpRange (x0, x1, (*outside_right).when, prelight));
}
}
}
/* playhead on top */
int xc = width * 0.5f;
cairo_set_line_width (cr, 1.0);
double r,g,b,a; Gtkmm2ext::color_to_rgba(_phead_color, r,g,b,a);
cairo_set_source_rgb (cr, r,g,b); // playhead color
cairo_move_to (cr, xc - .5, 0);
cairo_rel_line_to (cr, 0, height);
cairo_stroke (cr);
cairo_move_to (cr, xc - .5, height);
cairo_rel_line_to (cr, -3, 0);
cairo_rel_line_to (cr, 3, -4);
cairo_rel_line_to (cr, 3, 4);
cairo_close_path (cr);
cairo_fill (cr);
cairo_pop_group_to_source (cr);
cairo_paint (cr);
}
void
MiniTimeline::build_minitl_context_menu ()
{
using namespace Gtk;
using namespace Gtk::Menu_Helpers;
assert (_session);
const samplecnt_t time_span = _session->config.get_minitimeline_span ();
_minitl_context_menu = new Gtk::Menu();
MenuList& items = _minitl_context_menu->items();
// ideally this would have a heading (or rather be a sub-menu to "Visible Time")
std::map<samplecnt_t, std::string> spans;
spans[30] = _("30 sec");
spans[60] = _("1 min");
spans[120] = _("2 mins");
spans[300] = _("5 mins");
spans[600] = _("10 mins");
spans[1200] = _("20 mins");
RadioMenuItem::Group span_group;
for (std::map<samplecnt_t, std::string>::const_iterator i = spans.begin (); i != spans.end (); ++i) {
items.push_back (RadioMenuElem (span_group, i->second, sigc::bind (sigc::mem_fun (*this, &MiniTimeline::set_span), i->first)));
if (time_span == i->first) {
static_cast<RadioMenuItem*>(&items.back())->set_active ();
}
}
}
bool
MiniTimeline::on_button_press_event (GdkEventButton *ev)
{
if (Gtkmm2ext::Keyboard::is_context_menu_event (ev)) {
if (_session) {
if (_minitl_context_menu == 0) {
build_minitl_context_menu ();
}
_minitl_context_menu->popup (ev->button, ev->time);
}
return true;
}
return true;
}
bool
MiniTimeline::on_button_release_event (GdkEventButton *ev)
{
if (!_session) { return true; }
if (_session->actively_recording ()) { return true; }
if (ev->y < 0 || ev->y > get_height () || ev->x < 0 || ev->x > get_width ()) {
return true;
}
if (ev->y <= PADDING + _marker_height) {
for (JumpList::const_iterator i = _jumplist.begin (); i != _jumplist.end(); ++i) {
if (i->left <= ev->x && ev->x <= i->right) {
_session->request_locate (i->to, RollIfAppropriate);
return true;
}
}
}
if (ev->button == 1) {
samplepos_t when = _last_update_sample + (ev->x - get_width() * .5) / _px_per_sample;
_session->request_locate (std::max ((samplepos_t)0, when), RollIfAppropriate);
}
return true;
}
bool
MiniTimeline::on_motion_notify_event (GdkEventMotion *ev)
{
if (!_session) { return true; }
if (_session->actively_recording ()) { return true; }
_pointer_x = ev->x;
_pointer_y = ev->y;
bool need_expose = false;
for (JumpList::const_iterator i = _jumplist.begin (); i != _jumplist.end(); ++i) {
if (i->left < ev->x && ev->x < i->right && ev->y <= PADDING + _marker_height) {
if (!(*i).prelight) {
need_expose = true;
break;
}
} else {
if ((*i).prelight) {
need_expose = true;
break;
}
}
}
if (need_expose) {
update_minitimeline ();
}
return true;
}
bool
MiniTimeline::on_leave_notify_event (GdkEventCrossing *ev)
{
CairoWidget::on_leave_notify_event (ev);
_pointer_x = _pointer_y = -1;
for (JumpList::const_iterator i = _jumplist.begin (); i != _jumplist.end(); ++i) {
if ((*i).prelight) {
update_minitimeline ();
break;
}
}
return true;
}
bool
MiniTimeline::on_scroll_event (GdkEventScroll *ev)
{
if (!_session) { return true; }
if (_session->actively_recording ()) { return true; }
const samplecnt_t time_span = _session->config.get_minitimeline_span ();
samplepos_t when = _session->audible_sample ();
double scale = time_span / 60.0;
if (ev->state & Gtkmm2ext::Keyboard::GainFineScaleModifier) {
if (ev->state & Gtkmm2ext::Keyboard::GainExtraFineScaleModifier) {
scale = 0.1;
} else {
scale = 0.5;
}
}
switch (ev->direction) {
case GDK_SCROLL_UP:
case GDK_SCROLL_RIGHT:
when += scale * _session->nominal_sample_rate ();
break;
case GDK_SCROLL_DOWN:
case GDK_SCROLL_LEFT:
when -= scale * _session->nominal_sample_rate ();
break;
default:
return true;
break;
}
_session->request_locate (std::max ((samplepos_t)0, when), RollIfAppropriate);
return true;
}