swiper/core/breakpoints/setBreakpoint.js

import { extend } from '../../shared/utils.js';

const isGridEnabled = (swiper, params) => {
  return swiper.grid && params.grid && params.grid.rows > 1;
};

export default function setBreakpoint() {
  const swiper = this;
  const {
    activeIndex,
    initialized,
    loopedSlides = 0,
    params,
    $el
  } = swiper;
  const breakpoints = params.breakpoints;
  if (!breakpoints || breakpoints && Object.keys(breakpoints).length === 0) return; // Get breakpoint for window width and update parameters

  const breakpoint = swiper.getBreakpoint(breakpoints, swiper.params.breakpointsBase, swiper.el);
  if (!breakpoint || swiper.currentBreakpoint === breakpoint) return;
  const breakpointOnlyParams = breakpoint in breakpoints ? breakpoints[breakpoint] : undefined;
  const breakpointParams = breakpointOnlyParams || swiper.originalParams;
  const wasMultiRow = isGridEnabled(swiper, params);
  const isMultiRow = isGridEnabled(swiper, breakpointParams);
  const wasEnabled = params.enabled;

  if (wasMultiRow && !isMultiRow) {
    $el.removeClass(`${params.containerModifierClass}grid ${params.containerModifierClass}grid-column`);
    swiper.emitContainerClasses();
  } else if (!wasMultiRow && isMultiRow) {
    $el.addClass(`${params.containerModifierClass}grid`);

    if (breakpointParams.grid.fill && breakpointParams.grid.fill === 'column' || !breakpointParams.grid.fill && params.grid.fill === 'column') {
      $el.addClass(`${params.containerModifierClass}grid-column`);
    }

    swiper.emitContainerClasses();
  }

  const directionChanged = breakpointParams.direction && breakpointParams.direction !== params.direction;
  const needsReLoop = params.loop && (breakpointParams.slidesPerView !== params.slidesPerView || directionChanged);

  if (directionChanged && initialized) {
    swiper.changeDirection();
  }

  extend(swiper.params, breakpointParams);
  const isEnabled = swiper.params.enabled;
  Object.assign(swiper, {
    allowTouchMove: swiper.params.allowTouchMove,
    allowSlideNext: swiper.params.allowSlideNext,
    allowSlidePrev: swiper.params.allowSlidePrev
  });

  if (wasEnabled && !isEnabled) {
    swiper.disable();
  } else if (!wasEnabled && isEnabled) {
    swiper.enable();
  }

  swiper.currentBreakpoint = breakpoint;
  swiper.emit('_beforeBreakpoint', breakpointParams);

  if (needsReLoop && initialized) {
    swiper.loopDestroy();
    swiper.loopCreate();
    swiper.updateSlides();
    swiper.slideTo(activeIndex - loopedSlides + swiper.loopedSlides, 0, false);
  }

  swiper.emit('breakpoint', breakpointParams);
}