public void enable() {
        if (!isEnabled) {
            isEnabled = true;
            StyledText textWidget = getTextWidget();
            textWidget.addPaintListener(this);
            textWidget.addLineBackgroundListener(this);
            viewerComponent.getDocument().addPositionCategory(HINT_CATEGORY);
            updater = new DefaultPositionUpdater(HINT_CATEGORY);
            viewerComponent.getDocument().addPositionUpdater(updater);
        }
    }
Activates the suggestion text painter and enables its core functionality.
plugins/org.jkiss.dbeaver.ui.editors.sql/src/org/jkiss/dbeaver/ui/editors/sql/suggestion/SQLSuggestionTextPainter.java