src/wx/audio_mapping_view.cc

   1 /*
   2     Copyright (C) 2013-2019 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 <dcp/locale_convert.h>
  31 #include <dcp/types.h>
  32 #include <wx/wx.h>
  33 #include <wx/renderer.h>
  34 #include <wx/grid.h>
  35 #include <wx/graphics.h>
  36 #include <boost/foreach.hpp>
  37 #include <iostream>
  38
  39 using std::cout;
  40 using std::list;
  41 using std::string;
  42 using std::min;
  43 using std::max;
  44 using std::vector;
  45 using std::pair;
  46 using std::make_pair;
  47 using boost::shared_ptr;
  48 using boost::optional;
  49 #if BOOST_VERSION >= 106100
  50 using namespace boost::placeholders;
  51 #endif
  52 using dcp::locale_convert;
  53
  54 #define INDICATOR_SIZE 20
  55 #define GRID_SPACING 32
  56 #define LEFT_WIDTH (GRID_SPACING * 3)
  57 #define TOP_HEIGHT (GRID_SPACING * 2)
  58
  59 enum {
  60         ID_off = 1,
  61         ID_full = 2,
  62         ID_minus6dB = 3,
  63         ID_edit = 4
  64 };
  65
  66 AudioMappingView::AudioMappingView (wxWindow* parent)
  67         : wxPanel (parent, wxID_ANY)
  68         , _menu_input (0)
  69         , _menu_output (1)
  70 {
  71         _menu = new wxMenu;
  72         _menu->Append (ID_off, _("Off"));
  73         _menu->Append (ID_full, _("Full"));
  74         _menu->Append (ID_minus6dB, _("-6dB"));
  75         _menu->Append (ID_edit, _("Edit..."));
  76
  77         _body = new wxPanel (this, wxID_ANY);
  78         _vertical_scroll = new wxScrollBar (this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxSB_VERTICAL);
  79         _horizontal_scroll = new wxScrollBar (this, wxID_ANY);
  80
  81         Bind (wxEVT_SIZE, boost::bind(&AudioMappingView::size, this, _1));
  82         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::off, this), ID_off);
  83         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::full, this), ID_full);
  84         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::minus6dB, this), ID_minus6dB);
  85         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::edit, this), ID_edit);
  86         Bind (wxEVT_MOUSEWHEEL, boost::bind(&AudioMappingView::mouse_wheel, this, _1));
  87         _body->Bind (wxEVT_PAINT, boost::bind(&AudioMappingView::paint, this));
  88         _body->Bind (wxEVT_LEFT_DOWN, boost::bind(&AudioMappingView::left_down, this, _1));
  89         _body->Bind (wxEVT_RIGHT_DOWN, boost::bind(&AudioMappingView::right_down, this, _1));
  90         _body->Bind (wxEVT_MOTION, boost::bind(&AudioMappingView::motion, this, _1));
  91         _vertical_scroll->Bind (wxEVT_SCROLL_TOP, boost::bind(&AudioMappingView::scroll, this));
  92         _vertical_scroll->Bind (wxEVT_SCROLL_BOTTOM, boost::bind(&AudioMappingView::scroll, this));
  93         _vertical_scroll->Bind (wxEVT_SCROLL_LINEUP, boost::bind(&AudioMappingView::scroll, this));
  94         _vertical_scroll->Bind (wxEVT_SCROLL_LINEDOWN, boost::bind(&AudioMappingView::scroll, this));
  95         _vertical_scroll->Bind (wxEVT_SCROLL_PAGEUP, boost::bind(&AudioMappingView::scroll, this));
  96         _vertical_scroll->Bind (wxEVT_SCROLL_PAGEDOWN, boost::bind(&AudioMappingView::scroll, this));
  97         _vertical_scroll->Bind (wxEVT_SCROLL_THUMBTRACK, boost::bind(&AudioMappingView::scroll, this));
  98         _vertical_scroll->Bind (wxEVT_SCROLL_THUMBRELEASE, boost::bind(&AudioMappingView::scroll, this));
  99         _horizontal_scroll->Bind (wxEVT_SCROLL_TOP, boost::bind(&AudioMappingView::scroll, this));
 100         _horizontal_scroll->Bind (wxEVT_SCROLL_BOTTOM, boost::bind(&AudioMappingView::scroll, this));
 101         _horizontal_scroll->Bind (wxEVT_SCROLL_LINEUP, boost::bind(&AudioMappingView::scroll, this));
 102         _horizontal_scroll->Bind (wxEVT_SCROLL_LINEDOWN, boost::bind(&AudioMappingView::scroll, this));
 103         _horizontal_scroll->Bind (wxEVT_SCROLL_PAGEUP, boost::bind(&AudioMappingView::scroll, this));
 104         _horizontal_scroll->Bind (wxEVT_SCROLL_PAGEDOWN, boost::bind(&AudioMappingView::scroll, this));
 105         _horizontal_scroll->Bind (wxEVT_SCROLL_THUMBTRACK, boost::bind(&AudioMappingView::scroll, this));
 106         _horizontal_scroll->Bind (wxEVT_SCROLL_THUMBRELEASE, boost::bind(&AudioMappingView::scroll, this));
 107 }
 108
 109 void
 110 AudioMappingView::size (wxSizeEvent& ev)
 111 {
 112         setup ();
 113         ev.Skip ();
 114 }
 115
 116 void
 117 AudioMappingView::setup ()
 118 {
 119         wxSize const s = GetSize();
 120         int const w = _vertical_scroll->GetSize().GetWidth();
 121         int const h = _horizontal_scroll->GetSize().GetHeight();
 122
 123         _vertical_scroll->SetPosition (wxPoint(s.GetWidth() - w, 0));
 124         _vertical_scroll->SetSize (wxSize(w, max(0, s.GetHeight() - h)));
 125
 126         _body->SetSize (wxSize(max(0, s.GetWidth() - w), max(0, s.GetHeight() - h)));
 127
 128         _horizontal_scroll->SetPosition (wxPoint(0, s.GetHeight() - h));
 129         _horizontal_scroll->SetSize (wxSize(max(0, s.GetWidth() - w), h));
 130
 131         _vertical_scroll->SetScrollbar (
 132                 _vertical_scroll->GetThumbPosition(),
 133                 s.GetHeight() - h - 8,
 134                 GRID_SPACING * (2 + _input_channels.size()),
 135                 GRID_SPACING,
 136                 true
 137                 );
 138
 139         _horizontal_scroll->SetScrollbar (
 140                 _horizontal_scroll->GetThumbPosition(),
 141                 s.GetWidth() - w - 8,
 142                 GRID_SPACING * (3 + _output_channels.size()),
 143                 GRID_SPACING,
 144                 true);
 145 }
 146
 147 void
 148 AudioMappingView::scroll ()
 149 {
 150         Refresh ();
 151 }
 152
 153 void
 154 AudioMappingView::paint_static (wxDC& dc, wxGraphicsContext* gc)
 155 {
 156         gc->SetAntialiasMode (wxANTIALIAS_DEFAULT);
 157         dc.SetFont (wxSWISS_FONT->Bold());
 158         wxCoord label_width;
 159         wxCoord label_height;
 160
 161         /* DCP label at the top */
 162
 163         dc.GetTextExtent (_("DCP"), &label_width, &label_height);
 164         dc.DrawText (_("DCP"), LEFT_WIDTH + (_output_channels.size() * GRID_SPACING - label_width) / 2, (GRID_SPACING - label_height) / 2);
 165
 166         /* Content label on the left */
 167
 168         dc.GetTextExtent (_("Content"), &label_width, &label_height);
 169         dc.DrawRotatedText (
 170                 _("Content"),
 171                 (GRID_SPACING - label_height) / 2,
 172                 TOP_HEIGHT + (_input_channels.size() * GRID_SPACING + label_width) / 2,
 173                 90
 174                 );
 175
 176         dc.SetFont (*wxSWISS_FONT);
 177         gc->SetPen (*wxBLACK_PEN);
 178 }
 179
 180 void
 181 AudioMappingView::paint_column_labels (wxDC& dc, wxGraphicsContext* gc)
 182 {
 183         wxCoord label_width;
 184         wxCoord label_height;
 185         int N = 0;
 186         BOOST_FOREACH (string i, _output_channels) {
 187                 dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
 188                 dc.DrawText (std_to_wx(i), LEFT_WIDTH + GRID_SPACING * N + (GRID_SPACING - label_width) / 2, GRID_SPACING + (GRID_SPACING - label_height) / 2);
 189                 ++N;
 190         }
 191
 192         wxGraphicsPath lines = gc->CreatePath ();
 193         lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING);
 194         lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING);
 195         lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING * 2);
 196         lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING * 2);
 197         gc->StrokePath (lines);
 198 }
 199
 200 void
 201 AudioMappingView::paint_column_lines (wxGraphicsContext* gc)
 202 {
 203         wxGraphicsPath lines = gc->CreatePath ();
 204         for (size_t i = 0; i < _output_channels.size(); ++i) {
 205                 lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * i, GRID_SPACING);
 206                 lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
 207         }
 208         lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), GRID_SPACING);
 209         lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
 210         gc->StrokePath (lines);
 211 }
 212
 213 void
 214 AudioMappingView::paint_row_labels (wxDC& dc, wxGraphicsContext* gc)
 215 {
 216         wxCoord label_width;
 217         wxCoord label_height;
 218         wxGraphicsPath lines = gc->CreatePath ();
 219
 220         /* Row channel labels */
 221
 222         int N = 0;
 223         BOOST_FOREACH (string i, _input_channels) {
 224                 dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
 225                 dc.DrawText (std_to_wx(i), GRID_SPACING * 2 + (GRID_SPACING - label_width) / 2, TOP_HEIGHT + GRID_SPACING * N + (GRID_SPACING - label_height) / 2);
 226                 ++N;
 227         }
 228
 229         /* Vertical lines on the left */
 230
 231         for (int i = 1; i < 3; ++i) {
 232                 lines.MoveToPoint    (GRID_SPACING * i, TOP_HEIGHT);
 233                 lines.AddLineToPoint (GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
 234         }
 235
 236         /* Group labels and lines */
 237
 238         int y = TOP_HEIGHT;
 239         BOOST_FOREACH (Group i, _input_groups) {
 240                 int const height = (i.to - i.from + 1) * GRID_SPACING;
 241                 dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
 242                 if (label_width > height) {
 243                         label_width = height - 8;
 244                 }
 245
 246                 {
 247                         int yp = y;
 248                         if ((yp - 2 * GRID_SPACING) < dc.GetLogicalOrigin().y) {
 249                                 yp += dc.GetLogicalOrigin().y;
 250                         }
 251
 252                         wxCoord old_x, old_y, old_width, old_height;
 253                         dc.GetClippingBox (&old_x, &old_y, &old_width, &old_height);
 254                         dc.DestroyClippingRegion ();
 255                         dc.SetClippingRegion (GRID_SPACING, yp + 4, GRID_SPACING, height - 8);
 256
 257                         dc.DrawRotatedText (
 258                                 std_to_wx(i.name),
 259                                 GRID_SPACING + (GRID_SPACING - label_height) / 2,
 260                                 y + (height + label_width) / 2,
 261                                 90
 262                                 );
 263
 264                         dc.DestroyClippingRegion ();
 265                         dc.SetClippingRegion (old_x, old_y, old_width, old_height);
 266                 }
 267
 268                 lines.MoveToPoint    (GRID_SPACING,     y);
 269                 lines.AddLineToPoint (GRID_SPACING * 2, y);
 270                 y += height;
 271         }
 272
 273         lines.MoveToPoint    (GRID_SPACING,     y);
 274         lines.AddLineToPoint (GRID_SPACING * 2, y);
 275
 276         gc->StrokePath (lines);
 277 }
 278
 279 void
 280 AudioMappingView::paint_row_lines (wxGraphicsContext* gc)
 281 {
 282         wxGraphicsPath lines = gc->CreatePath ();
 283         for (size_t i = 0; i < _input_channels.size(); ++i) {
 284                 lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * i);
 285                 lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * i);
 286         }
 287         lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
 288         lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
 289         gc->StrokePath (lines);
 290 }
 291
 292 void
 293 AudioMappingView::paint_indicators (wxDC& dc)
 294 {
 295         /* _{input,output}_channels and _map may not always be in sync, be careful here */
 296         size_t const output = min(_output_channels.size(), size_t(_map.output_channels()));
 297         size_t const input = min(_input_channels.size(), size_t(_map.input_channels()));
 298
 299         for (size_t x = 0; x < output; ++x) {
 300                 for (size_t y = 0; y < input; ++y) {
 301                         dc.SetBrush (*wxWHITE_BRUSH);
 302                         dc.DrawRectangle (
 303                                 wxRect(
 304                                         LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 305                                         TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 306                                         INDICATOR_SIZE, INDICATOR_SIZE
 307                                         )
 308                                 );
 309
 310                         float const value_dB = 20 * log10 (_map.get(y, x));
 311                         int const range = 18;
 312                         int height = 0;
 313                         if (value_dB > -range) {
 314                                 height = INDICATOR_SIZE * (1 + value_dB / range);
 315                         }
 316
 317                         dc.SetBrush (*wxTheBrushList->FindOrCreateBrush(wxColour (0, 255, 0), wxBRUSHSTYLE_SOLID));
 318                         dc.DrawRectangle (
 319                                 wxRect(
 320                                         LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 321                                         TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2 + INDICATOR_SIZE - height,
 322                                         INDICATOR_SIZE, height
 323                                         )
 324                                 );
 325                 }
 326         }
 327 }
 328
 329 static
 330 void clip (wxDC& dc, wxGraphicsContext* gc, int x, int y, int w, int h)
 331 {
 332         dc.SetClippingRegion (x, y, w, h);
 333         gc->Clip (x, y, w, h);
 334 }
 335
 336 static
 337 void translate (wxDC& dc, wxGraphicsContext* gc, int x, int y)
 338 {
 339         gc->PushState ();
 340         gc->Translate (-x, -y);
 341         dc.SetLogicalOrigin (x, y);
 342 }
 343
 344 static
 345 void restore (wxDC& dc, wxGraphicsContext* gc)
 346 {
 347         dc.SetLogicalOrigin (0, 0);
 348         gc->PopState ();
 349         dc.DestroyClippingRegion ();
 350         gc->ResetClip ();
 351 }
 352
 353 void
 354 AudioMappingView::paint ()
 355 {
 356         wxPaintDC dc (_body);
 357
 358         wxGraphicsContext* gc = wxGraphicsContext::Create (dc);
 359         if (!gc) {
 360                 return;
 361         }
 362
 363         int const hs = _horizontal_scroll->GetThumbPosition ();
 364         int const vs = _vertical_scroll->GetThumbPosition ();
 365
 366         paint_static (dc, gc);
 367
 368         clip (dc, gc, LEFT_WIDTH, 0, GRID_SPACING * _output_channels.size(), GRID_SPACING * (2 + _input_channels.size()));
 369         translate (dc, gc, hs, 0);
 370         paint_column_labels (dc, gc);
 371         restore (dc, gc);
 372
 373         clip (dc, gc, 0, TOP_HEIGHT, GRID_SPACING * (3 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
 374         translate (dc, gc, 0, vs);
 375         paint_row_labels (dc, gc);
 376         restore (dc, gc);
 377
 378         clip (dc, gc, GRID_SPACING * 2, TOP_HEIGHT, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
 379         translate (dc, gc, hs, vs);
 380         paint_row_lines (gc);
 381         restore (dc, gc);
 382
 383         clip (dc, gc, LEFT_WIDTH, GRID_SPACING, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * (1 + _input_channels.size()));
 384         translate (dc, gc, hs, vs);
 385         paint_column_lines (gc);
 386         restore (dc, gc);
 387
 388         clip (dc, gc, LEFT_WIDTH, TOP_HEIGHT, GRID_SPACING * _output_channels.size(), GRID_SPACING * _input_channels.size());
 389         translate (dc, gc, hs, vs);
 390         paint_indicators (dc);
 391         restore (dc, gc);
 392
 393         delete gc;
 394 }
 395
 396 optional<pair<int, int> >
 397 AudioMappingView::mouse_event_to_channels (wxMouseEvent& ev) const
 398 {
 399         int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
 400         int const y = ev.GetY() + _vertical_scroll->GetThumbPosition();
 401
 402         if (x <= LEFT_WIDTH || y < TOP_HEIGHT) {
 403                 return optional<pair<int, int> >();
 404         }
 405
 406         int const input = (y - TOP_HEIGHT) / GRID_SPACING;
 407         int const output = (x - LEFT_WIDTH) / GRID_SPACING;
 408
 409         if (input >= int(_input_channels.size()) || output >= int(_output_channels.size())) {
 410                 return optional<pair<int, int> >();
 411         }
 412
 413         return make_pair (input, output);
 414 }
 415
 416 optional<string>
 417 AudioMappingView::mouse_event_to_input_group_name (wxMouseEvent& ev) const
 418 {
 419         int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
 420         if (x < GRID_SPACING || x > (2 * GRID_SPACING)) {
 421                 return optional<string>();
 422         }
 423
 424         int y = (ev.GetY() + _vertical_scroll->GetThumbPosition() - (GRID_SPACING * 2)) / GRID_SPACING;
 425         BOOST_FOREACH (Group i, _input_groups) {
 426                 if (i.from <= y && y <= i.to) {
 427                         return i.name;
 428                 }
 429         }
 430
 431         return optional<string>();
 432 }
 433
 434 void
 435 AudioMappingView::left_down (wxMouseEvent& ev)
 436 {
 437         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 438         if (!channels) {
 439                 return;
 440         }
 441
 442         if (_map.get(channels->first, channels->second) > 0) {
 443                 _map.set (channels->first, channels->second, 0);
 444         } else {
 445                 _map.set (channels->first, channels->second, 1);
 446         }
 447
 448         map_values_changed ();
 449 }
 450
 451 void
 452 AudioMappingView::right_down (wxMouseEvent& ev)
 453 {
 454         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 455         if (!channels) {
 456                 return;
 457         }
 458
 459         _menu_input = channels->first;
 460         _menu_output = channels->second;
 461         PopupMenu (_menu, ev.GetPosition());
 462 }
 463
 464 void
 465 AudioMappingView::mouse_wheel (wxMouseEvent& ev)
 466 {
 467         if (ev.ShiftDown()) {
 468                 _horizontal_scroll->SetThumbPosition (
 469                         _horizontal_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
 470                         );
 471
 472         } else {
 473                 _vertical_scroll->SetThumbPosition (
 474                         _vertical_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
 475                         );
 476         }
 477         Refresh ();
 478 }
 479
 480 /** Called when any gain value has changed */
 481 void
 482 AudioMappingView::map_values_changed ()
 483 {
 484         Changed (_map);
 485         _last_tooltip_channels = optional<pair<int, int> >();
 486         Refresh ();
 487 }
 488
 489 void
 490 AudioMappingView::off ()
 491 {
 492         _map.set (_menu_input, _menu_output, 0);
 493         map_values_changed ();
 494 }
 495
 496 void
 497 AudioMappingView::full ()
 498 {
 499         _map.set (_menu_input, _menu_output, 1);
 500         map_values_changed ();
 501 }
 502
 503 void
 504 AudioMappingView::minus6dB ()
 505 {
 506         _map.set (_menu_input, _menu_output, pow (10, -6.0 / 20));
 507         map_values_changed ();
 508 }
 509
 510 void
 511 AudioMappingView::edit ()
 512 {
 513         AudioGainDialog* dialog = new AudioGainDialog (this, _menu_input, _menu_output, _map.get(_menu_input, _menu_output));
 514         if (dialog->ShowModal() == wxID_OK) {
 515                 _map.set (_menu_input, _menu_output, dialog->value ());
 516                 map_values_changed ();
 517         }
 518
 519         dialog->Destroy ();
 520 }
 521
 522 void
 523 AudioMappingView::set (AudioMapping map)
 524 {
 525         _map = map;
 526         Refresh ();
 527 }
 528
 529 void
 530 AudioMappingView::set_input_channels (vector<string> const & names)
 531 {
 532         _input_channels = names;
 533         setup ();
 534         Refresh ();
 535 }
 536
 537 void
 538 AudioMappingView::set_output_channels (vector<string> const & names)
 539 {
 540         _output_channels = names;
 541         setup ();
 542         Refresh ();
 543 }
 544
 545 void
 546 AudioMappingView::motion (wxMouseEvent& ev)
 547 {
 548         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 549         if (channels) {
 550                 if (channels != _last_tooltip_channels) {
 551                         wxString s;
 552                         float const gain = _map.get(channels->first, channels->second);
 553                         if (gain == 0) {
 554                                 s = wxString::Format (
 555                                         _("No audio will be passed from content channel %d to DCP channel %d."),
 556                                         channels->first + 1, channels->second + 1
 557                                         );
 558                         } else if (gain == 1) {
 559                                 s = wxString::Format (
 560                                         _("Audio will be passed from content channel %d to DCP channel %d unaltered."),
 561                                         channels->first + 1, channels->second + 1
 562                                         );
 563                         } else {
 564                                 float const dB = 20 * log10 (gain);
 565                                 s = wxString::Format (
 566                                         _("Audio will be passed from content channel %d to DCP channel %d with gain %.1fdB."),
 567                                         channels->first + 1, channels->second + 1, dB
 568                                         );
 569                         }
 570
 571                         SetToolTip (s + " " + _("Right click to change gain."));
 572                 }
 573         } else {
 574                 optional<string> group = mouse_event_to_input_group_name (ev);
 575                 if (group) {
 576                         SetToolTip (std_to_wx(*group));
 577                 } else {
 578                         SetToolTip ("");
 579                 }
 580         }
 581
 582         _last_tooltip_channels = channels;
 583         ev.Skip ();
 584 }
 585
 586 void
 587 AudioMappingView::set_input_groups (vector<Group> const & groups)
 588 {
 589         _input_groups = groups;
 590 }