src/wx/timeline.cc

   1 /*
   2     Copyright (C) 2013 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include <list>
  21 #include <wx/graphics.h>
  22 #include <boost/weak_ptr.hpp>
  23 #include "lib/film.h"
  24 #include "lib/playlist.h"
  25 #include "film_editor.h"
  26 #include "timeline.h"
  27 #include "wx_util.h"
  28
  29 using std::list;
  30 using std::cout;
  31 using std::max;
  32 using boost::shared_ptr;
  33 using boost::weak_ptr;
  34 using boost::dynamic_pointer_cast;
  35 using boost::bind;
  36 using boost::optional;
  37
  38 /** Parent class for components of the timeline (e.g. a piece of content or an axis) */
  39 class View : public boost::noncopyable
  40 {
  41 public:
  42         View (Timeline& t)
  43                 : _timeline (t)
  44         {
  45
  46         }
  47
  48         virtual ~View () {}
  49
  50         void paint (wxGraphicsContext* g)
  51         {
  52                 _last_paint_bbox = bbox ();
  53                 do_paint (g);
  54         }
  55
  56         void force_redraw ()
  57         {
  58                 _timeline.force_redraw (_last_paint_bbox);
  59                 _timeline.force_redraw (bbox ());
  60         }
  61
  62         virtual dcpomatic::Rect<int> bbox () const = 0;
  63
  64 protected:
  65         virtual void do_paint (wxGraphicsContext *) = 0;
  66
  67         int time_x (DCPTime t) const
  68         {
  69                 return _timeline.tracks_position().x + t.seconds() * _timeline.pixels_per_second ();
  70         }
  71
  72         Timeline& _timeline;
  73
  74 private:
  75         dcpomatic::Rect<int> _last_paint_bbox;
  76 };
  77
  78
  79 /** Parent class for views of pieces of content */
  80 class ContentView : public View
  81 {
  82 public:
  83         ContentView (Timeline& tl, shared_ptr<Content> c)
  84                 : View (tl)
  85                 , _content (c)
  86                 , _track (0)
  87                 , _selected (false)
  88         {
  89                 _content_connection = c->Changed.connect (bind (&ContentView::content_changed, this, _2, _3));
  90         }
  91
  92         dcpomatic::Rect<int> bbox () const
  93         {
  94                 shared_ptr<const Film> film = _timeline.film ();
  95                 shared_ptr<const Content> content = _content.lock ();
  96                 if (!film || !content) {
  97                         return dcpomatic::Rect<int> ();
  98                 }
  99
 100                 return dcpomatic::Rect<int> (
 101                         time_x (content->position ()) - 8,
 102                         y_pos (_track) - 8,
 103                         content->length_after_trim().seconds() * _timeline.pixels_per_second() + 16,
 104                         _timeline.track_height() + 16
 105                         );
 106         }
 107
 108         void set_selected (bool s) {
 109                 _selected = s;
 110                 force_redraw ();
 111         }
 112
 113         bool selected () const {
 114                 return _selected;
 115         }
 116
 117         shared_ptr<Content> content () const {
 118                 return _content.lock ();
 119         }
 120
 121         void set_track (int t) {
 122                 _track = t;
 123         }
 124
 125         int track () const {
 126                 return _track;
 127         }
 128
 129         virtual wxString type () const = 0;
 130         virtual wxColour colour () const = 0;
 131
 132 private:
 133
 134         void do_paint (wxGraphicsContext* gc)
 135         {
 136                 shared_ptr<const Film> film = _timeline.film ();
 137                 shared_ptr<const Content> cont = content ();
 138                 if (!film || !cont) {
 139                         return;
 140                 }
 141
 142                 DCPTime const position = cont->position ();
 143                 DCPTime const len = cont->length_after_trim ();
 144
 145                 wxColour selected (colour().Red() / 2, colour().Green() / 2, colour().Blue() / 2);
 146
 147                 gc->SetPen (*wxBLACK_PEN);
 148
 149                 gc->SetPen (*wxThePenList->FindOrCreatePen (wxColour (0, 0, 0), 4, wxPENSTYLE_SOLID));
 150                 if (_selected) {
 151                         gc->SetBrush (*wxTheBrushList->FindOrCreateBrush (selected, wxBRUSHSTYLE_SOLID));
 152                 } else {
 153                         gc->SetBrush (*wxTheBrushList->FindOrCreateBrush (colour(), wxBRUSHSTYLE_SOLID));
 154                 }
 155
 156                 wxGraphicsPath path = gc->CreatePath ();
 157                 path.MoveToPoint    (time_x (position),       y_pos (_track) + 4);
 158                 path.AddLineToPoint (time_x (position + len), y_pos (_track) + 4);
 159                 path.AddLineToPoint (time_x (position + len), y_pos (_track + 1) - 4);
 160                 path.AddLineToPoint (time_x (position),       y_pos (_track + 1) - 4);
 161                 path.AddLineToPoint (time_x (position),       y_pos (_track) + 4);
 162                 gc->StrokePath (path);
 163                 gc->FillPath (path);
 164
 165                 wxString name = wxString::Format (wxT ("%s [%s]"), std_to_wx (cont->path_summary()).data(), type().data());
 166                 wxDouble name_width;
 167                 wxDouble name_height;
 168                 wxDouble name_descent;
 169                 wxDouble name_leading;
 170                 gc->GetTextExtent (name, &name_width, &name_height, &name_descent, &name_leading);
 171
 172                 gc->Clip (wxRegion (time_x (position), y_pos (_track), len.seconds() * _timeline.pixels_per_second(), _timeline.track_height()));
 173                 gc->DrawText (name, time_x (position) + 12, y_pos (_track + 1) - name_height - 4);
 174                 gc->ResetClip ();
 175         }
 176
 177         int y_pos (int t) const
 178         {
 179                 return _timeline.tracks_position().y + t * _timeline.track_height();
 180         }
 181
 182         void content_changed (int p, bool frequent)
 183         {
 184                 ensure_ui_thread ();
 185
 186                 if (p == ContentProperty::POSITION || p == ContentProperty::LENGTH) {
 187                         force_redraw ();
 188                 }
 189
 190                 if (!frequent) {
 191                         _timeline.setup_pixels_per_second ();
 192                         _timeline.Refresh ();
 193                 }
 194         }
 195
 196         boost::weak_ptr<Content> _content;
 197         int _track;
 198         bool _selected;
 199
 200         boost::signals2::scoped_connection _content_connection;
 201 };
 202
 203 class AudioContentView : public ContentView
 204 {
 205 public:
 206         AudioContentView (Timeline& tl, shared_ptr<Content> c)
 207                 : ContentView (tl, c)
 208         {}
 209
 210 private:
 211         wxString type () const
 212         {
 213                 return _("audio");
 214         }
 215
 216         wxColour colour () const
 217         {
 218                 return wxColour (149, 121, 232, 255);
 219         }
 220 };
 221
 222 class VideoContentView : public ContentView
 223 {
 224 public:
 225         VideoContentView (Timeline& tl, shared_ptr<Content> c)
 226                 : ContentView (tl, c)
 227         {}
 228
 229 private:
 230
 231         wxString type () const
 232         {
 233                 if (dynamic_pointer_cast<FFmpegContent> (content ())) {
 234                         return _("video");
 235                 } else {
 236                         return _("still");
 237                 }
 238         }
 239
 240         wxColour colour () const
 241         {
 242                 return wxColour (242, 92, 120, 255);
 243         }
 244 };
 245
 246 class SubtitleContentView : public ContentView
 247 {
 248 public:
 249         SubtitleContentView (Timeline& tl, shared_ptr<Content> c)
 250                 : ContentView (tl, c)
 251         {}
 252
 253 private:
 254         wxString type () const
 255         {
 256                 return _("subtitles");
 257         }
 258
 259         wxColour colour () const
 260         {
 261                 return wxColour (163, 255, 154, 255);
 262         }
 263 };
 264
 265 class TimeAxisView : public View
 266 {
 267 public:
 268         TimeAxisView (Timeline& tl, int y)
 269                 : View (tl)
 270                 , _y (y)
 271         {}
 272
 273         dcpomatic::Rect<int> bbox () const
 274         {
 275                 return dcpomatic::Rect<int> (0, _y - 4, _timeline.width(), 24);
 276         }
 277
 278         void set_y (int y)
 279         {
 280                 _y = y;
 281                 force_redraw ();
 282         }
 283
 284 private:
 285
 286         void do_paint (wxGraphicsContext* gc)
 287         {
 288                 gc->SetPen (*wxThePenList->FindOrCreatePen (wxColour (0, 0, 0), 1, wxPENSTYLE_SOLID));
 289
 290                 double mark_interval = rint (128 / _timeline.pixels_per_second ());
 291                 if (mark_interval > 5) {
 292                         mark_interval -= int (rint (mark_interval)) % 5;
 293                 }
 294                 if (mark_interval > 10) {
 295                         mark_interval -= int (rint (mark_interval)) % 10;
 296                 }
 297                 if (mark_interval > 60) {
 298                         mark_interval -= int (rint (mark_interval)) % 60;
 299                 }
 300                 if (mark_interval > 3600) {
 301                         mark_interval -= int (rint (mark_interval)) % 3600;
 302                 }
 303
 304                 if (mark_interval < 1) {
 305                         mark_interval = 1;
 306                 }
 307
 308                 wxGraphicsPath path = gc->CreatePath ();
 309                 path.MoveToPoint (_timeline.x_offset(), _y);
 310                 path.AddLineToPoint (_timeline.width(), _y);
 311                 gc->StrokePath (path);
 312
 313                 /* Time in seconds */
 314                 DCPTime t;
 315                 while ((t.seconds() * _timeline.pixels_per_second()) < _timeline.width()) {
 316                         wxGraphicsPath path = gc->CreatePath ();
 317                         path.MoveToPoint (time_x (t), _y - 4);
 318                         path.AddLineToPoint (time_x (t), _y + 4);
 319                         gc->StrokePath (path);
 320
 321                         double tc = t.seconds ();
 322                         int const h = tc / 3600;
 323                         tc -= h * 3600;
 324                         int const m = tc / 60;
 325                         tc -= m * 60;
 326                         int const s = tc;
 327
 328                         wxString str = wxString::Format (wxT ("%02d:%02d:%02d"), h, m, s);
 329                         wxDouble str_width;
 330                         wxDouble str_height;
 331                         wxDouble str_descent;
 332                         wxDouble str_leading;
 333                         gc->GetTextExtent (str, &str_width, &str_height, &str_descent, &str_leading);
 334
 335                         int const tx = _timeline.x_offset() + t.seconds() * _timeline.pixels_per_second();
 336                         if ((tx + str_width) < _timeline.width()) {
 337                                 gc->DrawText (str, time_x (t), _y + 16);
 338                         }
 339
 340                         t += DCPTime::from_seconds (mark_interval);
 341                 }
 342         }
 343
 344 private:
 345         int _y;
 346 };
 347
 348
 349 Timeline::Timeline (wxWindow* parent, FilmEditor* ed, shared_ptr<Film> film)
 350         : wxPanel (parent, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxFULL_REPAINT_ON_RESIZE)
 351         , _film_editor (ed)
 352         , _film (film)
 353         , _time_axis_view (new TimeAxisView (*this, 32))
 354         , _tracks (0)
 355         , _pixels_per_second (0)
 356         , _left_down (false)
 357         , _down_view_position (0)
 358         , _first_move (false)
 359         , _menu (this)
 360         , _snap (true)
 361 {
 362 #ifndef __WXOSX__
 363         SetDoubleBuffered (true);
 364 #endif
 365
 366         Bind (wxEVT_PAINT,      boost::bind (&Timeline::paint,       this));
 367         Bind (wxEVT_LEFT_DOWN,  boost::bind (&Timeline::left_down,   this, _1));
 368         Bind (wxEVT_LEFT_UP,    boost::bind (&Timeline::left_up,     this, _1));
 369         Bind (wxEVT_RIGHT_DOWN, boost::bind (&Timeline::right_down,  this, _1));
 370         Bind (wxEVT_MOTION,     boost::bind (&Timeline::mouse_moved, this, _1));
 371         Bind (wxEVT_SIZE,       boost::bind (&Timeline::resized,     this));
 372
 373         playlist_changed ();
 374
 375         SetMinSize (wxSize (640, tracks() * track_height() + 96));
 376
 377         _playlist_connection = film->playlist()->Changed.connect (bind (&Timeline::playlist_changed, this));
 378 }
 379
 380 void
 381 Timeline::paint ()
 382 {
 383         wxPaintDC dc (this);
 384
 385         wxGraphicsContext* gc = wxGraphicsContext::Create (dc);
 386         if (!gc) {
 387                 return;
 388         }
 389
 390         gc->SetFont (gc->CreateFont (*wxNORMAL_FONT));
 391
 392         for (ViewList::iterator i = _views.begin(); i != _views.end(); ++i) {
 393                 (*i)->paint (gc);
 394         }
 395
 396         delete gc;
 397 }
 398
 399 void
 400 Timeline::playlist_changed ()
 401 {
 402         ensure_ui_thread ();
 403
 404         shared_ptr<const Film> fl = _film.lock ();
 405         if (!fl) {
 406                 return;
 407         }
 408
 409         _views.clear ();
 410         _views.push_back (_time_axis_view);
 411
 412         ContentList content = fl->playlist()->content ();
 413
 414         for (ContentList::iterator i = content.begin(); i != content.end(); ++i) {
 415                 if (dynamic_pointer_cast<VideoContent> (*i)) {
 416                         _views.push_back (shared_ptr<View> (new VideoContentView (*this, *i)));
 417                 }
 418                 if (dynamic_pointer_cast<AudioContent> (*i)) {
 419                         _views.push_back (shared_ptr<View> (new AudioContentView (*this, *i)));
 420                 }
 421                 if (dynamic_pointer_cast<SubtitleContent> (*i)) {
 422                         _views.push_back (shared_ptr<View> (new SubtitleContentView (*this, *i)));
 423                 }
 424         }
 425
 426         assign_tracks ();
 427         setup_pixels_per_second ();
 428         Refresh ();
 429 }
 430
 431 void
 432 Timeline::assign_tracks ()
 433 {
 434         list<shared_ptr<VideoContentView> > video;
 435         list<shared_ptr<AudioContentView> > audio;
 436         list<shared_ptr<SubtitleContentView> > subtitle;
 437
 438         for (ViewList::iterator i = _views.begin(); i != _views.end(); ++i) {
 439                 shared_ptr<VideoContentView> v = dynamic_pointer_cast<VideoContentView> (*i);
 440                 if (v) {
 441                         video.push_back (v);
 442                 }
 443
 444                 shared_ptr<AudioContentView> a = dynamic_pointer_cast<AudioContentView> (*i);
 445                 if (a) {
 446                         audio.push_back (a);
 447                 }
 448
 449                 shared_ptr<SubtitleContentView> s = dynamic_pointer_cast<SubtitleContentView> (*i);
 450                 if (s) {
 451                         subtitle.push_back (s);
 452                 }
 453         }
 454
 455         _tracks = 0;
 456         if (!video.empty ()) {
 457                 for (list<shared_ptr<VideoContentView> >::iterator i = video.begin(); i != video.end(); ++i) {
 458                         (*i)->set_track (_tracks);
 459                 }
 460                 ++_tracks;
 461         }
 462
 463         if (!subtitle.empty ()) {
 464                 for (list<shared_ptr<SubtitleContentView> >::iterator i = subtitle.begin(); i != subtitle.end(); ++i) {
 465                         (*i)->set_track (_tracks);
 466                 }
 467                 ++_tracks;
 468         }
 469
 470         int const audio_start = _tracks;
 471
 472         for (list<shared_ptr<AudioContentView> >::iterator i = audio.begin(); i != audio.end(); ++i) {
 473                 shared_ptr<Content> acv_content = (*i)->content();
 474
 475                 int t = audio_start;
 476                 while (1) {
 477                         list<shared_ptr<AudioContentView> >::iterator j = audio.begin ();
 478                         while (j != audio.end()) {
 479                                 if ((*j)->track() == t) {
 480                                         bool const no_overlap =
 481                                                 (acv_content->position() < (*j)->content()->position() && acv_content->end() < (*j)->content()->position()) ||
 482                                                 (acv_content->position() > (*j)->content()->end()      && acv_content->end() > (*j)->content()->end());
 483
 484                                         if (!no_overlap) {
 485                                                 /* we have an overlap on track `t' */
 486                                                 ++t;
 487                                                 break;
 488                                         }
 489                                 }
 490
 491                                 ++j;
 492                         }
 493
 494                         if (j == audio.end ()) {
 495                                 /* no overlap on `t' */
 496                                 break;
 497                         }
 498                 }
 499
 500                 (*i)->set_track (t);
 501                 _tracks = max (_tracks, t + 1);
 502         }
 503
 504         _time_axis_view->set_y (tracks() * track_height() + 32);
 505 }
 506
 507 int
 508 Timeline::tracks () const
 509 {
 510         return _tracks;
 511 }
 512
 513 void
 514 Timeline::setup_pixels_per_second ()
 515 {
 516         shared_ptr<const Film> film = _film.lock ();
 517         if (!film || film->length() == DCPTime ()) {
 518                 return;
 519         }
 520
 521         _pixels_per_second = static_cast<double>(width() - x_offset() * 2) / film->length().seconds ();
 522 }
 523
 524 shared_ptr<View>
 525 Timeline::event_to_view (wxMouseEvent& ev)
 526 {
 527         ViewList::iterator i = _views.begin();
 528         Position<int> const p (ev.GetX(), ev.GetY());
 529         while (i != _views.end() && !(*i)->bbox().contains (p)) {
 530                 ++i;
 531         }
 532
 533         if (i == _views.end ()) {
 534                 return shared_ptr<View> ();
 535         }
 536
 537         return *i;
 538 }
 539
 540 void
 541 Timeline::left_down (wxMouseEvent& ev)
 542 {
 543         shared_ptr<View> view = event_to_view (ev);
 544         shared_ptr<ContentView> content_view = dynamic_pointer_cast<ContentView> (view);
 545
 546         _down_view.reset ();
 547
 548         if (content_view) {
 549                 _down_view = content_view;
 550                 _down_view_position = content_view->content()->position ();
 551         }
 552
 553         for (ViewList::iterator i = _views.begin(); i != _views.end(); ++i) {
 554                 shared_ptr<ContentView> cv = dynamic_pointer_cast<ContentView> (*i);
 555                 if (!cv) {
 556                         continue;
 557                 }
 558
 559                 if (!ev.ShiftDown ()) {
 560                         cv->set_selected (view == *i);
 561                 }
 562
 563                 if (view == *i) {
 564                         _film_editor->set_selection (cv->content ());
 565                 }
 566         }
 567
 568         if (content_view && ev.ShiftDown ()) {
 569                 content_view->set_selected (!content_view->selected ());
 570         }
 571
 572         _left_down = true;
 573         _down_point = ev.GetPosition ();
 574         _first_move = false;
 575
 576         if (_down_view) {
 577                 _down_view->content()->set_change_signals_frequent (true);
 578         }
 579 }
 580
 581 void
 582 Timeline::left_up (wxMouseEvent& ev)
 583 {
 584         _left_down = false;
 585
 586         if (_down_view) {
 587                 _down_view->content()->set_change_signals_frequent (false);
 588         }
 589
 590         set_position_from_event (ev);
 591 }
 592
 593 void
 594 Timeline::mouse_moved (wxMouseEvent& ev)
 595 {
 596         if (!_left_down) {
 597                 return;
 598         }
 599
 600         set_position_from_event (ev);
 601 }
 602
 603 void
 604 Timeline::right_down (wxMouseEvent& ev)
 605 {
 606         shared_ptr<View> view = event_to_view (ev);
 607         shared_ptr<ContentView> cv = dynamic_pointer_cast<ContentView> (view);
 608         if (!cv) {
 609                 return;
 610         }
 611
 612         if (!cv->selected ()) {
 613                 clear_selection ();
 614                 cv->set_selected (true);
 615         }
 616
 617         _menu.popup (_film, selected_content (), ev.GetPosition ());
 618 }
 619
 620 void
 621 Timeline::set_position_from_event (wxMouseEvent& ev)
 622 {
 623         wxPoint const p = ev.GetPosition();
 624
 625         if (!_first_move) {
 626                 /* We haven't moved yet; in that case, we must move the mouse some reasonable distance
 627                    before the drag is considered to have started.
 628                 */
 629                 int const dist = sqrt (pow (p.x - _down_point.x, 2) + pow (p.y - _down_point.y, 2));
 630                 if (dist < 8) {
 631                         return;
 632                 }
 633                 _first_move = true;
 634         }
 635
 636         if (!_down_view) {
 637                 return;
 638         }
 639
 640         DCPTime new_position = _down_view_position + DCPTime::from_seconds ((p.x - _down_point.x) / _pixels_per_second);
 641
 642         if (_snap) {
 643
 644                 bool first = true;
 645                 DCPTime nearest_distance = DCPTime::max ();
 646                 DCPTime nearest_new_position = DCPTime::max ();
 647
 648                 /* Find the nearest content edge; this is inefficient */
 649                 for (ViewList::iterator i = _views.begin(); i != _views.end(); ++i) {
 650                         shared_ptr<ContentView> cv = dynamic_pointer_cast<ContentView> (*i);
 651                         if (!cv || cv == _down_view) {
 652                                 continue;
 653                         }
 654
 655                         {
 656                                 /* Snap starts to ends */
 657                                 DCPTime const d = DCPTime (cv->content()->end() - new_position).abs ();
 658                                 if (first || d < nearest_distance) {
 659                                         nearest_distance = d;
 660                                         nearest_new_position = cv->content()->end();
 661                                 }
 662                         }
 663
 664                         {
 665                                 /* Snap ends to starts */
 666                                 DCPTime const d = DCPTime (
 667                                         cv->content()->position() - (new_position + _down_view->content()->length_after_trim())
 668                                         ).abs ();
 669
 670                                 if (d < nearest_distance) {
 671                                         nearest_distance = d;
 672                                         nearest_new_position = cv->content()->position() - _down_view->content()->length_after_trim ();
 673                                 }
 674                         }
 675
 676                         first = false;
 677                 }
 678
 679                 if (!first) {
 680                         /* Snap if it's close; `close' means within a proportion of the time on the timeline */
 681                         if (nearest_distance < DCPTime::from_seconds ((width() / pixels_per_second()) / 32)) {
 682                                 new_position = nearest_new_position;
 683                         }
 684                 }
 685         }
 686
 687         if (new_position < DCPTime ()) {
 688                 new_position = DCPTime ();
 689         }
 690
 691         _down_view->content()->set_position (new_position);
 692
 693         shared_ptr<Film> film = _film.lock ();
 694         assert (film);
 695         film->set_sequence_video (false);
 696 }
 697
 698 void
 699 Timeline::force_redraw (dcpomatic::Rect<int> const & r)
 700 {
 701         RefreshRect (wxRect (r.x, r.y, r.width, r.height), false);
 702 }
 703
 704 shared_ptr<const Film>
 705 Timeline::film () const
 706 {
 707         return _film.lock ();
 708 }
 709
 710 void
 711 Timeline::resized ()
 712 {
 713         setup_pixels_per_second ();
 714 }
 715
 716 void
 717 Timeline::clear_selection ()
 718 {
 719         for (ViewList::iterator i = _views.begin(); i != _views.end(); ++i) {
 720                 shared_ptr<ContentView> cv = dynamic_pointer_cast<ContentView> (*i);
 721                 if (cv) {
 722                         cv->set_selected (false);
 723                 }
 724         }
 725 }
 726
 727 Timeline::ContentViewList
 728 Timeline::selected_views () const
 729 {
 730         ContentViewList sel;
 731
 732         for (ViewList::const_iterator i = _views.begin(); i != _views.end(); ++i) {
 733                 shared_ptr<ContentView> cv = dynamic_pointer_cast<ContentView> (*i);
 734                 if (cv && cv->selected()) {
 735                         sel.push_back (cv);
 736                 }
 737         }
 738
 739         return sel;
 740 }
 741
 742 ContentList
 743 Timeline::selected_content () const
 744 {
 745         ContentList sel;
 746         ContentViewList views = selected_views ();
 747
 748         for (ContentViewList::const_iterator i = views.begin(); i != views.end(); ++i) {
 749                 sel.push_back ((*i)->content ());
 750         }
 751
 752         return sel;
 753 }