Define columns for selectManyCheckbox

Question

I need to show the selectManyCheckbox list in 4 columns, but the problem is that this component generates a table, so I do not have any idea of how to define the columns.

I am working with PF 3.4, I can't upgrade to PF 4.x. Do you guys have any solution for this?

EDITED

Now i have this in my code

<h:form id="formAdminAccesosXPerfil">

    <h:panelGrid title="Accesos" columns="5">

    <c:forEach items="#{accesosXPerfilMB.listadoAcceso}" var="availableItem" varStatus="loop">

             <h:panelGroup>
                <p:selectBooleanCheckbox id="box_#{loop.index}" value="#{accesosXPerfilMB.checkBoxItems[availableItem]}" />
                <h:outputLabel for="box_#{loop.index}" value="#{availableItem.nombre}" />
            </h:panelGroup>
    </c:forEach>    

    </h:panelGrid>

The Managebean which is @ViewScoped

I changed the method suggested because it did not work for me...

from:

public void save() {
List<E> selectedItems = checkboxItems.entrySet().stream()
    .filter(e -> e.getValue() == Boolean.TRUE)
    .map(e -> e.getKey())
    .collect(Collectors.toList());
// ...

}

to this:

public void guardarAccesos(){
    try {
        System.out.println("Size: "+getCheckBoxItems().entrySet().size());

        for(BpAcceso acceso:getCheckBoxItems().keySet()){
            System.out.println("Acceso Seleccionado: "+acceso.getNombre());
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

But i do not get any selected item on the hashMap. Just to make sure i am using jdk1.6

Answer 1

Generate a bunch of selectBooleanCheckbox components in a <c:forEach> loop in a <h:panelGrid columns="X"> and alter the model from List<E> to Map<E, Boolean>.

So, instead of

private List<E> selectedItems;
private List<E> availableItems;

<p:selectManyCheckbox value="#{bean.selectedItems}">
    <f:selectItems value="#{bean.availableItems}" />
</p:selectBooleanCheckbox>

do

private Map<E, Boolean> checkboxItems;
private List<E> availableItems;

@PostConstruct
public void init() {
    checkboxItems = new HashMap<>();
}

<h:panelGrid columns="4">
    <c:forEach items="#{bean.availableItems}" var="availableItem" varStatus="loop">
        <h:panelGroup>
            <p:selectBooleanCheckbox id="box_#{loop.index}" value="#{bean.checkboxItems[availableItem]}" />
            <h:outputLabel for="box_#{loop.index}" value="#{availableItem}" />
        </h:panelGroup>
    </c:forEach>
</h:panelGrid>

public void save() {
    List<E> selectedItems = checkboxItems.entrySet().stream()
        .filter(e -> e.getValue() == Boolean.TRUE)
        .map(e -> e.getKey())
        .collect(Collectors.toList());
    // ...
}

Note that an <ui:repeat> is not applicable for the reasons explained here JSTL in JSF2 Facelets... makes sense?