src/wx/audio_mapping_view.cc

   1 /*
   2     Copyright (C) 2013-2020 Carl Hetherington <cth@carlh.net>
   3
   4     This file is part of DCP-o-matic.
   5
   6     DCP-o-matic is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     DCP-o-matic is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 /** @file  src/wx/audio_mapping_view.cc
  22  *  @brief AudioMappingView class and helpers.
  23  */
  24
  25 #include "audio_mapping_view.h"
  26 #include "wx_util.h"
  27 #include "audio_gain_dialog.h"
  28 #include "lib/audio_mapping.h"
  29 #include "lib/util.h"
  30 #include "lib/warnings.h"
  31 #include <dcp/locale_convert.h>
  32 #include <dcp/types.h>
  33 DCPOMATIC_DISABLE_WARNINGS
  34 #include <wx/wx.h>
  35 #include <wx/renderer.h>
  36 #include <wx/grid.h>
  37 #include <wx/graphics.h>
  38 DCPOMATIC_ENABLE_WARNINGS
  39 #include <boost/foreach.hpp>
  40 #include <iostream>
  41
  42 using std::cout;
  43 using std::list;
  44 using std::string;
  45 using std::min;
  46 using std::max;
  47 using std::vector;
  48 using std::pair;
  49 using std::make_pair;
  50 using boost::shared_ptr;
  51 using boost::optional;
  52 #if BOOST_VERSION >= 106100
  53 using namespace boost::placeholders;
  54 #endif
  55 using dcp::locale_convert;
  56
  57 #define INDICATOR_SIZE 20
  58 #define GRID_SPACING 32
  59 #define LEFT_WIDTH (GRID_SPACING * 3)
  60 #define TOP_HEIGHT (GRID_SPACING * 2)
  61
  62 enum {
  63         ID_off = 1,
  64         ID_minus6dB = 2,
  65         ID_0dB = 3,
  66         ID_plus3dB = 4,
  67         ID_edit = 5
  68 };
  69
  70 AudioMappingView::AudioMappingView (wxWindow* parent, wxString left_label, wxString from, wxString top_label, wxString to)
  71         : wxPanel (parent, wxID_ANY)
  72         , _menu_input (0)
  73         , _menu_output (1)
  74         , _left_label (left_label)
  75         , _from (from)
  76         , _top_label (top_label)
  77         , _to (to)
  78 {
  79         _menu = new wxMenu;
  80         _menu->Append (ID_off, _("Off"));
  81         _menu->Append (ID_minus6dB, _("-6dB"));
  82         _menu->Append (ID_0dB, _("0dB (unchanged)"));
  83         _menu->Append (ID_plus3dB, _("+3dB"));
  84         _menu->Append (ID_edit, _("Edit..."));
  85
  86         _body = new wxPanel (this, wxID_ANY);
  87         _vertical_scroll = new wxScrollBar (this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxSB_VERTICAL);
  88         _horizontal_scroll = new wxScrollBar (this, wxID_ANY);
  89
  90 #ifndef __WXOSX__
  91         SetDoubleBuffered (true);
  92 #endif
  93
  94         Bind (wxEVT_SIZE, boost::bind(&AudioMappingView::size, this, _1));
  95         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 0), ID_off);
  96         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(-6)), ID_minus6dB);
  97         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 1), ID_0dB);
  98         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(3)), ID_plus3dB);
  99         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::edit, this), ID_edit);
 100         Bind (wxEVT_MOUSEWHEEL, boost::bind(&AudioMappingView::mouse_wheel, this, _1));
 101         _body->Bind (wxEVT_PAINT, boost::bind(&AudioMappingView::paint, this));
 102         _body->Bind (wxEVT_LEFT_DOWN, boost::bind(&AudioMappingView::left_down, this, _1));
 103         _body->Bind (wxEVT_RIGHT_DOWN, boost::bind(&AudioMappingView::right_down, this, _1));
 104         _body->Bind (wxEVT_MOTION, boost::bind(&AudioMappingView::motion, this, _1));
 105         _vertical_scroll->Bind (wxEVT_SCROLL_TOP, boost::bind(&AudioMappingView::scroll, this));
 106         _vertical_scroll->Bind (wxEVT_SCROLL_BOTTOM, boost::bind(&AudioMappingView::scroll, this));
 107         _vertical_scroll->Bind (wxEVT_SCROLL_LINEUP, boost::bind(&AudioMappingView::scroll, this));
 108         _vertical_scroll->Bind (wxEVT_SCROLL_LINEDOWN, boost::bind(&AudioMappingView::scroll, this));
 109         _vertical_scroll->Bind (wxEVT_SCROLL_PAGEUP, boost::bind(&AudioMappingView::scroll, this));
 110         _vertical_scroll->Bind (wxEVT_SCROLL_PAGEDOWN, boost::bind(&AudioMappingView::scroll, this));
 111         _vertical_scroll->Bind (wxEVT_SCROLL_THUMBTRACK, boost::bind(&AudioMappingView::scroll, this));
 112         _vertical_scroll->Bind (wxEVT_SCROLL_THUMBRELEASE, boost::bind(&AudioMappingView::scroll, this));
 113         _horizontal_scroll->Bind (wxEVT_SCROLL_TOP, boost::bind(&AudioMappingView::scroll, this));
 114         _horizontal_scroll->Bind (wxEVT_SCROLL_BOTTOM, boost::bind(&AudioMappingView::scroll, this));
 115         _horizontal_scroll->Bind (wxEVT_SCROLL_LINEUP, boost::bind(&AudioMappingView::scroll, this));
 116         _horizontal_scroll->Bind (wxEVT_SCROLL_LINEDOWN, boost::bind(&AudioMappingView::scroll, this));
 117         _horizontal_scroll->Bind (wxEVT_SCROLL_PAGEUP, boost::bind(&AudioMappingView::scroll, this));
 118         _horizontal_scroll->Bind (wxEVT_SCROLL_PAGEDOWN, boost::bind(&AudioMappingView::scroll, this));
 119         _horizontal_scroll->Bind (wxEVT_SCROLL_THUMBTRACK, boost::bind(&AudioMappingView::scroll, this));
 120         _horizontal_scroll->Bind (wxEVT_SCROLL_THUMBRELEASE, boost::bind(&AudioMappingView::scroll, this));
 121 }
 122
 123 void
 124 AudioMappingView::size (wxSizeEvent& ev)
 125 {
 126         setup ();
 127         ev.Skip ();
 128 }
 129
 130 void
 131 AudioMappingView::setup ()
 132 {
 133         wxSize const s = GetSize();
 134         int const w = _vertical_scroll->GetSize().GetWidth();
 135         int const h = _horizontal_scroll->GetSize().GetHeight();
 136
 137         _vertical_scroll->SetPosition (wxPoint(s.GetWidth() - w, 0));
 138         _vertical_scroll->SetSize (wxSize(w, max(0, s.GetHeight() - h)));
 139
 140         _body->SetSize (wxSize(max(0, s.GetWidth() - w), max(0, s.GetHeight() - h)));
 141
 142         _horizontal_scroll->SetPosition (wxPoint(0, s.GetHeight() - h));
 143         _horizontal_scroll->SetSize (wxSize(max(0, s.GetWidth() - w), h));
 144
 145         _vertical_scroll->SetScrollbar (
 146                 _vertical_scroll->GetThumbPosition(),
 147                 s.GetHeight() - h - 8,
 148                 GRID_SPACING * (2 + _input_channels.size()),
 149                 GRID_SPACING,
 150                 true
 151                 );
 152
 153         _horizontal_scroll->SetScrollbar (
 154                 _horizontal_scroll->GetThumbPosition(),
 155                 s.GetWidth() - w - 8,
 156                 GRID_SPACING * (3 + _output_channels.size()),
 157                 GRID_SPACING,
 158                 true);
 159 }
 160
 161 void
 162 AudioMappingView::scroll ()
 163 {
 164         Refresh ();
 165 }
 166
 167 void
 168 AudioMappingView::paint_static (wxDC& dc)
 169 {
 170         dc.SetFont (wxSWISS_FONT->Bold());
 171         wxCoord label_width;
 172         wxCoord label_height;
 173
 174         dc.GetTextExtent (_top_label, &label_width, &label_height);
 175         dc.DrawText (_top_label, LEFT_WIDTH + (_output_channels.size() * GRID_SPACING - label_width) / 2, (GRID_SPACING - label_height) / 2);
 176
 177         dc.GetTextExtent (_left_label, &label_width, &label_height);
 178         dc.DrawRotatedText (
 179                 _left_label,
 180                 (GRID_SPACING - label_height) / 2,
 181                 TOP_HEIGHT + (_input_channels.size() * GRID_SPACING + label_width) / 2,
 182                 90
 183                 );
 184
 185         dc.SetFont (*wxSWISS_FONT);
 186 }
 187
 188 void
 189 AudioMappingView::paint_column_labels (wxDC& dc)
 190 {
 191         wxCoord label_width;
 192         wxCoord label_height;
 193         int N = 0;
 194         BOOST_FOREACH (string i, _output_channels) {
 195                 dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
 196                 dc.DrawText (std_to_wx(i), LEFT_WIDTH + GRID_SPACING * N + (GRID_SPACING - label_width) / 2, GRID_SPACING + (GRID_SPACING - label_height) / 2);
 197                 ++N;
 198         }
 199
 200         dc.DrawLine(wxPoint(LEFT_WIDTH, GRID_SPACING), wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING));
 201         dc.DrawLine(wxPoint(LEFT_WIDTH, GRID_SPACING * 2), wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING * 2));
 202 }
 203
 204 void
 205 AudioMappingView::paint_column_lines (wxDC& dc)
 206 {
 207         for (size_t i = 0; i < _output_channels.size(); ++i) {
 208                 dc.DrawLine (
 209                         wxPoint(LEFT_WIDTH + GRID_SPACING * i, GRID_SPACING),
 210                         wxPoint(LEFT_WIDTH + GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING)
 211                         );
 212         }
 213
 214         dc.DrawLine (
 215                 wxPoint(LEFT_WIDTH + GRID_SPACING * _output_channels.size(), GRID_SPACING),
 216                 wxPoint(LEFT_WIDTH + GRID_SPACING * _output_channels.size(), TOP_HEIGHT + _input_channels.size() * GRID_SPACING)
 217                 );
 218 }
 219
 220 void
 221 AudioMappingView::paint_row_labels (wxDC& dc)
 222 {
 223         wxCoord label_width;
 224         wxCoord label_height;
 225
 226         /* Row channel labels */
 227
 228         int N = 0;
 229         BOOST_FOREACH (string i, _input_channels) {
 230                 dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
 231                 dc.DrawText (std_to_wx(i), GRID_SPACING * 2 + (GRID_SPACING - label_width) / 2, TOP_HEIGHT + GRID_SPACING * N + (GRID_SPACING - label_height) / 2);
 232                 ++N;
 233         }
 234
 235         /* Vertical lines on the left */
 236
 237         for (int i = 1; i < 3; ++i) {
 238                 dc.DrawLine (
 239                         wxPoint(GRID_SPACING * i, TOP_HEIGHT),
 240                         wxPoint(GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING)
 241                         );
 242         }
 243
 244         /* Group labels and lines */
 245
 246         int y = TOP_HEIGHT;
 247         BOOST_FOREACH (Group i, _input_groups) {
 248                 int const height = (i.to - i.from + 1) * GRID_SPACING;
 249                 dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
 250                 if (label_width > height) {
 251                         label_width = height - 8;
 252                 }
 253
 254                 {
 255                         int yp = y;
 256                         if ((yp - 2 * GRID_SPACING) < dc.GetLogicalOrigin().y) {
 257                                 yp += dc.GetLogicalOrigin().y;
 258                         }
 259
 260                         dc.DrawRotatedText (
 261                                 std_to_wx(i.name),
 262                                 GRID_SPACING + (GRID_SPACING - label_height) / 2,
 263                                 y + (height + label_width) / 2,
 264                                 90
 265                                 );
 266                 }
 267
 268                 dc.DrawLine (wxPoint(GRID_SPACING, y), wxPoint(GRID_SPACING * 2, y));
 269                 y += height;
 270         }
 271
 272         dc.DrawLine (wxPoint(GRID_SPACING, y), wxPoint(GRID_SPACING * 2, y));
 273         }
 274
 275 void
 276 AudioMappingView::paint_row_lines (wxDC& dc)
 277 {
 278         for (size_t i = 0; i < _input_channels.size(); ++i) {
 279                 dc.DrawLine (
 280                         wxPoint(GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * i),
 281                         wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * i)
 282                         );
 283         }
 284         dc.DrawLine (
 285                 wxPoint(GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * _input_channels.size()),
 286                 wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * _input_channels.size())
 287                 );
 288 }
 289
 290 void
 291 AudioMappingView::paint_indicators (wxDC& dc)
 292 {
 293         /* _{input,output}_channels and _map may not always be in sync, be careful here */
 294         size_t const output = min(_output_channels.size(), size_t(_map.output_channels()));
 295         size_t const input = min(_input_channels.size(), size_t(_map.input_channels()));
 296
 297         for (size_t x = 0; x < output; ++x) {
 298                 for (size_t y = 0; y < input; ++y) {
 299                         dc.SetBrush (*wxWHITE_BRUSH);
 300                         dc.DrawRectangle (
 301                                 wxRect(
 302                                         LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 303                                         TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 304                                         INDICATOR_SIZE, INDICATOR_SIZE
 305                                         )
 306                                 );
 307
 308                         float const value_dB = linear_to_db(_map.get(y, x));
 309                         wxColour const colour = value_dB <= 0 ? wxColour(0, 255, 0) : wxColour(255, 150, 0);
 310                         int const range = 18;
 311                         int height = 0;
 312                         if (value_dB > -range) {
 313                                 height = min(INDICATOR_SIZE, static_cast<int>(INDICATOR_SIZE * (1 + value_dB / range)));
 314                         }
 315
 316                         dc.SetBrush (*wxTheBrushList->FindOrCreateBrush(colour, wxBRUSHSTYLE_SOLID));
 317                         dc.DrawRectangle (
 318                                 wxRect(
 319                                         LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 320                                         TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2 + INDICATOR_SIZE - height,
 321                                         INDICATOR_SIZE, height
 322                                         )
 323                                 );
 324                 }
 325         }
 326 }
 327
 328 static
 329 void clip (wxDC& dc, int x, int y, int w, int h)
 330 {
 331         dc.SetClippingRegion (x, y, w, h);
 332 }
 333
 334 static
 335 void translate (wxDC& dc, int x, int y)
 336 {
 337         dc.SetLogicalOrigin (x, y);
 338 }
 339
 340 static
 341 void restore (wxDC& dc)
 342 {
 343         dc.SetLogicalOrigin (0, 0);
 344         dc.DestroyClippingRegion ();
 345 }
 346
 347 void
 348 AudioMappingView::paint ()
 349 {
 350         wxPaintDC dc (_body);
 351
 352         int const hs = _horizontal_scroll->GetThumbPosition ();
 353         int const vs = _vertical_scroll->GetThumbPosition ();
 354
 355         paint_static (dc);
 356
 357         clip (
 358                 dc,
 359                 LEFT_WIDTH,
 360                 0,
 361                 GRID_SPACING * _output_channels.size(),
 362                 GRID_SPACING * (2 + _input_channels.size())
 363              );
 364         translate (dc, hs, 0);
 365         paint_column_labels (dc);
 366         restore (dc);
 367
 368         clip (
 369                 dc,
 370                 0,
 371                 TOP_HEIGHT,
 372                 GRID_SPACING * 3,
 373                 min(int(GRID_SPACING * _input_channels.size()), GetSize().GetHeight() - TOP_HEIGHT)
 374              );
 375         translate (dc, 0, vs);
 376         paint_row_labels (dc);
 377         restore (dc);
 378
 379         clip (
 380                 dc,
 381                 GRID_SPACING * 2,
 382                 TOP_HEIGHT,
 383                 GRID_SPACING * (1 + _output_channels.size()),
 384                 min(int(GRID_SPACING * (2 + _input_channels.size())), GetSize().GetHeight() - TOP_HEIGHT)
 385              );
 386         translate (dc, hs, vs);
 387         paint_row_lines (dc);
 388         restore (dc);
 389
 390         clip (
 391                 dc,
 392                 LEFT_WIDTH,
 393                 GRID_SPACING,
 394                 GRID_SPACING * (1 + _output_channels.size()),
 395                 min(int(GRID_SPACING * (1 + _input_channels.size())), GetSize().GetHeight() - GRID_SPACING)
 396              );
 397         translate (dc, hs, vs);
 398         paint_column_lines (dc);
 399         restore (dc);
 400
 401         clip (
 402                 dc,
 403                 LEFT_WIDTH,
 404                 TOP_HEIGHT,
 405                 GRID_SPACING * _output_channels.size(),
 406                 min(int(GRID_SPACING * _input_channels.size()), GetSize().GetHeight() - TOP_HEIGHT)
 407              );
 408         translate (dc, hs, vs);
 409         paint_indicators (dc);
 410         restore (dc);
 411 }
 412
 413 optional<pair<int, int> >
 414 AudioMappingView::mouse_event_to_channels (wxMouseEvent& ev) const
 415 {
 416         int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
 417         int const y = ev.GetY() + _vertical_scroll->GetThumbPosition();
 418
 419         if (x <= LEFT_WIDTH || y < TOP_HEIGHT) {
 420                 return optional<pair<int, int> >();
 421         }
 422
 423         int const input = (y - TOP_HEIGHT) / GRID_SPACING;
 424         int const output = (x - LEFT_WIDTH) / GRID_SPACING;
 425
 426         if (input >= int(_input_channels.size()) || output >= int(_output_channels.size())) {
 427                 return optional<pair<int, int> >();
 428         }
 429
 430         return make_pair (input, output);
 431 }
 432
 433 optional<string>
 434 AudioMappingView::mouse_event_to_input_group_name (wxMouseEvent& ev) const
 435 {
 436         int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
 437         if (x < GRID_SPACING || x > (2 * GRID_SPACING)) {
 438                 return optional<string>();
 439         }
 440
 441         int y = (ev.GetY() + _vertical_scroll->GetThumbPosition() - (GRID_SPACING * 2)) / GRID_SPACING;
 442         BOOST_FOREACH (Group i, _input_groups) {
 443                 if (i.from <= y && y <= i.to) {
 444                         return i.name;
 445                 }
 446         }
 447
 448         return optional<string>();
 449 }
 450
 451 void
 452 AudioMappingView::left_down (wxMouseEvent& ev)
 453 {
 454         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 455         if (!channels) {
 456                 return;
 457         }
 458
 459         if (_map.get(channels->first, channels->second) > 0) {
 460                 _map.set (channels->first, channels->second, 0);
 461         } else {
 462                 _map.set (channels->first, channels->second, 1);
 463         }
 464
 465         map_values_changed ();
 466 }
 467
 468 void
 469 AudioMappingView::right_down (wxMouseEvent& ev)
 470 {
 471         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 472         if (!channels) {
 473                 return;
 474         }
 475
 476         _menu_input = channels->first;
 477         _menu_output = channels->second;
 478         PopupMenu (_menu, ev.GetPosition());
 479 }
 480
 481 void
 482 AudioMappingView::mouse_wheel (wxMouseEvent& ev)
 483 {
 484         if (ev.ShiftDown()) {
 485                 _horizontal_scroll->SetThumbPosition (
 486                         _horizontal_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
 487                         );
 488
 489         } else {
 490                 _vertical_scroll->SetThumbPosition (
 491                         _vertical_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
 492                         );
 493         }
 494         Refresh ();
 495 }
 496
 497 /** Called when any gain value has changed */
 498 void
 499 AudioMappingView::map_values_changed ()
 500 {
 501         Changed (_map);
 502         _last_tooltip_channels = optional<pair<int, int> >();
 503         Refresh ();
 504 }
 505
 506 void
 507 AudioMappingView::set_gain_from_menu (double linear)
 508 {
 509         _map.set (_menu_input, _menu_output, linear);
 510         map_values_changed ();
 511 }
 512
 513 void
 514 AudioMappingView::edit ()
 515 {
 516         AudioGainDialog* dialog = new AudioGainDialog (this, _menu_input, _menu_output, _map.get(_menu_input, _menu_output));
 517         if (dialog->ShowModal() == wxID_OK) {
 518                 _map.set (_menu_input, _menu_output, dialog->value ());
 519                 map_values_changed ();
 520         }
 521
 522         dialog->Destroy ();
 523 }
 524
 525 void
 526 AudioMappingView::set (AudioMapping map)
 527 {
 528         _map = map;
 529         Refresh ();
 530 }
 531
 532 void
 533 AudioMappingView::set_input_channels (vector<string> const & names)
 534 {
 535         _input_channels = names;
 536         setup ();
 537         Refresh ();
 538 }
 539
 540 void
 541 AudioMappingView::set_output_channels (vector<string> const & names)
 542 {
 543         _output_channels = names;
 544         setup ();
 545         Refresh ();
 546 }
 547
 548 wxString
 549 AudioMappingView::safe_input_channel_name (int n) const
 550 {
 551         if (n >= int(_input_channels.size())) {
 552                 return wxString::Format ("%d", n + 1);
 553         }
 554
 555         optional<wxString> group;
 556         BOOST_FOREACH (Group i, _input_groups) {
 557                 if (i.from <= n && n <= i.to) {
 558                         group = std_to_wx (i.name);
 559                 }
 560         }
 561
 562         if (group && !group->IsEmpty()) {
 563                 return wxString::Format ("%s/%s", group->data(), std_to_wx(_input_channels[n]).data());
 564         }
 565
 566         return std_to_wx(_input_channels[n]);
 567 }
 568
 569 wxString
 570 AudioMappingView::safe_output_channel_name (int n) const
 571 {
 572         if (n >= int(_output_channels.size())) {
 573                 return wxString::Format ("%d", n + 1);
 574         }
 575
 576         return std_to_wx(_output_channels[n]);
 577 }
 578
 579 void
 580 AudioMappingView::motion (wxMouseEvent& ev)
 581 {
 582         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 583         if (channels) {
 584                 if (channels != _last_tooltip_channels) {
 585                         wxString s;
 586                         float const gain = _map.get(channels->first, channels->second);
 587                         if (gain == 0) {
 588                                 s = wxString::Format (
 589                                         _("No audio will be passed from %s channel '%s' to %s channel '%s'."),
 590                                         _from,
 591                                         safe_input_channel_name(channels->first),
 592                                         _to,
 593                                         safe_output_channel_name(channels->second)
 594                                         );
 595                         } else if (gain == 1) {
 596                                 s = wxString::Format (
 597                                         _("Audio will be passed from %s channel %s to %s channel %s unaltered."),
 598                                         _from,
 599                                         safe_input_channel_name(channels->first),
 600                                         _to,
 601                                         safe_output_channel_name(channels->second)
 602                                         );
 603                         } else {
 604                                 float const dB = linear_to_db(gain);
 605                                 s = wxString::Format (
 606                                         _("Audio will be passed from %s channel %s to %s channel %s with gain %.1fdB."),
 607                                         _from,
 608                                         safe_input_channel_name(channels->first),
 609                                         _to,
 610                                         safe_output_channel_name(channels->second),
 611                                         dB
 612                                         );
 613                         }
 614
 615                         SetToolTip (s + " " + _("Right click to change gain."));
 616                 }
 617         } else {
 618                 optional<string> group = mouse_event_to_input_group_name (ev);
 619                 if (group) {
 620                         SetToolTip (std_to_wx(*group));
 621                 } else {
 622                         SetToolTip ("");
 623                 }
 624         }
 625
 626         _last_tooltip_channels = channels;
 627         ev.Skip ();
 628 }
 629
 630 void
 631 AudioMappingView::set_input_groups (vector<Group> const & groups)
 632 {
 633         _input_groups = groups;
 634 }