mirror of
https://github.com/ionic-team/ionic-framework.git
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perf(virtual-scroll): improve virtual-scroll performance
This commit is contained in:
Adam Bradley
@ -1,10 +1,9 @@
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import { AfterContentInit, ChangeDetectorRef, ContentChild, ContentChildren, Directive, DoCheck, ElementRef, Input, IterableDiffers, IterableDiffer, NgZone, OnDestroy, Optional, QueryList, Renderer, TrackByFn } from '@angular/core';
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import { AfterContentInit, ChangeDetectorRef, ContentChild, Directive, DoCheck, ElementRef, Input, IterableDiffers, IterableDiffer, NgZone, OnDestroy, Optional, Renderer, TrackByFn } from '@angular/core';
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import { adjustRendered, calcDimensions, estimateHeight, initReadNodes, processRecords, populateNodeData, updateDimensions, writeToNodes } from './virtual-util';
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import { clearNativeTimeout, nativeRaf, nativeTimeout } from '../../util/dom';
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import { adjustRendered, calcDimensions, estimateHeight, initReadNodes, processRecords, populateNodeData, updateDimensions, updateNodeContext, writeToNodes } from './virtual-util';
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import { Config } from '../../config/config';
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import { Content } from '../content/content';
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import { Img } from '../img/img';
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import { Content, ScrollEvent } from '../content/content';
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import { DomController } from '../../util/dom-controller';
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import { isBlank, isFunction, isPresent } from '../../util/util';
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import { Platform } from '../../platform/platform';
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import { ViewController } from '../../navigation/view-controller';
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@ -186,10 +185,9 @@ import { VirtualFooter, VirtualHeader, VirtualItem } from './virtual-item';
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export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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_trackBy: TrackByFn;
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_differ: IterableDiffer;
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_unreg: Function;
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_scrollSub: any;
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_scrollEndSub: any;
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_init: boolean;
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_rafId: number;
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_tmId: number;
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_hdrFn: Function;
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_ftrFn: Function;
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_records: any[] = [];
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@ -200,13 +198,12 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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_data: VirtualData = {
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scrollTop: 0,
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};
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_eventAssist: boolean;
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_queue: number = null;
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_queue: ScrollQueue = null;
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@ContentChild(VirtualItem) _itmTmp: VirtualItem;
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@ContentChild(VirtualHeader) _hdrTmp: VirtualHeader;
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@ContentChild(VirtualFooter) _ftrTmp: VirtualFooter;
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@ContentChildren(Img) _imgs: QueryList<Img>;
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/**
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* @input {array} The data that builds the templates within the virtual scroll.
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@ -338,6 +335,8 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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this._trackBy = val;
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}
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private _hasUpdate = false;
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constructor(
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private _iterableDiffers: IterableDiffers,
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private _elementRef: ElementRef,
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@ -347,16 +346,85 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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private _content: Content,
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private _platform: Platform,
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@Optional() private _ctrl: ViewController,
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config: Config) {
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this._eventAssist = config.getBoolean('virtualScrollEventAssist');
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config: Config,
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private _dom: DomController) {
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// hide the virtual scroll element with opacity so we don't
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// see jank as it loads up, but we're still able to read
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// dimensions because it's still rendered and only opacity hidden
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this._renderer.setElementClass(_elementRef.nativeElement, 'virtual-loading', true);
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// wait for the content to be rendered and has readable dimensions
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_content.readReady.subscribe(() => {
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this.readUpdate(true, true);
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if (!this._scrollSub) {
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// listen for scroll events
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this.addScrollListener(config.getBoolean('virtualScrollEventAssist'));
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}
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});
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// wait for the content to be writable
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_content.writeReady.subscribe(() => {
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this.writeUpdate();
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});
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}
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readUpdate(checkDataChanges: boolean, dimensionsUpdated: boolean) {
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if (!this._records) return;
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if (checkDataChanges && !dimensionsUpdated) {
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if (isPresent(this._differ) && !isPresent(this._differ.diff(this._records))) {
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// no changes
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return;
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}
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}
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console.debug(`virtual-scroll, readUpdate, checkDataChanges: ${checkDataChanges}, dimensionsUpdated: ${dimensionsUpdated}`);
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this._hasUpdate = true;
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// reset everything
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this._cells.length = 0;
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this._nodes.length = 0;
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this._itmTmp.viewContainer.clear();
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// ******** DOM READ ****************
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calcDimensions(this._data, this._elementRef.nativeElement,
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this.approxItemWidth, this.approxItemHeight,
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this.approxHeaderWidth, this.approxHeaderHeight,
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this.approxFooterWidth, this.approxFooterHeight,
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this.bufferRatio);
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}
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writeUpdate() {
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if (!this._hasUpdate) {
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return;
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}
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console.debug(`virtual-scroll, writeUpdate`);
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processRecords(this._data.renderHeight,
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this._records,
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this._cells,
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this._hdrFn,
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this._ftrFn,
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this._data);
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// ******** DOM WRITE ****************
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this.renderVirtual();
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this._hasUpdate = false;
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}
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/**
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* @private
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*/
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ngDoCheck() {
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if (this._init) {
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this.update(true);
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this.readUpdate(true, false);
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this.writeUpdate();
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}
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}
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@ -377,98 +445,32 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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console.warn('Virtual Scroll: Please provide an "approxItemHeight" input to ensure proper virtual scroll rendering');
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}
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this.update(true);
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this._platform.onResize(() => {
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console.debug('VirtualScroll, onResize');
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this.update(false);
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});
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// this.update(true);
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// this._platform.onResize(() => {
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// console.debug('VirtualScroll, onResize');
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// this.update(false);
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// });
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}
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}
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/**
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* @private
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* DOM READ THEN DOM WRITE
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*/
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update(checkChanges: boolean) {
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const self = this;
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if (!self._records) return;
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if (checkChanges) {
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if (isPresent(self._differ)) {
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let changes = self._differ.diff(self._records);
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if (!isPresent(changes)) return;
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}
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}
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console.debug('VirtualScroll, update, records:', self._records.length);
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// reset everything
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self._cells.length = 0;
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self._nodes.length = 0;
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self._itmTmp.viewContainer.clear();
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self._elementRef.nativeElement.parentElement.scrollTop = 0;
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let attempts = 0;
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function readDimensions(done: Function/* cuz promises add unnecessary overhead here */) {
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if (self._data.valid) {
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// good to go, we already have good dimension data
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done();
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} else {
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// ******** DOM READ ****************
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calcDimensions(self._data, self._elementRef.nativeElement.parentElement,
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self.approxItemWidth, self.approxItemHeight,
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self.approxHeaderWidth, self.approxHeaderHeight,
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self.approxFooterWidth, self.approxFooterHeight,
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self.bufferRatio);
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if (self._data.valid) {
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// sweet, we got some good dimension data!
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done();
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} else if (attempts < 30) {
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// oh no! the DOM doesn't have good data yet!
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// let's try again in XXms, and give up eventually if we never get data
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attempts++;
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nativeRaf(function() {
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readDimensions(done);
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});
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}
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}
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}
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// ******** DOM READ ****************
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readDimensions(function() {
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processRecords(self._data.renderHeight,
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self._records,
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self._cells,
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self._hdrFn,
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self._ftrFn,
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self._data);
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// ******** DOM WRITE ****************
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self.renderVirtual();
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// list for scroll events
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self.addScrollListener();
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});
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}
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/**
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* @private
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* DOM WRITE
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*/
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renderVirtual() {
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// initialize nodes with the correct cell data
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this._data.topCell = 0;
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this._data.bottomCell = (this._cells.length - 1);
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const nodes = this._nodes;
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const cells = this._cells;
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const data = this._data;
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const records = this._records;
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populateNodeData(0, this._data.bottomCell,
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this._data.viewWidth, true,
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this._cells, this._records, this._nodes,
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// initialize nodes with the correct cell data
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data.topCell = 0;
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data.bottomCell = (cells.length - 1);
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populateNodeData(0, data.bottomCell,
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data.viewWidth, true,
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cells, records, nodes,
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this._itmTmp.viewContainer,
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this._itmTmp.templateRef,
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this._hdrTmp && this._hdrTmp.templateRef,
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@ -477,56 +479,93 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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// ******** DOM WRITE ****************
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this._cd.detectChanges();
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// at this point, this fn was called from within another
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// requestAnimationFrame, so the next dom reads/writes within the next frame
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// wait a frame before trying to read and calculate the dimensions
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nativeRaf(this.postRenderVirtual.bind(this));
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}
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this._dom.read(() => {
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// ******** DOM READ ****************
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initReadNodes(nodes, cells, data);
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});
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/**
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* @private
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* DOM READ THEN DOM WRITE
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*/
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postRenderVirtual() {
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// ******** DOM READ THEN DOM WRITE ****************
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initReadNodes(this._nodes, this._cells, this._data);
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this._dom.write(() => {
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const ele = this._elementRef.nativeElement;
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const recordsLength = records.length;
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const renderer = this._renderer;
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// update the bound context for each node
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updateNodeContext(nodes, cells, data);
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// ******** DOM READS ABOVE / DOM WRITES BELOW ****************
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// ******** DOM WRITE ****************
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this._renderer.setElementClass(this._elementRef.nativeElement, 'virtual-scroll', true);
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// ******** DOM WRITE ****************
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writeToNodes(this._nodes, this._cells, this._records.length);
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// ******** DOM WRITE ****************
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this.setVirtualHeight(
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estimateHeight(this._records.length, this._cells[this._cells.length - 1], this._vHeight, 0.25)
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);
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}
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/**
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* @private
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*/
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scrollUpdate() {
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clearNativeTimeout(this._tmId);
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this._tmId = nativeTimeout(this.onScrollEnd.bind(this), SCROLL_END_TIMEOUT_MS);
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let data = this._data;
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if (this._queue === QUEUE_CHANGE_DETECTION) {
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// ******** DOM WRITE ****************
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this._cd.detectChanges();
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// add an element at the end so :last-child css doesn't get messed up
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// ******** DOM WRITE ****************
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writeToNodes(this._nodes, this._cells, this._records.length);
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const lastEle: HTMLElement = renderer.createElement(ele, 'div');
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lastEle.className = 'virtual-last';
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// ******** DOM WRITE ****************
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renderer.setElementClass(ele, 'virtual-scroll', true);
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// ******** DOM WRITE ****************
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renderer.setElementClass(ele, 'virtual-loading', false);
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// ******** DOM WRITE ****************
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writeToNodes(nodes, cells, recordsLength);
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// ******** DOM WRITE ****************
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this.setVirtualHeight(
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estimateHeight(this._records.length, this._cells[this._cells.length - 1], this._vHeight, 0.25)
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estimateHeight(recordsLength, cells[cells.length - 1], this._vHeight, 0.25)
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);
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this._queue = null;
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this._content.imgsRefresh();
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});
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}
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/**
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* @private
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*/
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scrollUpdate(ev: ScrollEvent) {
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// there is a queue system so that we can
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// spread out the work over multiple frames
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const data = this._data;
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const cells = this._cells;
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const nodes = this._nodes;
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// set the scroll top from the scroll event
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data.scrollTop = ev.scrollTop;
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if (this._queue === ScrollQueue.RequiresDomWrite) {
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this._dom.write(() => {
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// ******** DOM WRITE ****************
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writeToNodes(nodes, cells, this._records.length);
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// ******** DOM WRITE ****************
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this.setVirtualHeight(
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estimateHeight(this._records.length, cells[cells.length - 1], this._vHeight, 0.25)
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);
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// we're done here, good work
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this._queue = ScrollQueue.NoChanges;
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});
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} else if (this._queue === ScrollQueue.RequiresChangeDetection) {
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this._dom.write(() => {
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// we've got work painting do, let's throw it in the
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// domWrite callback so everyone plays nice
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// ******** DOM WRITE ****************
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for (var i = 0; i < nodes.length; i++) {
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if (nodes[i].hasChanges) {
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(<any>nodes[i].view).detectChanges();
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}
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}
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// on the next frame we need write to the dom nodes manually
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this._queue = ScrollQueue.RequiresDomWrite;
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});
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} else {
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@ -538,36 +577,31 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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if (data.scrollDiff > 0) {
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// load data we may not have processed yet
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let stopAtHeight = (data.scrollTop + data.renderHeight);
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var stopAtHeight = (data.scrollTop + data.renderHeight);
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processRecords(stopAtHeight, this._records, this._cells,
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processRecords(stopAtHeight, this._records, cells,
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this._hdrFn, this._ftrFn, data);
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}
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// ******** DOM READ ****************
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updateDimensions(this._nodes, this._cells, data, false);
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updateDimensions(nodes, cells, data, false);
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adjustRendered(this._cells, data);
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adjustRendered(cells, data);
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let madeChanges = populateNodeData(data.topCell, data.bottomCell,
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data.viewWidth, data.scrollDiff > 0,
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this._cells, this._records, this._nodes,
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this._itmTmp.viewContainer,
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this._itmTmp.templateRef,
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this._hdrTmp && this._hdrTmp.templateRef,
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this._ftrTmp && this._ftrTmp.templateRef, false);
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if (madeChanges) {
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// do not update images while scrolling
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this._imgs.forEach(img => {
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img.enable(false);
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});
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var hasChanges = populateNodeData(data.topCell, data.bottomCell,
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data.viewWidth, data.scrollDiff > 0,
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cells, this._records, nodes,
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this._itmTmp.viewContainer,
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this._itmTmp.templateRef,
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this._hdrTmp && this._hdrTmp.templateRef,
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this._ftrTmp && this._ftrTmp.templateRef, false);
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if (hasChanges) {
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// queue making updates in the next frame
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this._queue = QUEUE_CHANGE_DETECTION;
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this._queue = ScrollQueue.RequiresChangeDetection;
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} else {
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this._queue = null;
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// update the bound context for each node
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updateNodeContext(nodes, cells, data);
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}
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}
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@ -578,24 +612,35 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
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* @private
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* DOM WRITE
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*/
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onScrollEnd() {
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// scrolling is done, allow images to be updated now
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this._imgs.forEach(img => {
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img.enable(true);
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});
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scrollEnd(ev: ScrollEvent) {
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const nodes = this._nodes;
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const cells = this._cells;
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const data = this._data;
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// ******** DOM READ ****************
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updateDimensions(this._nodes, this._cells, this._data, false);
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updateDimensions(nodes, cells, data, false);
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adjustRendered(this._cells, this._data);
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adjustRendered(cells, data);
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// ******** DOM WRITE ****************
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this._cd.detectChanges();
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// ******** DOM READS ABOVE / DOM WRITES BELOW ****************
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// ******** DOM WRITE ****************
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this.setVirtualHeight(
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estimateHeight(this._records.length, this._cells[this._cells.length - 1], this._vHeight, 0.05)
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);
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this._dom.write(() => {
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// update the bound context for each node
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updateNodeContext(nodes, cells, data);
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// ******** DOM WRITE ****************
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this._cd.detectChanges();
|
||||
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||||
// ******** DOM WRITE ****************
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||||
writeToNodes(nodes, cells, this._records.length);
|
||||
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||||
// ******** DOM WRITE ****************
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||||
this.setVirtualHeight(
|
||||
estimateHeight(this._records.length, cells[cells.length - 1], this._vHeight, 0.05)
|
||||
);
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||||
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this._queue = ScrollQueue.NoChanges;
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||||
});
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||||
}
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||||
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/**
|
||||
@ -616,34 +661,22 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
|
||||
* @private
|
||||
* NO DOM
|
||||
*/
|
||||
addScrollListener() {
|
||||
let self = this;
|
||||
|
||||
if (!self._unreg) {
|
||||
self._zone.runOutsideAngular(() => {
|
||||
|
||||
function onScroll() {
|
||||
// ******** DOM READ ****************
|
||||
self._data.scrollTop = self._content.getScrollTop();
|
||||
|
||||
// ******** DOM READ THEN DOM WRITE ****************
|
||||
self.scrollUpdate();
|
||||
}
|
||||
|
||||
if (self._eventAssist) {
|
||||
// use JS scrolling for iOS UIWebView
|
||||
// goal is to completely remove this when iOS
|
||||
// fully supports scroll events
|
||||
// listen to JS scroll events
|
||||
self._unreg = self._content.jsScroll(onScroll);
|
||||
|
||||
} else {
|
||||
// listen to native scroll events
|
||||
self._unreg = self._content.addScrollListener(onScroll);
|
||||
}
|
||||
|
||||
});
|
||||
addScrollListener(eventAssist: boolean) {
|
||||
if (eventAssist) {
|
||||
// use JS scrolling for iOS UIWebView
|
||||
// goal is to completely remove this when iOS
|
||||
// fully supports scroll events
|
||||
// listen to JS scroll events
|
||||
this._content.enableJsScroll();
|
||||
}
|
||||
|
||||
this._scrollSub = this._content.ionScroll.subscribe((ev: ScrollEvent) => {
|
||||
this.scrollUpdate(ev);
|
||||
});
|
||||
|
||||
this._scrollEndSub = this._content.ionScrollEnd.subscribe((ev: ScrollEvent) => {
|
||||
this.scrollEnd(ev);
|
||||
});
|
||||
}
|
||||
|
||||
/**
|
||||
@ -651,12 +684,16 @@ export class VirtualScroll implements DoCheck, AfterContentInit, OnDestroy {
|
||||
* NO DOM
|
||||
*/
|
||||
ngOnDestroy() {
|
||||
this._unreg && this._unreg();
|
||||
this._unreg = null;
|
||||
this._scrollSub && this._scrollSub.unsubscribe();
|
||||
this._scrollEndSub && this._scrollEndSub.unsubscribe();
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
const SCROLL_END_TIMEOUT_MS = 140;
|
||||
const SCROLL_DIFFERENCE_MINIMUM = 20;
|
||||
const QUEUE_CHANGE_DETECTION = 0;
|
||||
|
||||
export const enum ScrollQueue {
|
||||
NoChanges,
|
||||
RequiresChangeDetection,
|
||||
RequiresDomWrite
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user