Hack23/cia

/*
 * Copyright 2010-2021 James Pether Sörling
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *    $Id$
 *  $HeadURL$
*/
package com.hack23.cia.web.impl.ui.application.views.common.paging;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.hack23.cia.web.impl.ui.application.views.common.pagelinks.api.PageLinkFactory;
import com.hack23.cia.web.impl.ui.application.views.common.sizing.ContentRatio;
import com.vaadin.ui.AbstractOrderedLayout;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.Label;
import com.vaadin.ui.Link;

/**
 * The Class PagingUtil.
 */
@Component
public final class PagingUtilImpl implements PagingUtil {

    /** The first page. */
    private static final String FIRST_PAGE = "first page";

    /** The last page. */
    private static final String LAST_PAGE = "last page";

    /** The limit for displaying start end links. */
    private static final int LIMIT_FOR_DISPLAYING_START_END_LINKS = 5;

    /** The next page. */
    private static final String NEXT_PAGE = "next page";

    /** The page header. */
    private static final String PAGE_HEADER = "Page: ";

    /** The page one. */
    private static final int PAGE_ONE = 1;

    /** The page separator. */
    private static final char PAGE_SEPARATOR = '/';

    /** The pages total results. */
    private static final String PAGES_TOTAL_RESULTS = " pages. Total results:";

    /** The previous page. */
    private static final String PREVIOUS_PAGE = "previous page";

    /** The results per page. */
    private static final String RESULTS_PER_PAGE = " results per page:";

    /** The show. */
    private static final String SHOW = " :: Show ";

    /** The page link factory. */
    @Autowired
    private PageLinkFactory pageLinkFactory;

    /**
     * Adds the paging link.
     *
     * @param label          the label
     * @param name           the name
     * @param pageId         the page id
     * @param maxPages       the max pages
     * @param pagingControls the paging controls
     */
    private void addPagingLink(final String label, final String name, final String pageId, final long maxPages, final HorizontalLayout pagingControls) {
        final Link previousPageLink = pageLinkFactory.createAdminPagingLink(label,name, pageId, String.valueOf(maxPages));
        pagingControls.addComponent(previousPageLink);
        pagingControls.setExpandRatio(previousPageLink, ContentRatio.SMALL);
    }

    /**
     * Creates the paging controls.
     *
     * @param content       the content
     * @param name          the name
     * @param pageId        the page id
     * @param size          the size
     * @param pageNr        the page nr
     * @param resultPerPage the result per page
     */
    @Override
    public void createPagingControls(final AbstractOrderedLayout content, final String name, final String pageId, final Long size, final int pageNr,
            final int resultPerPage) {
                final HorizontalLayout pagingControls = new HorizontalLayout();
                pagingControls.setSpacing(true);
                pagingControls.setMargin(true);

                final long maxPages = (size +resultPerPage-1) / resultPerPage;

                final StringBuilder stringBuilder = new StringBuilder();
                stringBuilder.append(PAGE_HEADER)
                .append(pageNr)
                .append(PAGE_SEPARATOR)
                .append(maxPages)
                .append(PAGES_TOTAL_RESULTS)
                .append(size)
                .append(RESULTS_PER_PAGE)
                .append(resultPerPage)
                .append(SHOW);
                final Label pageInfo = new Label(stringBuilder.toString());
                pagingControls.addComponent(pageInfo);
                pagingControls.setExpandRatio(pageInfo, ContentRatio.SMALL);


                if (pageNr > PAGE_ONE) {
                    addPagingLink(PREVIOUS_PAGE,name, pageId, pageNr -1L,pagingControls);
                }

                if (maxPages > PAGE_ONE && pageNr < maxPages) {
                    addPagingLink(NEXT_PAGE,name, pageId, pageNr +1L,pagingControls);
                }

                if (maxPages > LIMIT_FOR_DISPLAYING_START_END_LINKS && pageNr > PAGE_ONE) {
                    addPagingLink(FIRST_PAGE,name, pageId, 1,pagingControls);
                }

                if (maxPages > LIMIT_FOR_DISPLAYING_START_END_LINKS && pageNr < maxPages) {
                    addPagingLink(LAST_PAGE,name, pageId, maxPages,pagingControls);
                }

                content.addComponent(pagingControls);
                content.setExpandRatio(pagingControls, ContentRatio.SMALL2);

            }

}