Q: GWT CellList Click to Toggle selection (Multi-Selection) I'd like to setup a CellList so that clicking a row will toggle the selection. Such that multiple rows can be selected with out the need for holding the ctrl key.
What do I need to change to get it working?
class ToggleEventTranslator<T> implements DefaultSelectionEventManager.EventTranslator<T> {
    @Override
    public boolean clearCurrentSelection(final CellPreviewEvent<T> event) {
        return false;
    }

    @Override
    public SelectAction translateSelectionEvent(final CellPreviewEvent<T> event) {
        return SelectAction.TOGGLE;
    }

}


MultiSelectionModel<ObjProxy> multiSelectionModel = new MultiSelectionModel<ObjProxy>();

    ocjCellList.setSelectionModel(multiSelectionModel, DefaultSelectionEventManager
            .<ObjProxy> createCustomManager(new ToggleEventTranslator<ObjProxy>()));


A: list.addCellPreviewHandler(new Handler<T>() {

        @Override
        public void onCellPreview(final CellPreviewEvent<T> event) {

            if (BrowserEvents.CLICK.equals(event.getNativeEvent().getType())) {

                final T value = event.getValue();
                final Boolean state = !event.getDisplay().getSelectionModel().isSelected(value);
                event.getDisplay().getSelectionModel().setSelected(value, state);
                event.setCanceled(true);
            }
        }
});


private final MultiSelectionModel<T> selectModel = new MultiSelectionModel<T>();

final Handler<T> selectionEventManager = DefaultSelectionEventManager.createCheckboxManager();
list.setSelectionModel(selectModel, selectionEventManager);


A: "Whether you add a checkbox column or not, you'll have to add a cell preview handler. The easiest way to define one is to use DefaultSelectionEventManager, either using a checkbox manager in combination with a checkbox column, or creating a custom one (you'd map a click event into a toggle action).
You can see it used, the checkbox variant, in the GWT Showcase; it uses the setSelectionModel overload with two arguments to add the CellPreviewEvent.Handler at the same time."
(Credit to this answer)
