<div id="editor">
<p>This editor is read-only.</p>
</div>

<button id="toggle">Toggle read-only mode</button>

<script>
exportPdfUtils.initManualTest();

var editor = CKEDITOR.replace( 'editor', exportPdfUtils.getDefaultConfig( 'manual', {
readOnly: true
} ) );

CKEDITOR.document.getById( 'toggle' ).on( 'click', function() {
editor.setReadOnly( !editor.readOnly );
} );
</script>