Refactor main.js: playback and subtitles controllers

renderer/controllers/playback-controller.js

@@ -0,0 +1,299 @@
+const electron = require('electron')
+const path = require('path')
+
+const Cast = require('../lib/cast')
+const {dispatch} = require('../lib/dispatcher')
+const telemetry = require('../lib/telemetry')
+const errors = require('../lib/errors')
+const sound = require('../lib/sound')
+const TorrentPlayer = require('../lib/torrent-player')
+const TorrentSummary = require('../lib/torrent-summary')
+const State = require('../lib/state')
+
+const ipcRenderer = electron.ipcRenderer
+
+// Controls playback of torrents and files within torrents
+// both local (<video>,<audio>,VLC) and remote (cast)
+module.exports = class PlaybackController {
+  constructor (state, config, update) {
+    this.state = state
+    this.config = config
+    this.update = update
+  }
+
+  // Play a file in a torrent.
+  // * Start torrenting, if necessary
+  // * Stream, if not already fully downloaded
+  // * If no file index is provided, pick the default file to play
+  playFile (infoHash, index /* optional */) {
+    this.state.location.go({
+      url: 'player',
+      onbeforeload: (cb) => {
+        this.play()
+        openPlayer(this.state, infoHash, index, cb)
+      },
+      onbeforeunload: (cb) => closePlayer(this.state, this.config, cb)
+    }, (err) => {
+      if (err) dispatch('error', err)
+    })
+  }
+
+  // Show a file in the OS, eg in Finder on a Mac
+  openItem (infoHash, index) {
+    var torrentSummary = torrentSummary.getByKey(this.state, infoHash)
+    var filePath = path.join(
+      torrentSummary.path,
+      torrentSummary.files[index].path)
+    ipcRenderer.send('openItem', filePath)
+  }
+
+  // Toggle (play or pause) the currently playing media
+  playPause () {
+    var state = this.state
+    if (state.location.url() !== 'player') return
+
+    // force rerendering if window is hidden,
+    // in order to bypass `raf` and play/pause media immediately
+    if (!state.window.isVisible) {
+      var mediaTag = document.querySelector('video,audio')
+      if (state.playing.isPaused) mediaTag.play()
+      else mediaTag.pause()
+    }
+
+    if (state.playing.isPaused) this.play()
+    else this.pause()
+  }
+
+  // Play (unpause) the current media
+  play () {
+    var state = this.state
+    if (!state.playing.isPaused) return
+    state.playing.isPaused = false
+    if (isCasting(state)) {
+      Cast.play()
+    }
+    ipcRenderer.send('onPlayerPlay')
+  }
+
+  // Pause the currently playing media
+  pause () {
+    var state = this.state
+    if (state.playing.isPaused) return
+    state.playing.isPaused = true
+    if (isCasting(state)) {
+      Cast.pause()
+    }
+    ipcRenderer.send('onPlayerPause')
+  }
+
+  // Skip (aka seek) to a specific point, in seconds
+  skipTo (time) {
+    if (isCasting(this.state)) Cast.seek(time)
+    else this.state.playing.jumpToTime = time
+  }
+
+  // Change playback speed. 1 = faster, -1 = slower
+  // Playback speed ranges from 16 (fast forward) to 1 (normal playback)
+  // to 0.25 (quarter-speed playback), then goes to -0.25, -0.5, -1, -2, etc
+  // until -16 (fast rewind)
+  changePlaybackRate (direction) {
+    var state = this.state
+    var rate = state.playing.playbackRate
+    if (direction > 0 && rate >= 0.25 && rate < 2) {
+      rate += 0.25
+    } else if (direction < 0 && rate > 0.25 && rate <= 2) {
+      rate -= 0.25
+    } else if (direction < 0 && rate === 0.25) { /* when we set playback rate at 0 in html 5, playback hangs ;( */
+      rate = -1
+    } else if (direction > 0 && rate === -1) {
+      rate = 0.25
+    } else if ((direction > 0 && rate >= 1 && rate < 16) || (direction < 0 && rate > -16 && rate <= -1)) {
+      rate *= 2
+    } else if ((direction < 0 && rate > 1 && rate <= 16) || (direction > 0 && rate >= -16 && rate < -1)) {
+      rate /= 2
+    }
+    state.playing.playbackRate = rate
+    if (isCasting(state) && !Cast.setRate(rate)) {
+      state.playing.playbackRate = 1
+    }
+  }
+
+  // Change the volume, in range [0, 1], by some amount
+  // For example, volume muted (0), changeVolume (0.3) increases to 30% volume
+  changeVolume (delta) {
+    // change volume with delta value
+    this.setVolume(this.state.playing.volume + delta)
+  }
+
+  // Set the volume to some value in [0, 1]
+  setVolume (volume) {
+    // check if its in [0.0 - 1.0] range
+    volume = Math.max(0, Math.min(1, volume))
+
+    var state = this.state
+    if (isCasting(state)) {
+      Cast.setVolume(volume)
+    } else {
+      state.playing.setVolume = volume
+    }
+  }
+
+  // Hide player controls while playing video, if the mouse stays still for a while
+  // Never hide the controls when:
+  // * The mouse is over the controls or we're scrubbing (see CSS)
+  // * The video is paused
+  // * The video is playing remotely on Chromecast or Airplay
+  showOrHidePlayerControls () {
+    var state = this.state
+    var hideControls = state.location.url() === 'player' &&
+      state.playing.mouseStationarySince !== 0 &&
+      new Date().getTime() - state.playing.mouseStationarySince > 2000 &&
+      !state.playing.isPaused &&
+      state.playing.location === 'local'
+
+    if (hideControls !== state.playing.hideControls) {
+      state.playing.hideControls = hideControls
+      return true
+    }
+    return false
+  }
+}
+
+// Opens the video player to a specific torrent
+function openPlayer (state, infoHash, index, cb) {
+  var torrentSummary = TorrentSummary.getByKey(state, infoHash)
+
+  // automatically choose which file in the torrent to play, if necessary
+  if (index === undefined) index = torrentSummary.defaultPlayFileIndex
+  if (index === undefined) index = TorrentPlayer.pickFileToPlay(torrentSummary.files)
+  if (index === undefined) return cb(new errors.UnplayableError())
+
+  // update UI to show pending playback
+  if (torrentSummary.progress !== 1) sound.play('PLAY')
+  // TODO: remove torrentSummary.playStatus
+  torrentSummary.playStatus = 'requested'
+  this.update()
+
+  var timeout = setTimeout(() => {
+    telemetry.logPlayAttempt('timeout')
+    // TODO: remove torrentSummary.playStatus
+    torrentSummary.playStatus = 'timeout' /* no seeders available? */
+    sound.play('ERROR')
+    cb(new Error('Playback timed out. Try again.'))
+    this.update()
+  }, 10000) /* give it a few seconds */
+
+  if (torrentSummary.status === 'paused') {
+    dispatch('startTorrentingSummary', torrentSummary)
+    ipcRenderer.once('wt-ready-' + torrentSummary.infoHash,
+      () => openPlayerFromActiveTorrent(state, torrentSummary, index, timeout, cb))
+  } else {
+    openPlayerFromActiveTorrent(state, torrentSummary, index, timeout, cb)
+  }
+}
+
+function openPlayerFromActiveTorrent (state, torrentSummary, index, timeout, cb) {
+  var fileSummary = torrentSummary.files[index]
+
+  // update state
+  state.playing.infoHash = torrentSummary.infoHash
+  state.playing.fileIndex = index
+  state.playing.type = TorrentPlayer.isVideo(fileSummary) ? 'video'
+    : TorrentPlayer.isAudio(fileSummary) ? 'audio'
+    : 'other'
+
+  // pick up where we left off
+  if (fileSummary.currentTime) {
+    var fraction = fileSummary.currentTime / fileSummary.duration
+    var secondsLeft = fileSummary.duration - fileSummary.currentTime
+    if (fraction < 0.9 && secondsLeft > 10) {
+      state.playing.jumpToTime = fileSummary.currentTime
+    }
+  }
+
+  // if it's audio, parse out the metadata (artist, title, etc)
+  if (state.playing.type === 'audio' && !fileSummary.audioInfo) {
+    ipcRenderer.send('wt-get-audio-metadata', torrentSummary.infoHash, index)
+  }
+
+  // if it's video, check for subtitles files that are done downloading
+  dispatch('checkForSubtitles')
+
+  ipcRenderer.send('wt-start-server', torrentSummary.infoHash, index)
+  ipcRenderer.once('wt-server-' + torrentSummary.infoHash, (e, info) => {
+    clearTimeout(timeout)
+
+    // if we timed out (user clicked play a long time ago), don't autoplay
+    var timedOut = torrentSummary.playStatus === 'timeout'
+    delete torrentSummary.playStatus
+    if (timedOut) {
+      ipcRenderer.send('wt-stop-server')
+      return this.update()
+    }
+
+    // otherwise, play the video
+    state.window.title = torrentSummary.files[state.playing.fileIndex].name
+    this.update()
+
+    ipcRenderer.send('onPlayerOpen')
+
+    cb()
+  })
+}
+
+function closePlayer (state, config, cb) {
+  console.log('closePlayer')
+
+  // Quit any external players, like Chromecast/Airplay/etc or VLC
+  if (isCasting(state)) {
+    Cast.stop()
+  }
+  if (state.playing.location === 'vlc') {
+    ipcRenderer.send('vlcQuit')
+  }
+
+  // Save volume (this session only, not in state.saved)
+  state.previousVolume = state.playing.volume
+
+  // Telemetry: track what happens after the user clicks play
+  var result = state.playing.result // 'success' or 'error'
+  if (result === 'success') telemetry.logPlayAttempt('success') // first frame displayed
+  else if (result === 'error') telemetry.logPlayAttempt('error') // codec missing, etc
+  else if (result === undefined) telemetry.logPlayAttempt('abandoned') // user exited before first frame
+  else console.error('Unknown state.playing.result', state.playing.result)
+
+  // Reset the window contents back to the home screen
+  state.window.title = config.APP_WINDOW_TITLE
+  state.playing = State.getDefaultPlayState()
+  state.server = null
+
+  // Reset the window size and location back to where it was
+  if (state.window.isFullScreen) {
+    dispatch('toggleFullScreen', false)
+  }
+  restoreBounds(state)
+
+  // Tell the WebTorrent process to kill the torrent-to-HTTP server
+  ipcRenderer.send('wt-stop-server')
+
+  ipcRenderer.send('onPlayerClose')
+
+  this.update()
+  cb()
+}
+
+// Checks whether we are connected and already casting
+// Returns false if we not casting (state.playing.location === 'local')
+// or if we're trying to connect but haven't yet ('chromecast-pending', etc)
+function isCasting (state) {
+  return state.playing.location === 'chromecast' ||
+    state.playing.location === 'airplay' ||
+    state.playing.location === 'dlna'
+}
+
+function restoreBounds (state) {
+  ipcRenderer.send('setAspectRatio', 0)
+  if (state.window.bounds) {
+    ipcRenderer.send('setBounds', state.window.bounds, false)
+  }
+}

renderer/controllers/subtitles-controller.js

@@ -0,0 +1,134 @@
+const electron = require('electron')
+const fs = require('fs-extra')
+const path = require('path')
+const parallel = require('run-parallel')
+
+const {dispatch} = require('../lib/dispatcher')
+
+module.exports = class SubtitlesController {
+  constructor (state) {
+    this.state = state
+  }
+
+  openSubtitles () {
+    electron.remote.dialog.showOpenDialog({
+      title: 'Select a subtitles file.',
+      filters: [ { name: 'Subtitles', extensions: ['vtt', 'srt'] } ],
+      properties: [ 'openFile' ]
+    }, (filenames) => {
+      if (!Array.isArray(filenames)) return
+      this.addSubtitles(filenames, true)
+    })
+  }
+
+  selectSubtitle (ix) {
+    this.state.playing.subtitles.selectedIndex = ix
+  }
+
+  toggleSubtitlesMenu () {
+    var subtitles = this.state.playing.subtitles
+    subtitles.showMenu = !subtitles.showMenu
+  }
+
+  addSubtitles (files, autoSelect) {
+    // Subtitles are only supported when playing video files
+    if (this.state.playing.type !== 'video') return
+    if (files.length === 0) return
+    var subtitles = this.state.playing.subtitles
+
+    // Read the files concurrently, then add all resulting subtitle tracks
+    var tasks = files.map((file) => (cb) => loadSubtitle(file, cb))
+    parallel(tasks, function (err, tracks) {
+      if (err) return dispatch('error', err)
+
+      for (var i = 0; i < tracks.length; i++) {
+        // No dupes allowed
+        var track = tracks[i]
+        if (subtitles.tracks.some(
+          (t) => track.filePath === t.filePath)) continue
+
+        // Add the track
+        subtitles.tracks.push(track)
+
+        // If we're auto-selecting a track, try to find one in the user's language
+        if (autoSelect && (i === 0 || isSystemLanguage(track.language))) {
+          subtitles.selectedIndex = subtitles.tracks.length - 1
+        }
+      }
+
+      // Finally, make sure no two tracks have the same label
+      relabelSubtitles(subtitles)
+    })
+  }
+
+  checkForSubtitles () {
+    if (this.state.playing.type !== 'video') return
+    var torrentSummary = this.state.getPlayingTorrentSummary()
+    if (!torrentSummary || !torrentSummary.progress) return
+
+    torrentSummary.progress.files.forEach((fp, ix) => {
+      if (fp.numPieces !== fp.numPiecesPresent) return // ignore incomplete files
+      var file = torrentSummary.files[ix]
+      if (!this.isSubtitle(file.name)) return
+      var filePath = path.join(torrentSummary.path, file.path)
+      this.addSubtitles([filePath], false)
+    })
+  }
+
+  isSubtitle (file) {
+    var name = typeof file === 'string' ? file : file.name
+    var ext = path.extname(name).toLowerCase()
+    return ext === '.srt' || ext === '.vtt'
+  }
+}
+
+function loadSubtitle (file, cb) {
+  // Lazy load to keep startup fast
+  var concat = require('simple-concat')
+  var LanguageDetect = require('languagedetect')
+  var srtToVtt = require('srt-to-vtt')
+
+  // Read the .SRT or .VTT file, parse it, add subtitle track
+  var filePath = file.path || file
+
+  var vttStream = fs.createReadStream(filePath).pipe(srtToVtt())
+
+  concat(vttStream, function (err, buf) {
+    if (err) return dispatch('error', 'Can\'t parse subtitles file.')
+
+    // Detect what language the subtitles are in
+    var vttContents = buf.toString().replace(/(.*-->.*)/g, '')
+    var langDetected = (new LanguageDetect()).detect(vttContents, 2)
+    langDetected = langDetected.length ? langDetected[0][0] : 'subtitle'
+    langDetected = langDetected.slice(0, 1).toUpperCase() + langDetected.slice(1)
+
+    var track = {
+      buffer: 'data:text/vtt;base64,' + buf.toString('base64'),
+      language: langDetected,
+      label: langDetected,
+      filePath: filePath
+    }
+
+    cb(null, track)
+  })
+}
+
+// Checks whether a language name like "English" or "German" matches the system
+// language, aka the current locale
+function isSystemLanguage (language) {
+  var iso639 = require('iso-639-1')
+  var osLangISO = window.navigator.language.split('-')[0] // eg "en"
+  var langIso = iso639.getCode(language) // eg "de" if language is "German"
+  return langIso === osLangISO
+}
+
+// Make sure we don't have two subtitle tracks with the same label
+// Labels each track by language, eg "German", "English", "English 2", ...
+function relabelSubtitles (subtitles) {
+  var counts = {}
+  subtitles.tracks.forEach(function (track) {
+    var lang = track.language
+    counts[lang] = (counts[lang] || 0) + 1
+    track.label = counts[lang] > 1 ? (lang + ' ' + counts[lang]) : lang
+  })
+}