bigbluebutton-Github/bigbluebutton-html5/imports/api/slides/server/modifiers/displayThisSlide.js

import Slides from '/imports/api/slides';

export function displayThisSlide(meetingId, newSlideId, slideObject) {

  // grab the presentationId part of the slideId
  const presentationId = newSlideId.split('/')[0];

  // change current to false for the old slide
  Slides.update({
    presentationId: presentationId,
    'slide.current': true,
  }, {
    $set: {
      'slide.current': false,
    },
  });

  //change current to true for the new slide and update its ratios and offsets
  Slides.update({
    presentationId: presentationId,
    'slide.id': newSlideId,
  }, {
    $set: {
      'slide.current': true,
      'slide.height_ratio': slideObject.height_ratio,
      'slide.width_ratio': slideObject.width_ratio,
      'slide.x_offset': slideObject.x_offset,
      'slide.y_offset': slideObject.y_offset,
    },
  });
};