virtual.js 10 KB

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  1. import { getDocument } from 'ssr-window';
  2. import { createElement, elementChildren, setCSSProperty } from '../../shared/utils.js';
  3. export default function Virtual({
  4. swiper,
  5. extendParams,
  6. on,
  7. emit
  8. }) {
  9. extendParams({
  10. virtual: {
  11. enabled: false,
  12. slides: [],
  13. cache: true,
  14. renderSlide: null,
  15. renderExternal: null,
  16. renderExternalUpdate: true,
  17. addSlidesBefore: 0,
  18. addSlidesAfter: 0
  19. }
  20. });
  21. let cssModeTimeout;
  22. const document = getDocument();
  23. swiper.virtual = {
  24. cache: {},
  25. from: undefined,
  26. to: undefined,
  27. slides: [],
  28. offset: 0,
  29. slidesGrid: []
  30. };
  31. const tempDOM = document.createElement('div');
  32. function renderSlide(slide, index) {
  33. const params = swiper.params.virtual;
  34. if (params.cache && swiper.virtual.cache[index]) {
  35. return swiper.virtual.cache[index];
  36. }
  37. // eslint-disable-next-line
  38. let slideEl;
  39. if (params.renderSlide) {
  40. slideEl = params.renderSlide.call(swiper, slide, index);
  41. if (typeof slideEl === 'string') {
  42. tempDOM.innerHTML = slideEl;
  43. slideEl = tempDOM.children[0];
  44. }
  45. } else if (swiper.isElement) {
  46. slideEl = createElement('swiper-slide');
  47. } else {
  48. slideEl = createElement('div', swiper.params.slideClass);
  49. }
  50. slideEl.setAttribute('data-swiper-slide-index', index);
  51. if (!params.renderSlide) {
  52. slideEl.innerHTML = slide;
  53. }
  54. if (params.cache) swiper.virtual.cache[index] = slideEl;
  55. return slideEl;
  56. }
  57. function update(force) {
  58. const {
  59. slidesPerView,
  60. slidesPerGroup,
  61. centeredSlides,
  62. loop: isLoop
  63. } = swiper.params;
  64. const {
  65. addSlidesBefore,
  66. addSlidesAfter
  67. } = swiper.params.virtual;
  68. const {
  69. from: previousFrom,
  70. to: previousTo,
  71. slides,
  72. slidesGrid: previousSlidesGrid,
  73. offset: previousOffset
  74. } = swiper.virtual;
  75. if (!swiper.params.cssMode) {
  76. swiper.updateActiveIndex();
  77. }
  78. const activeIndex = swiper.activeIndex || 0;
  79. let offsetProp;
  80. if (swiper.rtlTranslate) offsetProp = 'right';else offsetProp = swiper.isHorizontal() ? 'left' : 'top';
  81. let slidesAfter;
  82. let slidesBefore;
  83. if (centeredSlides) {
  84. slidesAfter = Math.floor(slidesPerView / 2) + slidesPerGroup + addSlidesAfter;
  85. slidesBefore = Math.floor(slidesPerView / 2) + slidesPerGroup + addSlidesBefore;
  86. } else {
  87. slidesAfter = slidesPerView + (slidesPerGroup - 1) + addSlidesAfter;
  88. slidesBefore = (isLoop ? slidesPerView : slidesPerGroup) + addSlidesBefore;
  89. }
  90. let from = activeIndex - slidesBefore;
  91. let to = activeIndex + slidesAfter;
  92. if (!isLoop) {
  93. from = Math.max(from, 0);
  94. to = Math.min(to, slides.length - 1);
  95. }
  96. let offset = (swiper.slidesGrid[from] || 0) - (swiper.slidesGrid[0] || 0);
  97. if (isLoop && activeIndex >= slidesBefore) {
  98. from -= slidesBefore;
  99. if (!centeredSlides) offset += swiper.slidesGrid[0];
  100. } else if (isLoop && activeIndex < slidesBefore) {
  101. from = -slidesBefore;
  102. if (centeredSlides) offset += swiper.slidesGrid[0];
  103. }
  104. Object.assign(swiper.virtual, {
  105. from,
  106. to,
  107. offset,
  108. slidesGrid: swiper.slidesGrid,
  109. slidesBefore,
  110. slidesAfter
  111. });
  112. function onRendered() {
  113. swiper.updateSlides();
  114. swiper.updateProgress();
  115. swiper.updateSlidesClasses();
  116. emit('virtualUpdate');
  117. }
  118. if (previousFrom === from && previousTo === to && !force) {
  119. if (swiper.slidesGrid !== previousSlidesGrid && offset !== previousOffset) {
  120. swiper.slides.forEach(slideEl => {
  121. slideEl.style[offsetProp] = `${offset - Math.abs(swiper.cssOverflowAdjustment())}px`;
  122. });
  123. }
  124. swiper.updateProgress();
  125. emit('virtualUpdate');
  126. return;
  127. }
  128. if (swiper.params.virtual.renderExternal) {
  129. swiper.params.virtual.renderExternal.call(swiper, {
  130. offset,
  131. from,
  132. to,
  133. slides: function getSlides() {
  134. const slidesToRender = [];
  135. for (let i = from; i <= to; i += 1) {
  136. slidesToRender.push(slides[i]);
  137. }
  138. return slidesToRender;
  139. }()
  140. });
  141. if (swiper.params.virtual.renderExternalUpdate) {
  142. onRendered();
  143. } else {
  144. emit('virtualUpdate');
  145. }
  146. return;
  147. }
  148. const prependIndexes = [];
  149. const appendIndexes = [];
  150. const getSlideIndex = index => {
  151. let slideIndex = index;
  152. if (index < 0) {
  153. slideIndex = slides.length + index;
  154. } else if (slideIndex >= slides.length) {
  155. // eslint-disable-next-line
  156. slideIndex = slideIndex - slides.length;
  157. }
  158. return slideIndex;
  159. };
  160. if (force) {
  161. swiper.slidesEl.querySelectorAll(`.${swiper.params.slideClass}, swiper-slide`).forEach(slideEl => {
  162. slideEl.remove();
  163. });
  164. } else {
  165. for (let i = previousFrom; i <= previousTo; i += 1) {
  166. if (i < from || i > to) {
  167. const slideIndex = getSlideIndex(i);
  168. swiper.slidesEl.querySelectorAll(`.${swiper.params.slideClass}[data-swiper-slide-index="${slideIndex}"], swiper-slide[data-swiper-slide-index="${slideIndex}"]`).forEach(slideEl => {
  169. slideEl.remove();
  170. });
  171. }
  172. }
  173. }
  174. const loopFrom = isLoop ? -slides.length : 0;
  175. const loopTo = isLoop ? slides.length * 2 : slides.length;
  176. for (let i = loopFrom; i < loopTo; i += 1) {
  177. if (i >= from && i <= to) {
  178. const slideIndex = getSlideIndex(i);
  179. if (typeof previousTo === 'undefined' || force) {
  180. appendIndexes.push(slideIndex);
  181. } else {
  182. if (i > previousTo) appendIndexes.push(slideIndex);
  183. if (i < previousFrom) prependIndexes.push(slideIndex);
  184. }
  185. }
  186. }
  187. appendIndexes.forEach(index => {
  188. swiper.slidesEl.append(renderSlide(slides[index], index));
  189. });
  190. if (isLoop) {
  191. for (let i = prependIndexes.length - 1; i >= 0; i -= 1) {
  192. const index = prependIndexes[i];
  193. swiper.slidesEl.prepend(renderSlide(slides[index], index));
  194. }
  195. } else {
  196. prependIndexes.sort((a, b) => b - a);
  197. prependIndexes.forEach(index => {
  198. swiper.slidesEl.prepend(renderSlide(slides[index], index));
  199. });
  200. }
  201. elementChildren(swiper.slidesEl, '.swiper-slide, swiper-slide').forEach(slideEl => {
  202. slideEl.style[offsetProp] = `${offset - Math.abs(swiper.cssOverflowAdjustment())}px`;
  203. });
  204. onRendered();
  205. }
  206. function appendSlide(slides) {
  207. if (typeof slides === 'object' && 'length' in slides) {
  208. for (let i = 0; i < slides.length; i += 1) {
  209. if (slides[i]) swiper.virtual.slides.push(slides[i]);
  210. }
  211. } else {
  212. swiper.virtual.slides.push(slides);
  213. }
  214. update(true);
  215. }
  216. function prependSlide(slides) {
  217. const activeIndex = swiper.activeIndex;
  218. let newActiveIndex = activeIndex + 1;
  219. let numberOfNewSlides = 1;
  220. if (Array.isArray(slides)) {
  221. for (let i = 0; i < slides.length; i += 1) {
  222. if (slides[i]) swiper.virtual.slides.unshift(slides[i]);
  223. }
  224. newActiveIndex = activeIndex + slides.length;
  225. numberOfNewSlides = slides.length;
  226. } else {
  227. swiper.virtual.slides.unshift(slides);
  228. }
  229. if (swiper.params.virtual.cache) {
  230. const cache = swiper.virtual.cache;
  231. const newCache = {};
  232. Object.keys(cache).forEach(cachedIndex => {
  233. const cachedEl = cache[cachedIndex];
  234. const cachedElIndex = cachedEl.getAttribute('data-swiper-slide-index');
  235. if (cachedElIndex) {
  236. cachedEl.setAttribute('data-swiper-slide-index', parseInt(cachedElIndex, 10) + numberOfNewSlides);
  237. }
  238. newCache[parseInt(cachedIndex, 10) + numberOfNewSlides] = cachedEl;
  239. });
  240. swiper.virtual.cache = newCache;
  241. }
  242. update(true);
  243. swiper.slideTo(newActiveIndex, 0);
  244. }
  245. function removeSlide(slidesIndexes) {
  246. if (typeof slidesIndexes === 'undefined' || slidesIndexes === null) return;
  247. let activeIndex = swiper.activeIndex;
  248. if (Array.isArray(slidesIndexes)) {
  249. for (let i = slidesIndexes.length - 1; i >= 0; i -= 1) {
  250. swiper.virtual.slides.splice(slidesIndexes[i], 1);
  251. if (swiper.params.virtual.cache) {
  252. delete swiper.virtual.cache[slidesIndexes[i]];
  253. }
  254. if (slidesIndexes[i] < activeIndex) activeIndex -= 1;
  255. activeIndex = Math.max(activeIndex, 0);
  256. }
  257. } else {
  258. swiper.virtual.slides.splice(slidesIndexes, 1);
  259. if (swiper.params.virtual.cache) {
  260. delete swiper.virtual.cache[slidesIndexes];
  261. }
  262. if (slidesIndexes < activeIndex) activeIndex -= 1;
  263. activeIndex = Math.max(activeIndex, 0);
  264. }
  265. update(true);
  266. swiper.slideTo(activeIndex, 0);
  267. }
  268. function removeAllSlides() {
  269. swiper.virtual.slides = [];
  270. if (swiper.params.virtual.cache) {
  271. swiper.virtual.cache = {};
  272. }
  273. update(true);
  274. swiper.slideTo(0, 0);
  275. }
  276. on('beforeInit', () => {
  277. if (!swiper.params.virtual.enabled) return;
  278. let domSlidesAssigned;
  279. if (typeof swiper.passedParams.virtual.slides === 'undefined') {
  280. const slides = [...swiper.slidesEl.children].filter(el => el.matches(`.${swiper.params.slideClass}, swiper-slide`));
  281. if (slides && slides.length) {
  282. swiper.virtual.slides = [...slides];
  283. domSlidesAssigned = true;
  284. slides.forEach((slideEl, slideIndex) => {
  285. slideEl.setAttribute('data-swiper-slide-index', slideIndex);
  286. swiper.virtual.cache[slideIndex] = slideEl;
  287. slideEl.remove();
  288. });
  289. }
  290. }
  291. if (!domSlidesAssigned) {
  292. swiper.virtual.slides = swiper.params.virtual.slides;
  293. }
  294. swiper.classNames.push(`${swiper.params.containerModifierClass}virtual`);
  295. swiper.params.watchSlidesProgress = true;
  296. swiper.originalParams.watchSlidesProgress = true;
  297. if (!swiper.params.initialSlide) {
  298. update();
  299. }
  300. });
  301. on('setTranslate', () => {
  302. if (!swiper.params.virtual.enabled) return;
  303. if (swiper.params.cssMode && !swiper._immediateVirtual) {
  304. clearTimeout(cssModeTimeout);
  305. cssModeTimeout = setTimeout(() => {
  306. update();
  307. }, 100);
  308. } else {
  309. update();
  310. }
  311. });
  312. on('init update resize', () => {
  313. if (!swiper.params.virtual.enabled) return;
  314. if (swiper.params.cssMode) {
  315. setCSSProperty(swiper.wrapperEl, '--swiper-virtual-size', `${swiper.virtualSize}px`);
  316. }
  317. });
  318. Object.assign(swiper.virtual, {
  319. appendSlide,
  320. prependSlide,
  321. removeSlide,
  322. removeAllSlides,
  323. update
  324. });
  325. }