public void setSteppingSource(final boolean isSteppingSource) {
        this.isSteppingSource = isSteppingSource;
        // Allowing hex view while stepping is fiddly so not doing it for now. The hex view has totally
        // different line/col for the same source byte, so position and highlights need to be translated
        // into hex dump terms.
        textPresenter.getViewAsHexOption().setAvailable(!isSteppingSource);
    }
Will attempt to set the source range using the passed highlight, i.e. if the highlight
is towards the end of the data then it will set the range to enclose the highlight.
stroom-core-client/src/main/java/stroom/data/client/presenter/SourcePresenter.java