Source: xxe/editor/ReadOnlyStateChangedEvent.js

/**
 * {@link XMLEditorEvent} sent after the read-only state of edited document 
 * has been modified (e.g. by the user using a dedicated command).
 */
export class ReadOnlyStateChangedEvent extends XMLEditorEvent {
    constructor(xmlEditor, data) {
        super(xmlEditor, data, "readOnlyStateChanged");
    }

    /**
     * Get the <code>readOnly</code> property of this event:
     * specifies whether the document being edited is read-only.
     *
     * @type {boolean}
     */
    get readOnly() {
        return this._readOnly;
    }
}