git.sesse.net Git - nageru/blob - mainwindow.cpp

   1 #include "mainwindow.h"
   2
   3 #include "clip_list.h"
   4 #include "player.h"
   5 #include "post_to_main_thread.h"
   6 #include "timebase.h"
   7 #include "ui_mainwindow.h"
   8
   9 #include <string>
  10 #include <vector>
  11
  12 #include <QMouseEvent>
  13 #include <QWheelEvent>
  14 #include <QShortcut>
  15 #include <QTimer>
  16
  17 #include <sqlite3.h>
  18
  19 using namespace std;
  20
  21 MainWindow *global_mainwindow = nullptr;
  22 ClipList *cliplist_clips;
  23 PlayList *playlist_clips;
  24
  25 extern int64_t current_pts;
  26 extern mutex frame_mu;
  27 extern vector<int64_t> frames[MAX_STREAMS];
  28
  29 MainWindow::MainWindow()
  30         : ui(new Ui::MainWindow),
  31           db("futatabi.db")
  32 {
  33         global_mainwindow = this;
  34         ui->setupUi(this);
  35
  36         StateProto state = db.get_state();
  37
  38         cliplist_clips = new ClipList(state.clip_list());
  39         ui->clip_list->setModel(cliplist_clips);
  40         connect(cliplist_clips, &ClipList::any_content_changed, this, &MainWindow::content_changed);
  41
  42         playlist_clips = new PlayList(state.play_list());
  43         ui->playlist->setModel(playlist_clips);
  44         connect(playlist_clips, &PlayList::any_content_changed, this, &MainWindow::content_changed);
  45
  46         // For scrubbing in the pts columns.
  47         ui->clip_list->viewport()->installEventFilter(this);
  48         ui->playlist->viewport()->installEventFilter(this);
  49
  50         QShortcut *cue_in = new QShortcut(QKeySequence(Qt::Key_A), this);
  51         connect(cue_in, &QShortcut::activated, ui->cue_in_btn, &QPushButton::click);
  52         connect(ui->cue_in_btn, &QPushButton::clicked, this, &MainWindow::cue_in_clicked);
  53
  54         QShortcut *cue_out = new QShortcut(QKeySequence(Qt::Key_S), this);
  55         connect(cue_out, &QShortcut::activated, ui->cue_out_btn, &QPushButton::click);
  56         connect(ui->cue_out_btn, &QPushButton::clicked, this, &MainWindow::cue_out_clicked);
  57
  58         QShortcut *queue = new QShortcut(QKeySequence(Qt::Key_Q), this);
  59         connect(queue, &QShortcut::activated, ui->queue_btn, &QPushButton::click);
  60         connect(ui->queue_btn, &QPushButton::clicked, this, &MainWindow::queue_clicked);
  61
  62         QShortcut *preview = new QShortcut(QKeySequence(Qt::Key_W), this);
  63         connect(preview, &QShortcut::activated, ui->preview_btn, &QPushButton::click);
  64         connect(ui->preview_btn, &QPushButton::clicked, this, &MainWindow::preview_clicked);
  65
  66         QShortcut *play = new QShortcut(QKeySequence(Qt::Key_Space), this);
  67         connect(play, &QShortcut::activated, ui->play_btn, &QPushButton::click);
  68         connect(ui->play_btn, &QPushButton::clicked, this, &MainWindow::play_clicked);
  69
  70         QShortcut *preview_1 = new QShortcut(QKeySequence(Qt::Key_1), this);
  71         connect(preview_1, &QShortcut::activated, ui->preview_1_btn, &QPushButton::click);
  72         connect(ui->input1_display, &JPEGFrameView::clicked, ui->preview_1_btn, &QPushButton::click);
  73         connect(ui->preview_1_btn, &QPushButton::clicked, [this]{ preview_angle_clicked(0); });
  74         ui->input1_display->set_overlay("1");
  75
  76         QShortcut *preview_2 = new QShortcut(QKeySequence(Qt::Key_2), this);
  77         connect(preview_2, &QShortcut::activated, ui->preview_2_btn, &QPushButton::click);
  78         connect(ui->input2_display, &JPEGFrameView::clicked, ui->preview_2_btn, &QPushButton::click);
  79         connect(ui->preview_2_btn, &QPushButton::clicked, [this]{ preview_angle_clicked(1); });
  80         ui->input2_display->set_overlay("2");
  81
  82         QShortcut *preview_3 = new QShortcut(QKeySequence(Qt::Key_3), this);
  83         connect(preview_3, &QShortcut::activated, ui->preview_3_btn, &QPushButton::click);
  84         connect(ui->input3_display, &JPEGFrameView::clicked, ui->preview_3_btn, &QPushButton::click);
  85         connect(ui->preview_3_btn, &QPushButton::clicked, [this]{ preview_angle_clicked(2); });
  86         ui->input3_display->set_overlay("3");
  87
  88         QShortcut *preview_4 = new QShortcut(QKeySequence(Qt::Key_4), this);
  89         connect(preview_4, &QShortcut::activated, ui->preview_4_btn, &QPushButton::click);
  90         connect(ui->input4_display, &JPEGFrameView::clicked, ui->preview_4_btn, &QPushButton::click);
  91         connect(ui->preview_4_btn, &QPushButton::clicked, [this]{ preview_angle_clicked(3); });
  92         ui->input4_display->set_overlay("4");
  93
  94         connect(ui->playlist_duplicate_btn, &QPushButton::clicked, this, &MainWindow::playlist_duplicate);
  95
  96         connect(ui->playlist_remove_btn, &QPushButton::clicked, this, &MainWindow::playlist_remove);
  97         QShortcut *delete_key = new QShortcut(QKeySequence(Qt::Key_Delete), ui->playlist);
  98         connect(delete_key, &QShortcut::activated, [this] {
  99                 if (ui->playlist->hasFocus()) {
 100                         playlist_remove();
 101                 }
 102         });
 103
 104         // TODO: support drag-and-drop.
 105         connect(ui->playlist_move_up_btn, &QPushButton::clicked, [this]{ playlist_move(-1); });
 106         connect(ui->playlist_move_down_btn, &QPushButton::clicked, [this]{ playlist_move(1); });
 107
 108         connect(ui->playlist->selectionModel(), &QItemSelectionModel::selectionChanged,
 109                 this, &MainWindow::playlist_selection_changed);
 110         playlist_selection_changed();  // First time set-up.
 111
 112         preview_player = new Player(ui->preview_display, /*also_output_to_stream=*/false);
 113         live_player = new Player(ui->live_display, /*also_output_to_stream=*/true);
 114         live_player->set_done_callback([this]{
 115                 post_to_main_thread([this]{
 116                         live_player_clip_done();
 117                 });
 118         });
 119         live_player->set_progress_callback([this](double played_this_clip, double total_length) {
 120                 post_to_main_thread([this, played_this_clip, total_length] {
 121                         live_player_clip_progress(played_this_clip, total_length);
 122                 });
 123         });
 124
 125         defer_timeout = new QTimer(this);
 126         defer_timeout->setSingleShot(true);
 127         connect(defer_timeout, &QTimer::timeout, this, &MainWindow::defer_timer_expired);
 128 }
 129
 130 void MainWindow::cue_in_clicked()
 131 {
 132         if (!cliplist_clips->empty() && cliplist_clips->back()->pts_out < 0) {
 133                 cliplist_clips->mutable_back()->pts_in = current_pts;
 134                 return;
 135         }
 136         Clip clip;
 137         clip.pts_in = current_pts;
 138         cliplist_clips->add_clip(clip);
 139         playlist_selection_changed();
 140 }
 141
 142 void MainWindow::cue_out_clicked()
 143 {
 144         if (!cliplist_clips->empty()) {
 145                 cliplist_clips->mutable_back()->pts_out = current_pts;
 146                 // TODO: select the row in the clip list?
 147         }
 148 }
 149
 150 void MainWindow::queue_clicked()
 151 {
 152         if (cliplist_clips->empty()) {
 153                 return;
 154         }
 155
 156         QItemSelectionModel *selected = ui->clip_list->selectionModel();
 157         if (!selected->hasSelection()) {
 158                 Clip clip = *cliplist_clips->back();
 159                 clip.stream_idx = 0;
 160                 if (clip.pts_out != -1) {
 161                         playlist_clips->add_clip(clip);
 162                         playlist_selection_changed();
 163                 }
 164                 return;
 165         }
 166
 167         QModelIndex index = selected->currentIndex();
 168         Clip clip = *cliplist_clips->clip(index.row());
 169         if (index.column() >= int(ClipList::Column::CAMERA_1) &&
 170             index.column() <= int(ClipList::Column::CAMERA_4)) {
 171                 clip.stream_idx = index.column() - int(ClipList::Column::CAMERA_1);
 172         } else {
 173                 clip.stream_idx = ui->preview_display->get_stream_idx();
 174         }
 175
 176         if (clip.pts_out != -1) {
 177                 playlist_clips->add_clip(clip);
 178                 playlist_selection_changed();
 179         }
 180 }
 181
 182 void MainWindow::preview_clicked()
 183 {
 184         if (cliplist_clips->empty()) return;
 185
 186         QItemSelectionModel *selected = ui->clip_list->selectionModel();
 187         if (!selected->hasSelection()) {
 188                 preview_player->play_clip(*cliplist_clips->back(), 0);
 189                 return;
 190         }
 191
 192         QModelIndex index = selected->currentIndex();
 193         unsigned stream_idx;
 194         if (index.column() >= int(ClipList::Column::CAMERA_1) &&
 195             index.column() <= int(ClipList::Column::CAMERA_4)) {
 196                 stream_idx = index.column() - int(ClipList::Column::CAMERA_1);
 197         } else {
 198                 stream_idx = ui->preview_display->get_stream_idx();
 199         }
 200         preview_player->play_clip(*cliplist_clips->clip(index.row()), stream_idx);
 201 }
 202
 203 void MainWindow::preview_angle_clicked(unsigned stream_idx)
 204 {
 205         preview_player->override_angle(stream_idx);
 206
 207         // Change the selection if we were previewing a clip from the clip list.
 208         // (The only other thing we could be showing is a pts scrub, and if so,
 209         // that would be selected.)
 210         QItemSelectionModel *selected = ui->clip_list->selectionModel();
 211         if (selected->hasSelection()) {
 212                 QModelIndex cell = selected->selectedIndexes()[0];
 213                 int column = int(ClipList::Column::CAMERA_1) + stream_idx;
 214                 selected->setCurrentIndex(cell.sibling(cell.row(), column), QItemSelectionModel::ClearAndSelect);
 215         }
 216 }
 217
 218 void MainWindow::playlist_duplicate()
 219 {
 220         QItemSelectionModel *selected = ui->playlist->selectionModel();
 221         if (!selected->hasSelection()) {
 222                 // Should have been grayed out, but OK.
 223                 return;
 224         }
 225         QModelIndexList rows = selected->selectedRows();
 226         int first = rows.front().row(), last = rows.back().row();
 227         playlist_clips->duplicate_clips(first, last);
 228         playlist_selection_changed();
 229 }
 230
 231 void MainWindow::playlist_remove()
 232 {
 233         QItemSelectionModel *selected = ui->playlist->selectionModel();
 234         if (!selected->hasSelection()) {
 235                 // Should have been grayed out, but OK.
 236                 return;
 237         }
 238         QModelIndexList rows = selected->selectedRows();
 239         int first = rows.front().row(), last = rows.back().row();
 240         playlist_clips->erase_clips(first, last);
 241
 242         // TODO: select the next one in the list?
 243
 244         playlist_selection_changed();
 245 }
 246
 247 void MainWindow::playlist_move(int delta)
 248 {
 249         QItemSelectionModel *selected = ui->playlist->selectionModel();
 250         if (!selected->hasSelection()) {
 251                 // Should have been grayed out, but OK.
 252                 return;
 253         }
 254
 255         QModelIndexList rows = selected->selectedRows();
 256         int first = rows.front().row(), last = rows.back().row();
 257         if ((delta == -1 && first == 0) ||
 258             (delta == 1 && size_t(last) == playlist_clips->size() - 1)) {
 259                 // Should have been grayed out, but OK.
 260                 return;
 261         }
 262
 263         playlist_clips->move_clips(first, last, delta);
 264         playlist_selection_changed();
 265 }
 266
 267 void MainWindow::defer_timer_expired()
 268 {
 269         state_changed(deferred_state);
 270 }
 271
 272 void MainWindow::content_changed()
 273 {
 274         if (defer_timeout->isActive() &&
 275             (!currently_deferring_model_changes || deferred_change_id != current_change_id)) {
 276                 // There's some deferred event waiting, but this event is unrelated.
 277                 // So it's time to short-circuit that timer and do the work it wanted to do.
 278                 defer_timeout->stop();
 279                 state_changed(deferred_state);
 280         }
 281         StateProto state;
 282         *state.mutable_clip_list() = cliplist_clips->serialize();
 283         *state.mutable_play_list() = playlist_clips->serialize();
 284         if (currently_deferring_model_changes) {
 285                 deferred_change_id = current_change_id;
 286                 deferred_state = std::move(state);
 287                 defer_timeout->start(200);
 288                 return;
 289         }
 290         state_changed(state);
 291 }
 292
 293 void MainWindow::state_changed(const StateProto &state)
 294 {
 295         db.store_state(state);
 296 }
 297
 298 void MainWindow::play_clicked()
 299 {
 300         if (playlist_clips->empty()) return;
 301
 302         QItemSelectionModel *selected = ui->playlist->selectionModel();
 303         int row;
 304         if (!selected->hasSelection()) {
 305                 row = 0;
 306         } else {
 307                 row = selected->selectedRows(0)[0].row();
 308         }
 309
 310         const Clip &clip = *playlist_clips->clip(row);
 311         live_player->play_clip(clip, clip.stream_idx);
 312         playlist_clips->set_currently_playing(row, 0.0f);
 313         playlist_selection_changed();
 314 }
 315
 316 void MainWindow::live_player_clip_done()
 317 {
 318         int row = playlist_clips->get_currently_playing();
 319         if (row != -1 && row < int(playlist_clips->size()) - 1) {
 320                 ++row;
 321                 const Clip &clip = *playlist_clips->clip(row);
 322                 live_player->play_clip(clip, clip.stream_idx);
 323                 playlist_clips->set_currently_playing(row, 0.0f);
 324         } else {
 325                 playlist_clips->set_currently_playing(-1, 0.0f);
 326                 ui->live_label->setText("Current output (paused)");
 327         }
 328 }
 329
 330 void MainWindow::live_player_clip_progress(double played_this_clip, double total_length)
 331 {
 332         playlist_clips->set_currently_playing(playlist_clips->get_currently_playing(), played_this_clip / total_length);
 333
 334         double remaining = total_length - played_this_clip;
 335         for (int row = playlist_clips->get_currently_playing() + 1; row < int(playlist_clips->size()); ++row) {
 336                 const Clip clip = *playlist_clips->clip(row);
 337                 remaining += double(clip.pts_out - clip.pts_in) / TIMEBASE / 0.5;   // FIXME: stop hardcoding speed.
 338         }
 339         int remaining_ms = lrint(remaining * 1e3);
 340
 341         int ms = remaining_ms % 1000;
 342         remaining_ms /= 1000;
 343         int s = remaining_ms % 60;
 344         remaining_ms /= 60;
 345         int m = remaining_ms;
 346
 347         char buf[256];
 348         snprintf(buf, sizeof(buf), "Current output (%d:%02d.%03d left)", m, s, ms);
 349         ui->live_label->setText(buf);
 350 }
 351
 352 void MainWindow::resizeEvent(QResizeEvent *event)
 353 {
 354         QMainWindow::resizeEvent(event);
 355
 356         // Ask for a relayout, but only after the event loop is done doing relayout
 357         // on everything else.
 358         QMetaObject::invokeMethod(this, "relayout", Qt::QueuedConnection);
 359 }
 360
 361 void MainWindow::relayout()
 362 {
 363         ui->live_display->setMinimumWidth(ui->live_display->height() * 16 / 9);
 364         ui->preview_display->setMinimumWidth(ui->preview_display->height() * 16 / 9);
 365 }
 366
 367 void set_pts_in(int64_t pts, int64_t current_pts, ClipProxy &clip)
 368 {
 369         pts = std::max<int64_t>(pts, 0);
 370         if (clip->pts_out == -1) {
 371                 pts = std::min(pts, current_pts);
 372         } else {
 373                 pts = std::min(pts, clip->pts_out);
 374         }
 375         clip->pts_in = pts;
 376 }
 377
 378 bool MainWindow::eventFilter(QObject *watched, QEvent *event)
 379 {
 380         constexpr int dead_zone_pixels = 3;  // To avoid that simple clicks get misinterpreted.
 381         constexpr int scrub_sensitivity = 100;  // pts units per pixel.
 382         constexpr int wheel_sensitivity = 100;  // pts units per degree.
 383         constexpr int camera_degrees_per_pixel = 15;  // One click of most mice.
 384
 385         unsigned stream_idx = ui->preview_display->get_stream_idx();
 386
 387         if (event->type() != QEvent::Wheel) {
 388                 last_mousewheel_camera_row = -1;
 389         }
 390
 391         if (event->type() == QEvent::MouseButtonPress) {
 392                 QMouseEvent *mouse = (QMouseEvent *)event;
 393
 394                 QTableView *destination;
 395                 ScrubType type;
 396
 397                 if (watched == ui->clip_list->viewport()) {
 398                         destination = ui->clip_list;
 399                         type = SCRUBBING_CLIP_LIST;
 400                 } else if (watched == ui->playlist->viewport()) {
 401                         destination = ui->playlist;
 402                         type = SCRUBBING_PLAYLIST;
 403                 } else {
 404                         return false;
 405                 }
 406                 int column = destination->columnAt(mouse->x());
 407                 int row = destination->rowAt(mouse->y());
 408                 if (column == -1 || row == -1) return false;
 409
 410                 if (type == SCRUBBING_CLIP_LIST) {
 411                         if (ClipList::Column(column) == ClipList::Column::IN) {
 412                                 scrub_pts_origin = cliplist_clips->clip(row)->pts_in;
 413                                 preview_single_frame(scrub_pts_origin, stream_idx, FIRST_AT_OR_AFTER);
 414                         } else if (ClipList::Column(column) == ClipList::Column::OUT) {
 415                                 scrub_pts_origin = cliplist_clips->clip(row)->pts_out;
 416                                 preview_single_frame(scrub_pts_origin, stream_idx, LAST_BEFORE);
 417                         } else {
 418                                 return false;
 419                         }
 420                 } else {
 421                         if (PlayList::Column(column) == PlayList::Column::IN) {
 422                                 scrub_pts_origin = playlist_clips->clip(row)->pts_in;
 423                                 preview_single_frame(scrub_pts_origin, stream_idx, FIRST_AT_OR_AFTER);
 424                         } else if (PlayList::Column(column) == PlayList::Column::OUT) {
 425                                 scrub_pts_origin = playlist_clips->clip(row)->pts_out;
 426                                 preview_single_frame(scrub_pts_origin, stream_idx, LAST_BEFORE);
 427                         } else {
 428                                 return false;
 429                         }
 430                 }
 431
 432                 scrubbing = true;
 433                 scrub_row = row;
 434                 scrub_column = column;
 435                 scrub_x_origin = mouse->x();
 436                 scrub_type = type;
 437         } else if (event->type() == QEvent::MouseMove) {
 438                 if (scrubbing) {
 439                         QMouseEvent *mouse = (QMouseEvent *)event;
 440                         int offset = mouse->x() - scrub_x_origin;
 441                         int adjusted_offset;
 442                         if (offset >= dead_zone_pixels) {
 443                                 adjusted_offset = offset - dead_zone_pixels;
 444                         } else if (offset < -dead_zone_pixels) {
 445                                 adjusted_offset = offset + dead_zone_pixels;
 446                         } else {
 447                                 adjusted_offset = 0;
 448                         }
 449
 450                         int64_t pts = scrub_pts_origin + adjusted_offset * scrub_sensitivity;
 451                         currently_deferring_model_changes = true;
 452                         if (scrub_type == SCRUBBING_CLIP_LIST) {
 453                                 ClipProxy clip = cliplist_clips->mutable_clip(scrub_row);
 454                                 if (scrub_column == int(ClipList::Column::IN)) {
 455                                         current_change_id = "cliplist:in:" + to_string(scrub_row);
 456                                         set_pts_in(pts, current_pts, clip);
 457                                         preview_single_frame(pts, stream_idx, FIRST_AT_OR_AFTER);
 458                                 } else {
 459                                         current_change_id = "cliplist:out" + to_string(scrub_row);
 460                                         pts = std::max(pts, clip->pts_in);
 461                                         pts = std::min(pts, current_pts);
 462                                         clip->pts_out = pts;
 463                                         preview_single_frame(pts, stream_idx, LAST_BEFORE);
 464                                 }
 465                         } else {
 466                                 ClipProxy clip = playlist_clips->mutable_clip(scrub_row);
 467                                 if (scrub_column == int(PlayList::Column::IN)) {
 468                                         current_change_id = "playlist:in:" + to_string(scrub_row);
 469                                         set_pts_in(pts, current_pts, clip);
 470                                         preview_single_frame(pts, clip->stream_idx, FIRST_AT_OR_AFTER);
 471                                 } else {
 472                                         current_change_id = "playlist:out:" + to_string(scrub_row);
 473                                         pts = std::max(pts, clip->pts_in);
 474                                         pts = std::min(pts, current_pts);
 475                                         clip->pts_out = pts;
 476                                         preview_single_frame(pts, clip->stream_idx, LAST_BEFORE);
 477                                 }
 478                         }
 479                         currently_deferring_model_changes = false;
 480
 481                         return true;  // Don't use this mouse movement for selecting things.
 482                 }
 483         } else if (event->type() == QEvent::Wheel) {
 484                 QWheelEvent *wheel = (QWheelEvent *)event;
 485
 486                 QTableView *destination;
 487                 int in_column, out_column, camera_column;
 488                 if (watched == ui->clip_list->viewport()) {
 489                         destination = ui->clip_list;
 490                         in_column = int(ClipList::Column::IN);
 491                         out_column = int(ClipList::Column::OUT);
 492                         camera_column = -1;
 493                         last_mousewheel_camera_row = -1;
 494                 } else if (watched == ui->playlist->viewport()) {
 495                         destination = ui->playlist;
 496                         in_column = int(PlayList::Column::IN);
 497                         out_column = int(PlayList::Column::OUT);
 498                         camera_column = int(PlayList::Column::CAMERA);
 499                 } else {
 500                         last_mousewheel_camera_row = -1;
 501                         return false;
 502                 }
 503                 int column = destination->columnAt(wheel->x());
 504                 int row = destination->rowAt(wheel->y());
 505                 if (column == -1 || row == -1) return false;
 506
 507                 currently_deferring_model_changes = true;
 508                 {
 509                         current_change_id = (watched == ui->clip_list->viewport()) ? "cliplist:" : "playlist:";
 510                         ClipProxy clip = (watched == ui->clip_list->viewport()) ?
 511                                 cliplist_clips->mutable_clip(row) : playlist_clips->mutable_clip(row);
 512                         if (watched == ui->playlist->viewport()) {
 513                                 stream_idx = clip->stream_idx;
 514                         }
 515
 516                         if (column != camera_column) {
 517                                 last_mousewheel_camera_row = -1;
 518                         }
 519                         if (column == in_column) {
 520                                 current_change_id += "in:" + to_string(row);
 521                                 int64_t pts = clip->pts_in + wheel->angleDelta().y() * wheel_sensitivity;
 522                                 set_pts_in(pts, current_pts, clip);
 523                                 preview_single_frame(pts, stream_idx, FIRST_AT_OR_AFTER);
 524                         } else if (column == out_column) {
 525                                 current_change_id += "out:" + to_string(row);
 526                                 int64_t pts = clip->pts_out + wheel->angleDelta().y() * wheel_sensitivity;
 527                                 pts = std::max(pts, clip->pts_in);
 528                                 pts = std::min(pts, current_pts);
 529                                 clip->pts_out = pts;
 530                                 preview_single_frame(pts, stream_idx, LAST_BEFORE);
 531                         } else if (column == camera_column) {
 532                                 current_change_id += "camera:" + to_string(row);
 533                                 int angle_degrees = wheel->angleDelta().y();
 534                                 if (last_mousewheel_camera_row == row) {
 535                                         angle_degrees += leftover_angle_degrees;
 536                                 }
 537
 538                                 int stream_idx = clip->stream_idx + angle_degrees / camera_degrees_per_pixel;
 539                                 stream_idx = std::max(stream_idx, 0);
 540                                 stream_idx = std::min(stream_idx, NUM_CAMERAS - 1);
 541                                 clip->stream_idx = stream_idx;
 542
 543                                 last_mousewheel_camera_row = row;
 544                                 leftover_angle_degrees = angle_degrees % camera_degrees_per_pixel;
 545
 546                                 // Don't update the live view, that's rarely what the operator wants.
 547                         }
 548                 }
 549                 currently_deferring_model_changes = false;
 550         } else if (event->type() == QEvent::MouseButtonRelease) {
 551                 scrubbing = false;
 552         }
 553         return false;
 554 }
 555
 556 void MainWindow::preview_single_frame(int64_t pts, unsigned stream_idx, MainWindow::Rounding rounding)
 557 {
 558         if (rounding == LAST_BEFORE) {
 559                 lock_guard<mutex> lock(frame_mu);
 560                 if (frames[stream_idx].empty()) return;
 561                 auto it = lower_bound(frames[stream_idx].begin(), frames[stream_idx].end(), pts);
 562                 if (it != frames[stream_idx].end()) {
 563                         pts = *it;
 564                 }
 565         } else {
 566                 assert(rounding == FIRST_AT_OR_AFTER);
 567                 lock_guard<mutex> lock(frame_mu);
 568                 if (frames[stream_idx].empty()) return;
 569                 auto it = upper_bound(frames[stream_idx].begin(), frames[stream_idx].end(), pts - 1);
 570                 if (it != frames[stream_idx].end()) {
 571                         pts = *it;
 572                 }
 573         }
 574
 575         Clip fake_clip;
 576         fake_clip.pts_in = pts;
 577         fake_clip.pts_out = pts + 1;
 578         preview_player->play_clip(fake_clip, stream_idx);
 579 }
 580
 581 void MainWindow::playlist_selection_changed()
 582 {
 583         QItemSelectionModel *selected = ui->playlist->selectionModel();
 584         bool any_selected = selected->hasSelection();
 585         ui->playlist_duplicate_btn->setEnabled(any_selected);
 586         ui->playlist_remove_btn->setEnabled(any_selected);
 587         ui->playlist_move_up_btn->setEnabled(
 588                 any_selected && selected->selectedRows().front().row() > 0);
 589         ui->playlist_move_down_btn->setEnabled(
 590                 any_selected && selected->selectedRows().back().row() < int(playlist_clips->size()) - 1);
 591         ui->play_btn->setEnabled(!playlist_clips->empty());
 592 }