private void setDataNavigator(final boolean isViewAsHex) {
        // Only want to change the navigator if we don't already have the right one
        if (isViewAsHex
                && (dataNavigatorData == null || !NavigationMode.BYTES.equals(dataNavigatorData.getNavigationMode()))) {
            dataNavigatorData = new HexDumpNavigatorData();
            characterNavigatorPresenter.setDisplay(dataNavigatorData);
        } else if (!isViewAsHex
                && (dataNavigatorData == null || !NavigationMode.CHARS.equals(dataNavigatorData.getNavigationMode()))) {
            dataNavigatorData = new DataNavigatorData();
            characterNavigatorPresenter.setDisplay(dataNavigatorData);
        }
    }
Set how data navigation is managed.
stroom-core-client/src/main/java/stroom/data/client/presenter/SourcePresenter.java