import { Component } from '@angular/core' ; @ Component ( { selector : 'app-demo-files-basic' , templateUrl : './basic.html' , } ) export class DemoFilesBasic { showFilename = true ; ratio = '16-by-9' ; icon = 'doctype:pdf' ; private ratios : string [ ] = [ '' , '16-by-9' , '4-by-3' , '1-by-1' ] ; changeRatio ( ) { this . ratio = this . ratios [ ( this . ratios . indexOf ( this . ratio ) + 1 ) % this . ratios . length ] ; } toggleFilename ( ) { this . showFilename = ! this . showFilename ; } }