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| /*
* @license
* Copyright Hôpitaux Universitaires de Genève. All Rights Reserved.
*
* Use of this source code is governed by an Apache-2.0 license that can be
* found in the LICENSE file at https://github.com/DSI-HUG/dejajs-components/blob/master/LICENSE
*/
import { Injectable, OnDestroy } from '@angular/core';
import { BehaviorSubject, combineLatest as observableCombineLatest, from as observableFrom, Observable, of as observableOf, ReplaySubject, Subscription, timer as observableTimer } from 'rxjs';
import { combineLatest, debounceTime, distinctUntilChanged, filter, map, switchMap, tap } from 'rxjs/operators';
import { IViewPort, IViewPortItem } from './viewport.service';
export enum ViewportMode {
disabled,
fixed,
variable,
auto,
}
export enum ViewportDirection {
vertical,
horizontal,
}
/** Service de gestion du viewport d'une liste.
* Ce service permet la gestion du viewport verticalement ou horizontalement.
*/
@Injectable()
export class ViewPortService implements OnDestroy {
public static itemDefaultSize = 40;
public viewPort$: Observable<IViewPort>;
public mode$ = new BehaviorSubject<ViewportMode | string>(ViewportMode.fixed);
public items$ = new BehaviorSubject<IViewPortItem[]>([]);
public maxSize$ = new BehaviorSubject<number | string>(0);
public ensureItem$ = new BehaviorSubject<IViewPortItem | number>(null);
public scrollPosition$ = new BehaviorSubject<number>(0);
public element$ = new ReplaySubject<HTMLElement>(1);
public itemsSize$ = new BehaviorSubject<number>(0);
public direction$ = new BehaviorSubject<ViewportDirection | string>(ViewportDirection.vertical);
public ensureParams$: Observable<IEnsureParams>;
private subscriptions = [] as Subscription[];
private refresh$ = new BehaviorSubject<IViewPortRefreshParams>(null);
private deleteSizeCache$ = new BehaviorSubject<boolean>(true);
private lastCalculatedSize: number;
private emptyViewPort = {
beforeSize: 0,
afterSize: 0,
viewPortSize: 0,
listSize: 0,
visibleItems: [],
startIndex: 0,
endIndex: 0,
scrollPos: 0,
items: [],
} as IViewPort;
private measureViewPort = {
beforeSize: 0,
afterSize: 200000,
viewPortSize: 0,
listSize: 0,
visibleItems: [],
startIndex: 0,
endIndex: 0,
scrollPos: undefined, // Do not change the scroll pos in case of refresh is called when the list is scrolling (I.E. dynamic content loading)
items: [],
} as IViewPort;
public viewPortResult$ = new BehaviorSubject<IViewPort>(this.emptyViewPort);
private _mode: ViewportMode = ViewportMode.fixed;
private _itemsSize = ViewPortService.itemDefaultSize;
private _direction = ViewportDirection.vertical;
private _scrollPosition = 0;
private viewPort: IViewPort;
private ignoreScrollCount = 0;
public get mode() {
return this._mode;
}
public get itemsSize() {
return this._itemsSize;
}
public get direction() {
return this._direction;
}
constructor() {
this.viewPort$ = observableFrom(this.viewPortResult$);
// const consoleLog = (_message: string) => {
// // console.log(_message);
// };
const innerSize = () => {
return this._direction === ViewportDirection.horizontal ? window.innerWidth : window.innerHeight;
};
const clientSize = (element: HTMLElement) => {
return Math.ceil(this._direction === ViewportDirection.horizontal ? element.clientWidth : element.clientHeight);
};
const calcFixedSizeViewPort$ = (items: IViewPortItem[], containerSize: number, scrollPos: number, itemDefaultSize: number, ensureParams: IEnsureParams): Observable<IViewPort> => {
// consoleLog(`calcFixedSizeViewPort`);
const maxCount = Math.ceil(containerSize / itemDefaultSize) + 1;
const startRow = Math.floor(scrollPos / itemDefaultSize);
const rowsCount = Math.min(items.length - startRow, maxCount);
let startIndex: number;
let endIndex: number;
let newScrollPos: number;
if (!ensureParams || ensureParams.index === undefined || !ensureParams.atEnd) {
if (rowsCount < 0) {
endIndex = items.length - 1;
startIndex = endIndex + 1 - Math.min(items.length, maxCount);
} else if (ensureParams.index !== undefined) {
startIndex = ensureParams.index;
endIndex = startIndex + rowsCount - 1;
newScrollPos = startIndex * itemDefaultSize;
} else {
startIndex = startRow;
endIndex = startIndex + rowsCount - 1;
}
} else {
// Ensure visible from the end
startIndex = Math.max(0, ensureParams.index + 1 - Math.min(items.length, maxCount));
endIndex = Math.max(ensureParams.index, rowsCount - 1);
newScrollPos = (endIndex + 1) * itemDefaultSize - containerSize;
}
const visibleItems = items.slice(startIndex, endIndex + 1);
return observableOf({
beforeSize: startIndex * itemDefaultSize,
afterSize: (items.length - endIndex - 1) * itemDefaultSize,
listSize: containerSize,
viewPortSize: visibleItems.length * itemDefaultSize,
visibleItems: visibleItems,
startIndex: startIndex,
endIndex: endIndex,
scrollPos: newScrollPos,
items: items,
} as IViewPort);
};
const calcVariableSizeViewPort$ = (items: IViewPortItem[], containerSize: number, scrollPos: number, itemDefaultSize: number, ensureParams: IEnsureParams): Observable<IViewPort> => {
// consoleLog(`calcVariableSizeViewPort`);
const visibleList = [] as IViewPortItem[];
let startIndex: number;
let endIndex: number;
let beforeSize = 0;
let viewPortSize = 0;
let afterSize = 0;
let newScrollPos: number;
if (!ensureParams || ensureParams.index === undefined || !ensureParams.atEnd) {
items.forEach((item: IViewPortItem, index: number) => {
const itemSize = item.size || itemDefaultSize;
if (ensureParams && ensureParams.index === index) {
startIndex = index;
newScrollPos = beforeSize;
}
if (startIndex === undefined) {
if (beforeSize + itemSize >= scrollPos) {
startIndex = index;
} else {
beforeSize += itemSize;
}
}
if (startIndex !== undefined && endIndex === undefined) {
viewPortSize += itemSize;
visibleList.push(item);
}
if (endIndex === undefined) {
if ((beforeSize + viewPortSize > (newScrollPos || scrollPos) + containerSize) || index === items.length - 1) {
endIndex = index;
}
} else {
afterSize += itemSize;
}
});
} else {
// Ensure visible from the end
let index = items.length;
while (--index >= 0) {
const item = items[index];
const itemSize = item.size || itemDefaultSize;
if (ensureParams.index === index) {
endIndex = index;
}
if (endIndex !== undefined) {
if (startIndex === undefined) {
viewPortSize += itemSize;
visibleList.unshift(item);
if (viewPortSize > containerSize || index === 0) {
startIndex = index;
newScrollPos = viewPortSize - containerSize;
}
} else {
newScrollPos += itemSize;
beforeSize += itemSize;
}
} else {
afterSize += itemSize;
}
}
}
Iif (ensureParams && ensureParams.index !== undefined && viewPortSize < containerSize && visibleList.length < items.length) {
if (ensureParams.atEnd) {
return calcVariableSizeViewPort$(items, containerSize, scrollPos, itemDefaultSize, {
index: 0,
atEnd: false,
} as IEnsureParams);
} else {
return calcVariableSizeViewPort$(items, containerSize, scrollPos, itemDefaultSize, {
index: items.length - 1,
atEnd: true,
} as IEnsureParams);
}
}
return observableOf({
beforeSize: beforeSize,
afterSize: afterSize,
listSize: containerSize,
viewPortSize: viewPortSize,
visibleItems: visibleList,
startIndex: startIndex || 0,
endIndex: endIndex,
scrollPos: newScrollPos,
items: items,
} as IViewPort);
};
const calcAutoSizeViewPort$ = (items: IViewPortItem[], containerSize: number, scrollPos: number, element: HTMLElement, itemDefaultSize: number, ensureParams: IEnsureParams, isCalculation?: boolean): Observable<IViewPort> => {
// consoleLog(`calcAutoSizeViewPort`);
return calcVariableSizeViewPort$(items, containerSize, scrollPos, itemDefaultSize, ensureParams).pipe(
switchMap((viewPort: IViewPort) => {
const calculationRequired = !isCalculation && viewPort.visibleItems.find((item) => !item.size);
Iif (!calculationRequired) {
return observableOf(viewPort);
} else {
// Measure items size
this.viewPortResult$.next(viewPort);
return observableTimer(1).pipe(
tap(() => {
const elements = element.getElementsByClassName('listitem');
// tslint:disable-next-line:prefer-for-of
for (let i = 0; i < elements.length; i++) {
const itemElement = elements[i] as HTMLElement;
const index = +itemElement.getAttribute('flat');
const item = viewPort.visibleItems[index - viewPort.startIndex];
if (item) {
item.size = clientSize(itemElement);
}
}
// Recalc Viewport size
viewPort.viewPortSize = viewPort.visibleItems.reduce((size, item) => size += item.size || itemDefaultSize, 0);
}),
switchMap(() => calcVariableSizeViewPort$(items, containerSize, viewPort.scrollPos || scrollPos, itemDefaultSize, ensureParams)));
}
}));
};
const calcDisabledViewPort$ = (items: IViewPortItem[], containerSize: number, scrollPos: number, element: HTMLElement, ensureParams: IEnsureParams, bindIfAny: boolean): Observable<IViewPort> => {
let viewPortSize = 0;
let startIndex: number;
let endIndex: number;
let newScrollPos: number;
const elements = element.getElementsByClassName('listitem');
let viewPort = {
beforeSize: 0,
afterSize: 0,
listSize: containerSize,
viewPortSize: 0,
visibleItems: [],
startIndex: 0,
endIndex: 0,
scrollPos: 0,
items: items,
} as IViewPort;
Iif (elements.length !== items.length && bindIfAny !== false) {
this.viewPortResult$.next(viewPort);
return observableTimer(1).pipe(
switchMap(() => calcDisabledViewPort$(items, containerSize, scrollPos, element, ensureParams, false)));
}
Eif (!ensureParams || ensureParams.index === undefined || !ensureParams.atEnd) {
for (let i = 0; i < elements.length; i++) {
const itemElement = elements[i] as HTMLElement;
const itemSize = items[i].size = clientSize(itemElement);
Iif (ensureParams && ensureParams.index === i) {
startIndex = i;
newScrollPos = viewPortSize;
}
viewPortSize += itemSize;
if (startIndex === undefined && viewPortSize > scrollPos) {
startIndex = i;
}
if (endIndex === undefined && viewPortSize > (newScrollPos || scrollPos) + containerSize) {
endIndex = i;
}
}
} else {
// Ensure visible from the end
newScrollPos = 0;
let listSize = 0;
let i = elements.length;
while (--i >= 0) {
const itemElement = elements[i] as HTMLElement;
const itemSize = items[i].size = clientSize(itemElement);
if (ensureParams.index === i) {
endIndex = i;
}
if (endIndex !== undefined) {
if (startIndex === undefined) {
listSize += itemSize;
if (listSize > containerSize) {
startIndex = i;
newScrollPos = listSize - containerSize;
}
} else {
newScrollPos += itemSize;
}
}
viewPortSize += itemSize;
}
}
startIndex = startIndex || 0;
endIndex = endIndex || 0;
// consoleLog(`viewPortSize ${viewPortSize}`);
viewPort = {
beforeSize: 0,
afterSize: 0,
listSize: containerSize,
viewPortSize: viewPortSize,
visibleItems: items.slice(startIndex, 1 + endIndex),
startIndex: startIndex,
endIndex: endIndex,
scrollPos: newScrollPos,
items: items,
} as IViewPort;
return observableOf(viewPort);
};
const calcViewPort$: any = (items: IViewPortItem[], maxSize: number, scrollPos: number, element: HTMLElement, itemDefaultSize: number, ensureParams: IEnsureParams, fromMeasure?: boolean) => {
// consoleLog(`calcViewPort`);
if (!items || !items.length) {
return observableOf(this.emptyViewPort);
}
let listSize = maxSize || clientSize(element);
if (listSize <= ViewPortService.itemDefaultSize) {
listSize = innerSize();
}
return observableOf(this.mode).pipe(
switchMap((mode) => {
if (ensureParams.index !== undefined) {
this.ignoreScrollCount++;
} else {
this.ignoreScrollCount = 0;
}
switch (mode) {
case ViewportMode.disabled:
return calcDisabledViewPort$(items, listSize, scrollPos, element, ensureParams, true);
case ViewportMode.variable:
return calcVariableSizeViewPort$(items, listSize, scrollPos, itemDefaultSize, ensureParams);
case ViewportMode.auto:
return calcAutoSizeViewPort$(items, listSize, scrollPos, element, itemDefaultSize, ensureParams);
case ViewportMode.fixed:
return calcFixedSizeViewPort$(items, listSize, scrollPos, itemDefaultSize, ensureParams);
default:
throw new Error('ViewPortService, invalide mode. The value can be disabled, variable, auto and fixed.');
}
}),
switchMap((viewPort: IViewPort) => {
if (!fromMeasure) {
const endScrollPos = viewPort.beforeSize + viewPort.viewPortSize + viewPort.afterSize - viewPort.listSize;
if (this.mode !== ViewportMode.disabled && listSize < 2 * ViewPortService.itemDefaultSize) {
// Measure again container and recalc viewport
this.viewPortResult$.next(this.measureViewPort);
return observableTimer(1).pipe(switchMap(() => calcViewPort$(items, maxSize, scrollPos, element, itemDefaultSize, ensureParams, true)));
} else if (endScrollPos < 0 || (items.length && endScrollPos > 0 && (viewPort.scrollPos || scrollPos) > endScrollPos)) {
// Scroll position is over the last item
// Ensure last item visible and recalc viewport
return calcViewPort$(items, maxSize, 0, element, itemDefaultSize, {
index: items.length - 1,
atEnd: true,
} as IEnsureParams, true);
} else Iif (this.mode === ViewportMode.auto && viewPort.viewPortSize < listSize) {
// Rendered viewport is to small, render again to complete
return calcViewPort$(items, maxSize, 0, element, itemDefaultSize, {
index: items.length - 1,
atEnd: true,
} as IEnsureParams, true);
}
}
// Return calculated viewport
return observableOf(viewPort);
}),
tap(() => {
// consoleLog(`clear ensureParams ${ensureParams && ensureParams.index}`);
ensureParams.index = undefined;
}));
};
const items$ = observableFrom(this.items$);
// .do(() => consoleLog('items'));
// Ensure item visible by index or instance
this.ensureParams$ = observableCombineLatest(this.ensureItem$, items$).pipe(
map(([ensureItem, items]) => {
this.ignoreScrollCount = 0;
const ensureParams = {} as IEnsureParams;
if (ensureItem !== undefined && ensureItem !== null && items && items.length) {
let ensureIndex = ensureItem as number;
if (isNaN(ensureIndex)) {
ensureIndex = items.findIndex((itm) => ensureItem === itm);
}
Eif (ensureIndex >= 0) {
if (this.viewPort && ensureIndex <= this.viewPort.startIndex) {
ensureParams.index = ensureIndex;
ensureParams.atEnd = false;
} else if (!this.viewPort || ensureIndex >= this.viewPort.endIndex) {
ensureParams.index = ensureIndex;
ensureParams.atEnd = true;
}
}
}
return ensureParams;
}));
// .do((ensureParams) => consoleLog(`ensureParams index:${ensureParams && ensureParams.index} atEnd:${ensureParams && ensureParams.atEnd}`));
const maxSize$ = observableFrom(this.maxSize$).pipe(
distinctUntilChanged());
// .do((value) => consoleLog(`maxSize ${value}`));
const refresh$ = observableFrom(this.refresh$).pipe(
switchMap((params: IViewPortRefreshParams) => {
this.ignoreScrollCount = 0;
if (params) {
Iif (params.clearMeasuredSize) {
return observableFrom(this.items$).pipe(
tap((items) => {
this.lastCalculatedSize = undefined;
items.forEach((item) => item.size = undefined);
}),
map(() => params));
}
Iif (params.items) {
params.items.forEach((item) => item.size = undefined);
}
}
return observableOf(params);
}));
// .do(() => consoleLog('refresh'));
const scrollPos$ = observableFrom(this.scrollPosition$).pipe(
map((scrollPos) => this._scrollPosition = scrollPos || 0),
map((scrollPos) => Math.max(scrollPos, 0)),
filter(() => {
if (this.ignoreScrollCount > 0) {
this.ignoreScrollCount--;
// consoleLog(`ignoreScrollCount ${this.ignoreScrollCount}`);
return false;
} else {
return true;
}
}),
distinctUntilChanged());
// .do((value) => consoleLog(`scrollPos ${value}`));
const mode$ = observableFrom(this.mode$).pipe(
map((mode) => {
this._mode = typeof mode === 'string' ? (<any>ViewportMode)[mode] : mode;
return this._mode;
}),
distinctUntilChanged());
// .do((value) => consoleLog(`mode ${value}`));
const direction$ = observableFrom(this.direction$).pipe(
map((direction) => {
this._direction = typeof direction === 'string' ? (<any>ViewportDirection)[direction] : direction;
return this._direction;
}),
distinctUntilChanged());
// .do((value) => consoleLog(`direction ${value}`));
const itemsSize$ = observableFrom(this.itemsSize$).pipe(
distinctUntilChanged(),
tap((value) => this._itemsSize = value));
// .do((value) => consoleLog(`itemsSize ${value}`));
const element$ = observableFrom(this.element$).pipe(
tap((element) => {
if (!element) {
this.viewPort = undefined;
this.ignoreScrollCount = 0;
this.lastCalculatedSize = undefined;
}
}));
// .do(() => consoleLog(`element`));
// Reset items size when direction change in auto mode
this.subscriptions.push(observableCombineLatest(direction$, items$, mode$, this.deleteSizeCache$).pipe(
filter(([_direction, items, mode]) => items && items.length && mode === ViewportMode.auto),
switchMap(([_direction, items]) => items))
.subscribe((item) => {
item.size = undefined;
}));
// Calc view port observable
this.subscriptions.push(observableCombineLatest(element$, items$, refresh$, this.ensureParams$).pipe(
combineLatest(direction$, mode$, itemsSize$, maxSize$),
debounceTime(1),
combineLatest(scrollPos$),
filter(([[[element]]]) => !!element),
// .do(([[[_element, _items, _refresh, ensureParams], _direction, _mode, _itemDefaultSize, _maxSize], _scrollPos]) => consoleLog(`combineLatest ${JSON.stringify(ensureParams)}`))
switchMap(([[[element, items, _refresh, ensureParams], _direction, _mode, itemDefaultSize, maxSize], _scrollPos]) => {
// consoleLog(`combineLatest ${ensureParams && ensureParams.index}`);
if (!itemDefaultSize) {
itemDefaultSize = ViewPortService.itemDefaultSize;
}
const listSize = this.lastCalculatedSize || maxSize || clientSize(element);
const scrollPos = this._scrollPosition;
let maxSizeValue = maxSize === 'auto' ? 0 : +maxSize;
if (items && items.length && (listSize === 'auto' || listSize < 2 * ViewPortService.itemDefaultSize)) {
// Set the viewlist to the maximum height to measure the real max-height defined in the css
// Use a blank div to do that
// consoleLog(`viewPortResult for measure ${JSON.stringify(this.measureViewPort)}`);
this.viewPortResult$.next(this.measureViewPort);
// Wait next life cycle for the result
return observableTimer(1).pipe(
map(() => {
// Get mx size from container
maxSizeValue = this.lastCalculatedSize = clientSize(element);
// Ensure that max size is not more than the items size
if (this.mode === ViewportMode.fixed) {
Iif (items.length * itemDefaultSize < maxSizeValue) {
maxSizeValue = items.length * itemDefaultSize;
}
} else Eif (this.mode === ViewportMode.variable) {
let maxItemsSize = 0;
items.find((item) => {
maxItemsSize += item.size || itemDefaultSize;
return maxItemsSize > maxSizeValue;
});
Iif (maxItemsSize < maxSizeValue) {
maxSizeValue = maxItemsSize;
}
} else if (this.mode === ViewportMode.auto) {
}
return { element, scrollPos, items, maxSizeValue, itemDefaultSize, ensureParams };
}));
} else {
maxSizeValue = maxSizeValue || this.lastCalculatedSize;
return observableOf({ element, scrollPos, items, maxSizeValue, itemDefaultSize, ensureParams });
}
}),
switchMap(({ element, scrollPos, items, maxSizeValue, itemDefaultSize, ensureParams }) => {
// consoleLog(`calcViewPort ${ensureParams && ensureParams.index}`);
return calcViewPort$(items, maxSizeValue, scrollPos, element, itemDefaultSize, ensureParams);
}))
.subscribe((viewPort: IViewPort) => {
// consoleLog(`viewPortResult final ${JSON.stringify(viewPort)}`);
this.viewPortResult$.next(viewPort);
}, ((error) => {
console.error(error);
})));
// Cache last calculated viewport
this.subscriptions.push(observableFrom(this.viewPortResult$).subscribe((viewPort: IViewPort) => this.viewPort = viewPort));
}
public ngOnDestroy() {
this.subscriptions.forEach((subscription: Subscription) => subscription.unsubscribe());
}
public deleteSizeCache() {
this.deleteSizeCache$.next(true);
}
public clear() {
this.viewPortResult$.next(this.emptyViewPort);
}
public refresh(params?: IViewPortRefreshParams) {
this.refresh$.next(params || null);
}
}
export interface IEnsureParams {
index: number;
atEnd: boolean;
}
export interface IViewPort {
beforeSize: number;
afterSize: number;
visibleItems: IViewPortItem[];
startIndex: number;
endIndex: number;
viewPortSize: number;
listSize: number;
scrollPos: number;
items: IViewPortItem[];
}
export interface IViewPortItem { size?: number; }
export interface IViewPortRefreshParams {
items: IViewPortItem[];
clearMeasuredSize: boolean;
}
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