ngx-infinite-scroll
Version:
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JavaScript
import { of, fromEvent } from 'rxjs';
import { map, mergeMap, tap, throttleTime, filter } from 'rxjs/operators';
import { AxisResolver } from './axis-resolver';
import { shouldTriggerEvents } from './event-trigger';
import { resolveContainerElement } from './ngx-ins-utils';
import { calculatePoints, createResolver } from './position-resolver';
import * as ScrollResolver from './scroll-resolver';
import { ScrollState } from './scroll-state';
export function createScroller(config) {
const { scrollContainer, scrollWindow, element, fromRoot } = config;
const resolver = createResolver({
axis: new AxisResolver(!config.horizontal),
windowElement: resolveContainerElement(scrollContainer, scrollWindow, element, fromRoot),
});
const scrollState = new ScrollState({
totalToScroll: calculatePoints(element, resolver).totalToScroll,
});
const options = {
container: resolver.container,
throttle: config.throttle,
};
const distance = {
up: config.upDistance,
down: config.downDistance,
};
return attachScrollEvent(options).pipe(mergeMap(() => of(calculatePoints(element, resolver))), map((positionStats) => toInfiniteScrollParams(scrollState.lastScrollPosition, positionStats, distance)), tap(({ stats }) => scrollState.updateScroll(stats.scrolled, stats.totalToScroll)), filter(({ fire, scrollDown, stats: { totalToScroll } }) => shouldTriggerEvents(config.alwaysCallback, fire, scrollState.isTriggeredScroll(totalToScroll, scrollDown))), tap(({ scrollDown, stats: { totalToScroll } }) => {
scrollState.updateTriggeredFlag(totalToScroll, scrollDown);
}), map(toInfiniteScrollAction));
}
export function attachScrollEvent(options) {
let obs = fromEvent(options.container, 'scroll');
// For an unknown reason calling `sampleTime()` causes trouble for many users, even with `options.throttle = 0`.
// Let's avoid calling the function unless needed.
// Replacing with throttleTime seems to solve the problem
// See https://github.com/orizens/ngx-infinite-scroll/issues/198
if (options.throttle) {
obs = obs.pipe(throttleTime(options.throttle, undefined, {
leading: true,
trailing: true,
}));
}
return obs;
}
export function toInfiniteScrollParams(lastScrollPosition, stats, distance) {
const { scrollDown, fire } = ScrollResolver.getScrollStats(lastScrollPosition, stats, distance);
return {
scrollDown,
fire,
stats,
};
}
export const InfiniteScrollActions = {
DOWN: '[NGX_ISE] DOWN',
UP: '[NGX_ISE] UP',
};
export function toInfiniteScrollAction(response) {
const { scrollDown, stats: { scrolled: currentScrollPosition }, } = response;
return {
type: scrollDown ? InfiniteScrollActions.DOWN : InfiniteScrollActions.UP,
payload: {
currentScrollPosition,
},
};
}
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{ Observable, of, fromEvent } from 'rxjs';\nimport { map, mergeMap, tap, throttleTime, filter } from 'rxjs/operators';\n\nimport * as Models from '../../models';\nimport { AxisResolver } from './axis-resolver';\nimport { shouldTriggerEvents } from './event-trigger';\nimport { resolveContainerElement } from './ngx-ins-utils';\nimport { calculatePoints, createResolver } from './position-resolver';\nimport * as ScrollResolver from './scroll-resolver';\nimport { ScrollState } from './scroll-state';\n\nexport function createScroller(config: Models.IScroller) {\n  const { scrollContainer, scrollWindow, element, fromRoot } = config;\n  const resolver = createResolver({\n    axis: new AxisResolver(!config.horizontal),\n    windowElement: resolveContainerElement(\n      scrollContainer,\n      scrollWindow,\n      element,\n      fromRoot\n    ),\n  });\n  const scrollState = new ScrollState({\n    totalToScroll: calculatePoints(element, resolver).totalToScroll,\n  });\n  const options: Models.IScrollRegisterConfig = {\n    container: resolver.container,\n    throttle: config.throttle,\n  };\n  const distance = {\n    up: config.upDistance,\n    down: config.downDistance,\n  };\n  return attachScrollEvent(options).pipe(\n    mergeMap(() => of(calculatePoints(element, resolver))),\n    map((positionStats: Models.IPositionStats) =>\n      toInfiniteScrollParams(\n        scrollState.lastScrollPosition,\n        positionStats,\n        distance\n      )\n    ),\n    tap(({ stats }: Models.IScrollParams) =>\n      scrollState.updateScroll(stats.scrolled, stats.totalToScroll)\n    ),\n    filter(\n      ({ fire, scrollDown, stats: { totalToScroll } }: Models.IScrollParams) =>\n        shouldTriggerEvents(\n          config.alwaysCallback,\n          fire,\n          scrollState.isTriggeredScroll(totalToScroll, scrollDown)\n        )\n    ),\n    tap(({ scrollDown, stats: { totalToScroll } }: Models.IScrollParams) => {\n      scrollState.updateTriggeredFlag(totalToScroll, scrollDown);\n    }),\n    map(toInfiniteScrollAction)\n  );\n}\n\nexport function attachScrollEvent(\n  options: Models.IScrollRegisterConfig\n): Observable<{}> {\n  let obs = fromEvent(options.container, 'scroll');\n  // For an unknown reason calling `sampleTime()` causes trouble for many users, even with `options.throttle = 0`.\n  // Let's avoid calling the function unless needed.\n  // Replacing with throttleTime seems to solve the problem\n  // See https://github.com/orizens/ngx-infinite-scroll/issues/198\n  if (options.throttle) {\n    obs = obs.pipe(\n      throttleTime(options.throttle, undefined, {\n        leading: true,\n        trailing: true,\n      })\n    );\n  }\n  return obs as any;\n}\n\nexport function toInfiniteScrollParams(\n  lastScrollPosition: number,\n  stats: Models.IPositionStats,\n  distance: Models.IScrollerDistance\n): Models.IScrollParams {\n  const { scrollDown, fire } = ScrollResolver.getScrollStats(\n    lastScrollPosition,\n    stats,\n    distance\n  );\n  return {\n    scrollDown,\n    fire,\n    stats,\n  };\n}\n\nexport const InfiniteScrollActions = {\n  DOWN: '[NGX_ISE] DOWN',\n  UP: '[NGX_ISE] UP',\n};\n\nexport function toInfiniteScrollAction(\n  response: Models.IScrollParams\n): Models.IInfiniteScrollAction {\n  const {\n    scrollDown,\n    stats: { scrolled: currentScrollPosition },\n  } = response;\n  return {\n    type: scrollDown ? InfiniteScrollActions.DOWN : InfiniteScrollActions.UP,\n    payload: {\n      currentScrollPosition,\n    },\n  };\n}\n"]}