GApps Script / Shuffle selected slides

gapps-shuffle-selected-slides.gs

function shuffle(array) {
  var currentIndex = array.length, temporaryValue, randomIndex

  while (0 !== currentIndex) {
    randomIndex = Math.floor(Math.random() * currentIndex)
    currentIndex -= 1
    temporaryValue = array[currentIndex]
    array[currentIndex] = array[randomIndex]
    array[randomIndex] = temporaryValue
  }

  return array
}


function shuffleSelectedSlides() {
  if (SlidesApp.getActivePresentation().getSelection().getSelectionType() !== SlidesApp.SelectionType.PAGE || SlidesApp.getActivePresentation().getSelection().getPageRange().getPages().length <= 1) {
    SlidesApp.getUi().alert('Cannot shuffle slides', 'Select 2 or more slides.', SlidesApp.getUi().ButtonSet.OK)
    return
  }

  var slideIds = SlidesApp.getActivePresentation().getSlides().map(function(slide) { return slide.getObjectId() })
  var selectedSlideIds = SlidesApp.getActivePresentation().getSelection().getPageRange().getPages().map(function(slide) { return slide.getObjectId() })
  var indexOffset = slideIds.indexOf(selectedSlideIds[0])
  var selectedSlides = SlidesApp.getActivePresentation().getSelection().getPageRange().getPages().map(function(page) { return page.asSlide() })
  shuffle(selectedSlides)
  selectedSlides.forEach(function(slide, index) {
    slide.move(index + indexOffset)
  })
}

function onOpen() {
  var ui = SlidesApp.getUi()
  ui.createMenu('≈ Extra ≈')
    .addItem('Shuffle selected slides', 'shuffleSelectedSlides')
    .addToUi()
}