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