ব্যবহারকারী স্ক্রোল আপ করার চেষ্টা করেছিল কিনা তা দেখার জন্য আমি একটি চেক যোগ করেছি।
কেউ চাইলে আমি এই এখানেই রেখে যাব :)
<div class="jumbotron">
<div class="messages-box" #scrollMe (scroll)="onScroll()">
<app-message [message]="message" [userId]="profile.userId" *ngFor="let message of messages.slice().reverse()"></app-message>
</div>
<textarea [(ngModel)]="newMessage" (keyup.enter)="submitMessage()"></textarea>
</div>
এবং কোড:
import { AfterViewChecked, ElementRef, ViewChild, Component, OnInit } from '@angular/core';
import {AuthService} from "../auth.service";
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/switchMap';
import 'rxjs/add/operator/concatAll';
import {Observable} from 'rxjs/Rx';
import { Router, ActivatedRoute } from '@angular/router';
@Component({
selector: 'app-messages',
templateUrl: './messages.component.html',
styleUrls: ['./messages.component.scss']
})
export class MessagesComponent implements OnInit {
@ViewChild('scrollMe') private myScrollContainer: ElementRef;
messages:Array<MessageModel>
newMessage = ''
id = ''
conversations: Array<ConversationModel>
profile: ViewMyProfileModel
disableScrollDown = false
constructor(private authService:AuthService,
private route:ActivatedRoute,
private router:Router,
private conversationsApi:ConversationsApi) {
}
ngOnInit() {
}
public submitMessage() {
}
ngAfterViewChecked() {
this.scrollToBottom();
}
private onScroll() {
let element = this.myScrollContainer.nativeElement
let atBottom = element.scrollHeight - element.scrollTop === element.clientHeight
if (this.disableScrollDown && atBottom) {
this.disableScrollDown = false
} else {
this.disableScrollDown = true
}
}
private scrollToBottom(): void {
if (this.disableScrollDown) {
return
}
try {
this.myScrollContainer.nativeElement.scrollTop = this.myScrollContainer.nativeElement.scrollHeight;
} catch(err) { }
}
}