sandbox.js

// copied from chooseSaveFile function in ng_utils.js and adjusted to support directory selection
function chooseSaveToDirectory (dirName) {
  if (!$window.chrome || !chrome.fileSystem || !chrome.fileSystem.chooseEntry) {
    return qSync.reject()
  }
  var deferred = $q.defer()

  chrome.fileSystem.chooseEntry({
    type: 'openDirectory',
    suggestedName: dirName
  }, function (chosenDirectory) {
    deferred.resolve(chosenDirectory)
  })

  return deferred.promise
}


function downloadPhoto (photoID) {
      var photo = photos[photoID]
      var ext = 'jpg'
      var mimeType = 'image/jpeg'
      var fileName = 'photo' + photoID + '.' + ext
      var fullWidth = Math.max(screen.width || 0, $(window).width() - 36, 800)
      var fullHeight = Math.max(screen.height || 0, $(window).height() - 150, 800)
      var fullPhotoSize = choosePhotoSize(photo, fullWidth, fullHeight)
      var inputFileLocation = {
        _: 'inputFileLocation',
        volume_id: fullPhotoSize.location.volume_id,
        local_id: fullPhotoSize.location.local_id,
        secret: fullPhotoSize.location.secret
      }

      FileManager.chooseSave(fileName, ext, mimeType).then(function (writableFileEntry) {
        if (writableFileEntry) {
          MtpApiFileManager.downloadFile(
            fullPhotoSize.location.dc_id, inputFileLocation, fullPhotoSize.size, {
              mime: mimeType,
              toFileEntry: writableFileEntry
            }).then(function () {
            // console.log('file save done')
          }, function (e) {
            console.log('photo download failed', e)
          })
        }
      }, function () {
        var cachedBlob = MtpApiFileManager.getCachedFile(inputFileLocation)
        if (cachedBlob) {
          return FileManager.download(cachedBlob, mimeType, fileName)
        }

        MtpApiFileManager.downloadFile(
          fullPhotoSize.location.dc_id, inputFileLocation, fullPhotoSize.size, {
            mime: mimeType
          }
        ).then(function (blob) {
          FileManager.download(blob, mimeType, fileName)
        }, function (e) {
          console.log('photo download failed', e)
        })
      })
    }

//Choose Photo Size
photoSizePreference = 'full' || 'screenSize' || ''
    angular.forEach(photo.sizes, function (photoSize) {
      //photoSize.w
      //photoSize.h
      //  what else?
    }