ng-zorro-antd/fesm2015/ng-zorro-antd-back-top.js

An enterprise-class UI components based on Ant Design and Angular

import { Platform } from '@angular/cdk/platform';
import { fromEvent } from 'rxjs';
import { distinctUntilChanged, throttleTime } from 'rxjs/operators';
import { DOCUMENT, CommonModule } from '@angular/common';
import { ChangeDetectionStrategy, ChangeDetectorRef, Component, EventEmitter, Inject, Input, Output, ViewEncapsulation, NgModule } from '@angular/core';
import { fadeMotion, toNumber, NzScrollService, SCROLL_SERVICE_PROVIDER } from 'ng-zorro-antd/core';

/**
 * @fileoverview added by tsickle
 * @suppress {checkTypes,extraRequire,missingOverride,missingReturn,unusedPrivateMembers,uselessCode} checked by tsc
 */
class NzBackTopComponent {
    /**
     * @param {?} scrollSrv
     * @param {?} doc
     * @param {?} platform
     * @param {?} cd
     */
    constructor(scrollSrv, doc, platform, cd) {
        this.scrollSrv = scrollSrv;
        this.doc = doc;
        this.platform = platform;
        this.cd = cd;
        this.scroll$ = null;
        this.target = null;
        this.visible = false;
        this._visibilityHeight = 400;
        this.nzClick = new EventEmitter();
    }
    /**
     * @param {?} value
     * @return {?}
     */
    set nzVisibilityHeight(value) {
        this._visibilityHeight = toNumber(value, 400);
    }
    /**
     * @return {?}
     */
    get nzVisibilityHeight() {
        return this._visibilityHeight;
    }
    /**
     * @param {?} el
     * @return {?}
     */
    set nzTarget(el) {
        this.target = typeof el === 'string' ? this.doc.querySelector(el) : el;
        this.registerScrollEvent();
    }
    /**
     * @return {?}
     */
    ngOnInit() {
        if (!this.scroll$) {
            this.registerScrollEvent();
        }
    }
    /**
     * @return {?}
     */
    clickBackTop() {
        this.scrollSrv.scrollTo(this.getTarget(), 0);
        this.nzClick.emit(true);
    }
    /**
     * @private
     * @return {?}
     */
    getTarget() {
        return this.target || window;
    }
    /**
     * @private
     * @return {?}
     */
    handleScroll() {
        if (this.visible === this.scrollSrv.getScroll(this.getTarget()) > this.nzVisibilityHeight) {
            return;
        }
        this.visible = !this.visible;
        this.cd.markForCheck();
    }
    /**
     * @private
     * @return {?}
     */
    removeListen() {
        if (this.scroll$) {
            this.scroll$.unsubscribe();
        }
    }
    /**
     * @private
     * @return {?}
     */
    registerScrollEvent() {
        if (!this.platform.isBrowser) {
            return;
        }
        this.removeListen();
        this.handleScroll();
        this.scroll$ = fromEvent(this.getTarget(), 'scroll')
            .pipe(throttleTime(50), distinctUntilChanged())
            .subscribe((/**
         * @return {?}
         */
        () => this.handleScroll()));
    }
    /**
     * @return {?}
     */
    ngOnDestroy() {
        this.removeListen();
    }
}
NzBackTopComponent.decorators = [
    { type: Component, args: [{
                selector: 'nz-back-top',
                exportAs: 'nzBackTop',
                animations: [fadeMotion],
                template: "<div class=\"ant-back-top\" (click)=\"clickBackTop()\" @fadeMotion *ngIf=\"visible\">\n  <ng-template #defaultContent>\n    <div class=\"ant-back-top-content\">\n      <div class=\"ant-back-top-icon\"></div>\n    </div>\n  </ng-template>\n  <ng-template [ngTemplateOutlet]=\"nzTemplate || defaultContent\"></ng-template>\n</div>",
                changeDetection: ChangeDetectionStrategy.OnPush,
                encapsulation: ViewEncapsulation.None,
                preserveWhitespaces: false
            }] }
];
/** @nocollapse */
NzBackTopComponent.ctorParameters = () => [
    { type: NzScrollService },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] },
    { type: Platform },
    { type: ChangeDetectorRef }
];
NzBackTopComponent.propDecorators = {
    nzTemplate: [{ type: Input }],
    nzVisibilityHeight: [{ type: Input }],
    nzTarget: [{ type: Input }],
    nzClick: [{ type: Output }]
};

/**
 * @fileoverview added by tsickle
 * @suppress {checkTypes,extraRequire,missingOverride,missingReturn,unusedPrivateMembers,uselessCode} checked by tsc
 */
class NzBackTopModule {
}
NzBackTopModule.decorators = [
    { type: NgModule, args: [{
                declarations: [NzBackTopComponent],
                exports: [NzBackTopComponent],
                imports: [CommonModule],
                providers: [SCROLL_SERVICE_PROVIDER]
            },] }
];

/**
 * @fileoverview added by tsickle
 * @suppress {checkTypes,extraRequire,missingOverride,missingReturn,unusedPrivateMembers,uselessCode} checked by tsc
 */

/**
 * @fileoverview added by tsickle
 * @suppress {checkTypes,extraRequire,missingOverride,missingReturn,unusedPrivateMembers,uselessCode} checked by tsc
 */

export { NzBackTopComponent, NzBackTopModule };

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