basic video viewer using fltk & embedded mpv. just drag&drop a folder and use left and right arrow. s to shuffle

pview.cc

// g++ -O2 -s -o pview main.cc -lfltk -lfltk_images -lmpv

#include <stdio.h>

#include <FL/Enumerations.H>
#include <FL/Fl.H>
#include <FL/Fl_Double_Window.H>
#include <FL/Fl_PNG_Image.H>
#include <FL/fl_draw.H>
#include <FL/x.H>

#include <mpv/client.h>

#if __linux__
#include <unistd.h>
#elif _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif

class MPVPlayer : public Fl_Window {
public:
  MPVPlayer(int x, int y, int w, int h, const char *label = "")
      : Fl_Window(x, y, w, h, label) {}
  ~MPVPlayer() { mpv_terminate_destroy(mpv); }

  void init() {
    mpv = mpv_create();
    uint64_t wid = fl_xid(this);
    mpv_set_property(mpv, "wid", MPV_FORMAT_INT64, &wid);
    mpv_set_property_string(mpv, "loop-file", "inf");
    mpv_initialize(mpv);
  }

  void startFile(const char *file) {
    if(!mpv)
      init();
    const char *mpv_cmd[] = {"loadfile", file, NULL};
    mpv_command(mpv, mpv_cmd);
  }

  void playlistNext() {
    if(!mpv)
      return;
    const char *mpv_cmd[] = {"playlist-next", NULL};
    mpv_command(mpv, mpv_cmd);
  }

  void playlistPrev() {
    if(!mpv)
      return;
    const char *mpv_cmd[] = {"playlist-prev", NULL};
    mpv_command(mpv, mpv_cmd);
  }

  void playlistShuffle() {
    if(!mpv)
      return;
    const char *mpv_cmd[] = {"playlist-shuffle", NULL};
    mpv_command(mpv, mpv_cmd);
  }

  void openFileManager() {
    if(!mpv)
      return;
    const char *path = mpv_get_property_string(mpv, "path");

#if __linux__
#define FILE_MANAGER "nemo"
    {
      char cmd[512] = {0};
      sprintf(cmd, "/bin/bash -c '" FILE_MANAGER " \"%s\"'", path);
      FILE *pf = popen(cmd, "r");
      pclose(pf);
    }
#elif _WIN32
    {
      char args[1024] = {0};
      sprintf(args, "/select, \"%s\"", path);
      ShellExecute(NULL, "explorer", args, NULL, NULL, 0);
    }
#else

#endif
    mpv_free((void *)path);
  }

  struct Timeout {
    MPVPlayer *player;
    double timeoutseconds;
  };

  static void timeout_cb(void *data) {
    Timeout *td = (Timeout *)data;
    td->player->playlistNext();
    Fl::repeat_timeout(td->timeoutseconds, MPVPlayer::timeout_cb, data);
  }

  int handle(int event) override {
    switch (event) {
    case FL_KEYBOARD: {
      switch (Fl::event_key()) {
      case 'n': // fallthrough
      case FL_Right: {
        playlistNext();
      } break;
      case 'p': // fallthrough
      case FL_Left: {
        playlistPrev();
      } break;
      case 's': {
        playlistShuffle();
      } break;
      case 'o': {
        openFileManager();
      } break;
      case 'a': {
        autoforward = !autoforward;
        if (autoforward)
          Fl::add_timeout(timeout.timeoutseconds, MPVPlayer::timeout_cb,
                          &timeout);
        else
          Fl::remove_timeout(MPVPlayer::timeout_cb, &timeout);
      } break;
      case FL_Up: {
        timeout.timeoutseconds += 0.5;
      } break;
      case FL_Down: {
        if (timeout.timeoutseconds > 1.0)
          timeout.timeoutseconds -= 0.5;
      } break;
      }
    } break;

    case FL_PASTE: {
      const char *file = Fl::event_text();
      char *fixed = strdup(file);
      size_t len = strlen(fixed);
      fixed[len - 1] = 0;
      startFile(fixed);
      free(fixed);
    }                    // fallthrough
    case FL_DND_DRAG:    // fallthrough
    case FL_DND_ENTER:   // fallthrough
    case FL_DND_LEAVE:   // fallthrough
    case FL_DND_RELEASE: // fallthrough
    case FL_FOCUS:       // fallthrough
      return 1;
    }
    return Fl_Window::handle(event);
  }

  void draw() override {
    if(mpv)
      Fl_Window::draw();
    else {
      fl_color(FL_BLACK);
      fl_font(FL_HELVETICA, 50);
      const char *text = "drag & drop a file/folder here";
      fl_draw(text, (w()-fl_width(text))/2, h()/2);
    }
  }

private:
  mpv_handle *mpv = nullptr;
  bool autoforward = false;
  Timeout timeout = {this, 3.0};
};

static char *initialFile = NULL;

static int args_cb(int argc, char **argv, int &i) {
  if (strcmp("-if", argv[i]) == 0) {
    if (i < argc - 1 && argv[i + 1] != 0) {
      initialFile = argv[i + 1];
      i += 2;
      return 2;
    }
  }
  return 0;
}

int main(int argc, char **argv) {
  int i = 0;
  Fl::args(argc, argv, i, &args_cb);
  auto win = Fl_Double_Window(1280, 720, "pview");
  auto player = MPVPlayer(0, 0, 1280, 720);
  win.icon(new Fl_PNG_Image("Awicons-Vista-Artistic-Folder-my-video.256.png"));
  win.add(player);
  win.resizable(player);
  win.end();
  win.show(argc, argv);
  if (initialFile != NULL)
    player.startFile(initialFile);
  Fl::focus(&player);
  return (Fl::run());
}