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_minus6dB = 2,
  59         ID_0dB = 3,
  60         ID_plus3dB = 4,
  61         ID_edit = 5
  62 };
  63
  64 AudioMappingView::AudioMappingView (wxWindow* parent, wxString left_label, wxString from, wxString top_label, wxString to)
  65         : wxPanel (parent, wxID_ANY)
  66         , _menu_input (0)
  67         , _menu_output (1)
  68         , _left_label (left_label)
  69         , _from (from)
  70         , _top_label (top_label)
  71         , _to (to)
  72 {
  73         _menu = new wxMenu;
  74         _menu->Append (ID_off, _("Off"));
  75         _menu->Append (ID_minus6dB, _("-6dB"));
  76         _menu->Append (ID_0dB, _("0dB (unchanged)"));
  77         _menu->Append (ID_plus3dB, _("+3dB"));
  78         _menu->Append (ID_edit, _("Edit..."));
  79
  80         _body = new wxPanel (this, wxID_ANY);
  81         _vertical_scroll = new wxScrollBar (this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxSB_VERTICAL);
  82         _horizontal_scroll = new wxScrollBar (this, wxID_ANY);
  83
  84 #ifndef __WXOSX__
  85         SetDoubleBuffered (true);
  86 #endif
  87
  88         Bind (wxEVT_SIZE, boost::bind(&AudioMappingView::size, this, _1));
  89         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 0), ID_off);
  90         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(-6)), ID_minus6dB);
  91         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 1), ID_0dB);
  92         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(3)), ID_plus3dB);
  93         Bind (wxEVT_MENU, boost::bind(&AudioMappingView::edit, this), ID_edit);
  94         Bind (wxEVT_MOUSEWHEEL, boost::bind(&AudioMappingView::mouse_wheel, this, _1));
  95         _body->Bind (wxEVT_PAINT, boost::bind(&AudioMappingView::paint, this));
  96         _body->Bind (wxEVT_LEFT_DOWN, boost::bind(&AudioMappingView::left_down, this, _1));
  97         _body->Bind (wxEVT_RIGHT_DOWN, boost::bind(&AudioMappingView::right_down, this, _1));
  98         _body->Bind (wxEVT_MOTION, boost::bind(&AudioMappingView::motion, this, _1));
  99         _vertical_scroll->Bind (wxEVT_SCROLL_TOP, boost::bind(&AudioMappingView::scroll, this));
 100         _vertical_scroll->Bind (wxEVT_SCROLL_BOTTOM, boost::bind(&AudioMappingView::scroll, this));
 101         _vertical_scroll->Bind (wxEVT_SCROLL_LINEUP, boost::bind(&AudioMappingView::scroll, this));
 102         _vertical_scroll->Bind (wxEVT_SCROLL_LINEDOWN, boost::bind(&AudioMappingView::scroll, this));
 103         _vertical_scroll->Bind (wxEVT_SCROLL_PAGEUP, boost::bind(&AudioMappingView::scroll, this));
 104         _vertical_scroll->Bind (wxEVT_SCROLL_PAGEDOWN, boost::bind(&AudioMappingView::scroll, this));
 105         _vertical_scroll->Bind (wxEVT_SCROLL_THUMBTRACK, boost::bind(&AudioMappingView::scroll, this));
 106         _vertical_scroll->Bind (wxEVT_SCROLL_THUMBRELEASE, boost::bind(&AudioMappingView::scroll, this));
 107         _horizontal_scroll->Bind (wxEVT_SCROLL_TOP, boost::bind(&AudioMappingView::scroll, this));
 108         _horizontal_scroll->Bind (wxEVT_SCROLL_BOTTOM, boost::bind(&AudioMappingView::scroll, this));
 109         _horizontal_scroll->Bind (wxEVT_SCROLL_LINEUP, boost::bind(&AudioMappingView::scroll, this));
 110         _horizontal_scroll->Bind (wxEVT_SCROLL_LINEDOWN, boost::bind(&AudioMappingView::scroll, this));
 111         _horizontal_scroll->Bind (wxEVT_SCROLL_PAGEUP, boost::bind(&AudioMappingView::scroll, this));
 112         _horizontal_scroll->Bind (wxEVT_SCROLL_PAGEDOWN, boost::bind(&AudioMappingView::scroll, this));
 113         _horizontal_scroll->Bind (wxEVT_SCROLL_THUMBTRACK, boost::bind(&AudioMappingView::scroll, this));
 114         _horizontal_scroll->Bind (wxEVT_SCROLL_THUMBRELEASE, boost::bind(&AudioMappingView::scroll, this));
 115 }
 116
 117 void
 118 AudioMappingView::size (wxSizeEvent& ev)
 119 {
 120         setup ();
 121         ev.Skip ();
 122 }
 123
 124 void
 125 AudioMappingView::setup ()
 126 {
 127         wxSize const s = GetSize();
 128         int const w = _vertical_scroll->GetSize().GetWidth();
 129         int const h = _horizontal_scroll->GetSize().GetHeight();
 130
 131         _vertical_scroll->SetPosition (wxPoint(s.GetWidth() - w, 0));
 132         _vertical_scroll->SetSize (wxSize(w, max(0, s.GetHeight() - h)));
 133
 134         _body->SetSize (wxSize(max(0, s.GetWidth() - w), max(0, s.GetHeight() - h)));
 135
 136         _horizontal_scroll->SetPosition (wxPoint(0, s.GetHeight() - h));
 137         _horizontal_scroll->SetSize (wxSize(max(0, s.GetWidth() - w), h));
 138
 139         _vertical_scroll->SetScrollbar (
 140                 _vertical_scroll->GetThumbPosition(),
 141                 s.GetHeight() - h - 8,
 142                 GRID_SPACING * (2 + _input_channels.size()),
 143                 GRID_SPACING,
 144                 true
 145                 );
 146
 147         _horizontal_scroll->SetScrollbar (
 148                 _horizontal_scroll->GetThumbPosition(),
 149                 s.GetWidth() - w - 8,
 150                 GRID_SPACING * (3 + _output_channels.size()),
 151                 GRID_SPACING,
 152                 true);
 153 }
 154
 155 void
 156 AudioMappingView::scroll ()
 157 {
 158         Refresh ();
 159 }
 160
 161 void
 162 AudioMappingView::paint_static (wxDC& dc, wxGraphicsContext* gc)
 163 {
 164         gc->SetAntialiasMode (wxANTIALIAS_DEFAULT);
 165         dc.SetFont (wxSWISS_FONT->Bold());
 166         wxCoord label_width;
 167         wxCoord label_height;
 168
 169         dc.GetTextExtent (_top_label, &label_width, &label_height);
 170         dc.DrawText (_top_label, LEFT_WIDTH + (_output_channels.size() * GRID_SPACING - label_width) / 2, (GRID_SPACING - label_height) / 2);
 171
 172         dc.GetTextExtent (_left_label, &label_width, &label_height);
 173         dc.DrawRotatedText (
 174                 _left_label,
 175                 (GRID_SPACING - label_height) / 2,
 176                 TOP_HEIGHT + (_input_channels.size() * GRID_SPACING + label_width) / 2,
 177                 90
 178                 );
 179
 180         dc.SetFont (*wxSWISS_FONT);
 181         gc->SetPen (*wxBLACK_PEN);
 182 }
 183
 184 void
 185 AudioMappingView::paint_column_labels (wxDC& dc, wxGraphicsContext* gc)
 186 {
 187         wxCoord label_width;
 188         wxCoord label_height;
 189         int N = 0;
 190         BOOST_FOREACH (string i, _output_channels) {
 191                 dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
 192                 dc.DrawText (std_to_wx(i), LEFT_WIDTH + GRID_SPACING * N + (GRID_SPACING - label_width) / 2, GRID_SPACING + (GRID_SPACING - label_height) / 2);
 193                 ++N;
 194         }
 195
 196         wxGraphicsPath lines = gc->CreatePath ();
 197         lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING);
 198         lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING);
 199         lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING * 2);
 200         lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING * 2);
 201         gc->StrokePath (lines);
 202 }
 203
 204 void
 205 AudioMappingView::paint_column_lines (wxGraphicsContext* gc)
 206 {
 207         wxGraphicsPath lines = gc->CreatePath ();
 208         for (size_t i = 0; i < _output_channels.size(); ++i) {
 209                 lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * i, GRID_SPACING);
 210                 lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
 211         }
 212         lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), GRID_SPACING);
 213         lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
 214         gc->StrokePath (lines);
 215 }
 216
 217 void
 218 AudioMappingView::paint_row_labels (wxDC& dc, wxGraphicsContext* gc)
 219 {
 220         wxCoord label_width;
 221         wxCoord label_height;
 222         wxGraphicsPath lines = gc->CreatePath ();
 223
 224         /* Row channel labels */
 225
 226         int N = 0;
 227         BOOST_FOREACH (string i, _input_channels) {
 228                 dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
 229                 dc.DrawText (std_to_wx(i), GRID_SPACING * 2 + (GRID_SPACING - label_width) / 2, TOP_HEIGHT + GRID_SPACING * N + (GRID_SPACING - label_height) / 2);
 230                 ++N;
 231         }
 232
 233         /* Vertical lines on the left */
 234
 235         for (int i = 1; i < 3; ++i) {
 236                 lines.MoveToPoint    (GRID_SPACING * i, TOP_HEIGHT);
 237                 lines.AddLineToPoint (GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
 238         }
 239
 240         /* Group labels and lines */
 241
 242         int y = TOP_HEIGHT;
 243         BOOST_FOREACH (Group i, _input_groups) {
 244                 int const height = (i.to - i.from + 1) * GRID_SPACING;
 245                 dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
 246                 if (label_width > height) {
 247                         label_width = height - 8;
 248                 }
 249
 250                 {
 251                         int yp = y;
 252                         if ((yp - 2 * GRID_SPACING) < dc.GetLogicalOrigin().y) {
 253                                 yp += dc.GetLogicalOrigin().y;
 254                         }
 255
 256                         wxCoord old_x, old_y, old_width, old_height;
 257                         dc.GetClippingBox (&old_x, &old_y, &old_width, &old_height);
 258                         dc.DestroyClippingRegion ();
 259                         dc.SetClippingRegion (GRID_SPACING, yp + 4, GRID_SPACING, height - 8);
 260
 261                         dc.DrawRotatedText (
 262                                 std_to_wx(i.name),
 263                                 GRID_SPACING + (GRID_SPACING - label_height) / 2,
 264                                 y + (height + label_width) / 2,
 265                                 90
 266                                 );
 267
 268                         dc.DestroyClippingRegion ();
 269                         dc.SetClippingRegion (old_x, old_y, old_width, old_height);
 270                 }
 271
 272                 lines.MoveToPoint    (GRID_SPACING,     y);
 273                 lines.AddLineToPoint (GRID_SPACING * 2, y);
 274                 y += height;
 275         }
 276
 277         lines.MoveToPoint    (GRID_SPACING,     y);
 278         lines.AddLineToPoint (GRID_SPACING * 2, y);
 279
 280         gc->StrokePath (lines);
 281 }
 282
 283 void
 284 AudioMappingView::paint_row_lines (wxGraphicsContext* gc)
 285 {
 286         wxGraphicsPath lines = gc->CreatePath ();
 287         for (size_t i = 0; i < _input_channels.size(); ++i) {
 288                 lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * i);
 289                 lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * i);
 290         }
 291         lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
 292         lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
 293         gc->StrokePath (lines);
 294 }
 295
 296 void
 297 AudioMappingView::paint_indicators (wxDC& dc)
 298 {
 299         /* _{input,output}_channels and _map may not always be in sync, be careful here */
 300         size_t const output = min(_output_channels.size(), size_t(_map.output_channels()));
 301         size_t const input = min(_input_channels.size(), size_t(_map.input_channels()));
 302
 303         for (size_t x = 0; x < output; ++x) {
 304                 for (size_t y = 0; y < input; ++y) {
 305                         dc.SetBrush (*wxWHITE_BRUSH);
 306                         dc.DrawRectangle (
 307                                 wxRect(
 308                                         LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 309                                         TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 310                                         INDICATOR_SIZE, INDICATOR_SIZE
 311                                         )
 312                                 );
 313
 314                         float const value_dB = linear_to_db(_map.get(y, x));
 315                         wxColour const colour = value_dB <= 0 ? wxColour(0, 255, 0) : wxColour(255, 150, 0);
 316                         int const range = 18;
 317                         int height = 0;
 318                         if (value_dB > -range) {
 319                                 height = min(INDICATOR_SIZE, static_cast<int>(INDICATOR_SIZE * (1 + value_dB / range)));
 320                         }
 321
 322                         dc.SetBrush (*wxTheBrushList->FindOrCreateBrush(colour, wxBRUSHSTYLE_SOLID));
 323                         dc.DrawRectangle (
 324                                 wxRect(
 325                                         LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
 326                                         TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2 + INDICATOR_SIZE - height,
 327                                         INDICATOR_SIZE, height
 328                                         )
 329                                 );
 330                 }
 331         }
 332 }
 333
 334 static
 335 void clip (wxDC& dc, wxGraphicsContext* gc, int x, int y, int w, int h)
 336 {
 337         dc.SetClippingRegion (x, y, w, h);
 338         gc->Clip (x, y, w, h);
 339 }
 340
 341 static
 342 void translate (wxDC& dc, wxGraphicsContext* gc, int x, int y)
 343 {
 344         gc->PushState ();
 345         gc->Translate (-x, -y);
 346         dc.SetLogicalOrigin (x, y);
 347 }
 348
 349 static
 350 void restore (wxDC& dc, wxGraphicsContext* gc)
 351 {
 352         dc.SetLogicalOrigin (0, 0);
 353         gc->PopState ();
 354         dc.DestroyClippingRegion ();
 355         gc->ResetClip ();
 356 }
 357
 358 void
 359 AudioMappingView::paint ()
 360 {
 361         wxPaintDC dc (_body);
 362
 363         wxGraphicsContext* gc = wxGraphicsContext::Create (dc);
 364         if (!gc) {
 365                 return;
 366         }
 367
 368         int const hs = _horizontal_scroll->GetThumbPosition ();
 369         int const vs = _vertical_scroll->GetThumbPosition ();
 370
 371         paint_static (dc, gc);
 372
 373         clip (dc, gc, LEFT_WIDTH, 0, GRID_SPACING * _output_channels.size(), GRID_SPACING * (2 + _input_channels.size()));
 374         translate (dc, gc, hs, 0);
 375         paint_column_labels (dc, gc);
 376         restore (dc, gc);
 377
 378         clip (dc, gc, 0, TOP_HEIGHT, GRID_SPACING * (3 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
 379         translate (dc, gc, 0, vs);
 380         paint_row_labels (dc, gc);
 381         restore (dc, gc);
 382
 383         clip (dc, gc, GRID_SPACING * 2, TOP_HEIGHT, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
 384         translate (dc, gc, hs, vs);
 385         paint_row_lines (gc);
 386         restore (dc, gc);
 387
 388         clip (dc, gc, LEFT_WIDTH, GRID_SPACING, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * (1 + _input_channels.size()));
 389         translate (dc, gc, hs, vs);
 390         paint_column_lines (gc);
 391         restore (dc, gc);
 392
 393         clip (dc, gc, LEFT_WIDTH, TOP_HEIGHT, GRID_SPACING * _output_channels.size(), GRID_SPACING * _input_channels.size());
 394         translate (dc, gc, hs, vs);
 395         paint_indicators (dc);
 396         restore (dc, gc);
 397
 398         delete gc;
 399 }
 400
 401 optional<pair<int, int> >
 402 AudioMappingView::mouse_event_to_channels (wxMouseEvent& ev) const
 403 {
 404         int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
 405         int const y = ev.GetY() + _vertical_scroll->GetThumbPosition();
 406
 407         if (x <= LEFT_WIDTH || y < TOP_HEIGHT) {
 408                 return optional<pair<int, int> >();
 409         }
 410
 411         int const input = (y - TOP_HEIGHT) / GRID_SPACING;
 412         int const output = (x - LEFT_WIDTH) / GRID_SPACING;
 413
 414         if (input >= int(_input_channels.size()) || output >= int(_output_channels.size())) {
 415                 return optional<pair<int, int> >();
 416         }
 417
 418         return make_pair (input, output);
 419 }
 420
 421 optional<string>
 422 AudioMappingView::mouse_event_to_input_group_name (wxMouseEvent& ev) const
 423 {
 424         int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
 425         if (x < GRID_SPACING || x > (2 * GRID_SPACING)) {
 426                 return optional<string>();
 427         }
 428
 429         int y = (ev.GetY() + _vertical_scroll->GetThumbPosition() - (GRID_SPACING * 2)) / GRID_SPACING;
 430         BOOST_FOREACH (Group i, _input_groups) {
 431                 if (i.from <= y && y <= i.to) {
 432                         return i.name;
 433                 }
 434         }
 435
 436         return optional<string>();
 437 }
 438
 439 void
 440 AudioMappingView::left_down (wxMouseEvent& ev)
 441 {
 442         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 443         if (!channels) {
 444                 return;
 445         }
 446
 447         if (_map.get(channels->first, channels->second) > 0) {
 448                 _map.set (channels->first, channels->second, 0);
 449         } else {
 450                 _map.set (channels->first, channels->second, 1);
 451         }
 452
 453         map_values_changed ();
 454 }
 455
 456 void
 457 AudioMappingView::right_down (wxMouseEvent& ev)
 458 {
 459         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 460         if (!channels) {
 461                 return;
 462         }
 463
 464         _menu_input = channels->first;
 465         _menu_output = channels->second;
 466         PopupMenu (_menu, ev.GetPosition());
 467 }
 468
 469 void
 470 AudioMappingView::mouse_wheel (wxMouseEvent& ev)
 471 {
 472         if (ev.ShiftDown()) {
 473                 _horizontal_scroll->SetThumbPosition (
 474                         _horizontal_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
 475                         );
 476
 477         } else {
 478                 _vertical_scroll->SetThumbPosition (
 479                         _vertical_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
 480                         );
 481         }
 482         Refresh ();
 483 }
 484
 485 /** Called when any gain value has changed */
 486 void
 487 AudioMappingView::map_values_changed ()
 488 {
 489         Changed (_map);
 490         _last_tooltip_channels = optional<pair<int, int> >();
 491         Refresh ();
 492 }
 493
 494 void
 495 AudioMappingView::set_gain_from_menu (double linear)
 496 {
 497         _map.set (_menu_input, _menu_output, linear);
 498         map_values_changed ();
 499 }
 500
 501 void
 502 AudioMappingView::edit ()
 503 {
 504         AudioGainDialog* dialog = new AudioGainDialog (this, _menu_input, _menu_output, _map.get(_menu_input, _menu_output));
 505         if (dialog->ShowModal() == wxID_OK) {
 506                 _map.set (_menu_input, _menu_output, dialog->value ());
 507                 map_values_changed ();
 508         }
 509
 510         dialog->Destroy ();
 511 }
 512
 513 void
 514 AudioMappingView::set (AudioMapping map)
 515 {
 516         _map = map;
 517         Refresh ();
 518 }
 519
 520 void
 521 AudioMappingView::set_input_channels (vector<string> const & names)
 522 {
 523         _input_channels = names;
 524         setup ();
 525         Refresh ();
 526 }
 527
 528 void
 529 AudioMappingView::set_output_channels (vector<string> const & names)
 530 {
 531         _output_channels = names;
 532         setup ();
 533         Refresh ();
 534 }
 535
 536 wxString
 537 AudioMappingView::safe_input_channel_name (int n) const
 538 {
 539         if (n >= int(_input_channels.size())) {
 540                 return wxString::Format ("%d", n + 1);
 541         }
 542
 543         optional<wxString> group;
 544         BOOST_FOREACH (Group i, _input_groups) {
 545                 if (i.from <= n && n <= i.to) {
 546                         group = std_to_wx (i.name);
 547                 }
 548         }
 549
 550         if (group && !group->IsEmpty()) {
 551                 return wxString::Format ("%s/%s", group->data(), std_to_wx(_input_channels[n]).data());
 552         }
 553
 554         return std_to_wx(_input_channels[n]);
 555 }
 556
 557 wxString
 558 AudioMappingView::safe_output_channel_name (int n) const
 559 {
 560         if (n >= int(_output_channels.size())) {
 561                 return wxString::Format ("%d", n + 1);
 562         }
 563
 564         return std_to_wx(_output_channels[n]);
 565 }
 566
 567 void
 568 AudioMappingView::motion (wxMouseEvent& ev)
 569 {
 570         optional<pair<int, int> > channels = mouse_event_to_channels (ev);
 571         if (channels) {
 572                 if (channels != _last_tooltip_channels) {
 573                         wxString s;
 574                         float const gain = _map.get(channels->first, channels->second);
 575                         if (gain == 0) {
 576                                 s = wxString::Format (
 577                                         _("No audio will be passed from %s channel '%s' to %s channel '%s'."),
 578                                         _from,
 579                                         safe_input_channel_name(channels->first),
 580                                         _to,
 581                                         safe_output_channel_name(channels->second)
 582                                         );
 583                         } else if (gain == 1) {
 584                                 s = wxString::Format (
 585                                         _("Audio will be passed from %s channel %s to %s channel %s unaltered."),
 586                                         _from,
 587                                         safe_input_channel_name(channels->first),
 588                                         _to,
 589                                         safe_output_channel_name(channels->second)
 590                                         );
 591                         } else {
 592                                 float const dB = linear_to_db(gain);
 593                                 s = wxString::Format (
 594                                         _("Audio will be passed from %s channel %s to %s channel %s with gain %.1fdB."),
 595                                         _from,
 596                                         safe_input_channel_name(channels->first),
 597                                         _to,
 598                                         safe_output_channel_name(channels->second),
 599                                         dB
 600                                         );
 601                         }
 602
 603                         SetToolTip (s + " " + _("Right click to change gain."));
 604                 }
 605         } else {
 606                 optional<string> group = mouse_event_to_input_group_name (ev);
 607                 if (group) {
 608                         SetToolTip (std_to_wx(*group));
 609                 } else {
 610                         SetToolTip ("");
 611                 }
 612         }
 613
 614         _last_tooltip_channels = channels;
 615         ev.Skip ();
 616 }
 617
 618 void
 619 AudioMappingView::set_input_groups (vector<Group> const & groups)
 620 {
 621         _input_groups = groups;
 622 }