StatelessPagingNavigationLink.java

package org.brixcms.plugin.content.blog.tile.navigation;

import org.apache.wicket.markup.html.navigation.paging.IPageable;
import org.brixcms.web.nodepage.BrixPageParameters;
import org.brixcms.web.nodepage.PageParametersLink;
import org.brixcms.web.util.DisabledClassAppender;

public class StatelessPagingNavigationLink<T> extends PageParametersLink {
    private static final long serialVersionUID = 1L;

    /** The pageable list view. */
    protected final IPageable pageable;

    /** The page of the PageableListView this link is for. */
    private final int pageNumber;

    /**
     * Constructor.
     * 
     * @param id
     *            See Component
     * @param pageable
     *            The pageable component for this page link
     * @param pageNumber
     *            The page number in the PageableListView that this link links
     *            to. Negative pageNumbers are relative to the end of the list.
     */
    public StatelessPagingNavigationLink(final String id, final IPageable pageable, final int pageNumber) {
        super(id);
        this.pageNumber = pageNumber;
        this.pageable = pageable;
        add(new DisabledClassAppender());
    }

    @Override
    protected void contributeToPageParameters(BrixPageParameters parameters) {
        super.contributeToPageParameters(parameters);
        parameters.set(StatelessPagination.PAGE_PARAM_NAME, getPageNumber());
    }

    @Override
    public boolean isEnabled() {
        return !linksTo();
    }

    /**
     * Get pageNumber.
     * 
     * @return pageNumber.
     */
    public final int getPageNumber() {
        return cullPageNumber(pageNumber);
    }

    /**
     * Allows the link to cull the page number to the valid range before it is
     * retrieved from the link
     * 
     * @param pageNumber
     * @return culled page number
     */
    protected int cullPageNumber(int pageNumber) {
        int idx = pageNumber;
        if (idx < 0) {
            idx = (int) pageable.getPageCount() + idx;
        }

        if (idx > (pageable.getPageCount() - 1)) {
            idx = (int) pageable.getPageCount() - 1;
        }

        if (idx < 0) {
            idx = 0;
        }

        return idx;
    }

    /**
     * @return True if this page is the first page of the containing
     *         PageableListView
     */
    public final boolean isFirst() {
        return getPageNumber() == 0;
    }

    /**
     * @return True if this page is the last page of the containing
     *         PageableListView
     */
    public final boolean isLast() {
        return getPageNumber() == (pageable.getPageCount() - 1);
    }

    /**
     * Returns true if this PageableListView navigation link links to the given
     * page.
     * 
     * @param page
     *            The page
     * @return True if this link links to the given page
     * @see org.apache.wicket.markup.html.link.PageLink#linksTo(org.apache.wicket.Page)
     */
    public final boolean linksTo() {
        return getPageNumber() == pageable.getCurrentPage();
    }

}