public Optional<DataPreviewTabPresenter> open(final SourceLocation sourceLocation, DataViewType initDataViewType,
                                                  final boolean forceOpen) {

        return super.openTabPresenter(
                forceOpen,
                new DataPreviewKey(sourceLocation),
                dataPreviewTabPresenter -> {
                    dataPreviewTabPresenter.setInitDataViewType(initDataViewType);
                    dataPreviewTabPresenter.setSourceLocation(sourceLocation);
                });

    }
4. This method will open the source and show it in the content pane.
stroom-core-client/src/main/java/stroom/data/client/DataPreviewTabPlugin.java