interface IViewerElementContext { readonly containerElement : HTMLDivElement ; readonly viewerElement : HTMLDivElement ; } export namespace ViewerElements { export function find ( docID ) { const root = document . querySelector ( `div[data-doc-viewer-id='${ docID }']` ) ; if ( root === null ) { throw new Error ( "No root" ) ; } const containerElement = root . querySelector ( '.viewerContainer' ) ! as HTMLDivElement ; if ( containerElement === null ) { throw new Error ( "No containerElement" ) ; } const viewerElement = root . querySelector ( '.viewer' ) ! as HTMLDivElement ; if ( viewerElement === null ) { throw new Error ( "No viewerElement" ) ; } return { viewerElement , containerElement } ; } }