Bootstrap responsive pagination widget for Yii

ResponsiveLinkPager.php

<?php
namespace app\utils\widgets;

use yii\helpers\Html;
use yii\widgets\LinkPager;

/**
 * ResponsiveLinkPager can reduce or style each buttons for responsive design.
 *
 * Define CSS classes as if maxButtonCount would be so. For example below applies hidden-xs class
 * to page buttons to show only 5 buttons for narrow device.
 *
 * ~~~
 * <?= ResponsiveLinkPager::widget([
 *     'pagination' => $dataProvider->pagination,
 *     'maxButtonCount' => 10,
 *     'pageCssClassButtonCountMap' => [
 *         'hidden-xs' => 5,
 *     ],
 * ]) ?>
 * ~~~
 *
 * ~~~
 * <?= ListView::widget([
 *     'dataProvider' => $dataProvider,
 *     // ...
 *     'pager' => [
 *         'class' => ResponsiveLinkPager::className(),
 *         'maxButtonCount' => 10,
 *         'pageCssClassButtonCountMap' => [
 *             'hidden-xs' => 5,
 *         ]
 *     ]
 * ]) ?>
 * ~~~
 */
class ResponsiveLinkPager extends LinkPager
{
    /**
     * @var array
     */
    public $pageCssClassButtonCountMap = [];

    /**
     * @inheritdoc
     */
    protected function renderPageButtons()
    {
        $pageCount = $this->pagination->getPageCount();
        if ($pageCount < 2 && $this->hideOnSinglePage) {
            return '';
        }

        $buttons = [];
        $currentPage = $this->pagination->getPage();

        // first page
        $firstPageLabel = $this->firstPageLabel === true ? '1' : $this->firstPageLabel;
        if ($firstPageLabel !== false) {
            $buttons[] = $this->renderPageButton($firstPageLabel, 0, $this->firstPageCssClass, $currentPage <= 0, false);
        }

        // prev page
        if ($this->prevPageLabel !== false) {
            if (($page = $currentPage - 1) < 0) {
                $page = 0;
            }
            $buttons[] = $this->renderPageButton($this->prevPageLabel, $page, $this->prevPageCssClass, $currentPage <= 0, false);
        }

        // internal pages
        list($beginPage, $endPage) = $this->getPageRange();

        //////////////////////////////// modification begin
        $class2ranges = [];
        foreach ($this->pageCssClassButtonCountMap as $class => $buttonCount) {
            $class2ranges[$class] = $this->buttonsVisibilityRange($currentPage, $beginPage, $endPage, $buttonCount);
        }
        for ($i = $beginPage; $i <= $endPage; ++$i) {
            $classes = [];
            foreach ($class2ranges as $class => $range) {
                list($leftLimit, $rightLimit) = $range;
                if (!($i >= $leftLimit && $i <= $rightLimit)) {
                    $classes[] = $class;
                }
            }
            $buttons[] = $this->renderPageButton($i + 1, $i, implode(' ', $classes), false, $i == $currentPage);
        }
        //////////////////////////////// end

        // next page
        if ($this->nextPageLabel !== false) {
            if (($page = $currentPage + 1) >= $pageCount - 1) {
                $page = $pageCount - 1;
            }
            $buttons[] = $this->renderPageButton($this->nextPageLabel, $page, $this->nextPageCssClass, $currentPage >= $pageCount - 1, false);
        }

        // last page
        $lastPageLabel = $this->lastPageLabel === true ? $pageCount : $this->lastPageLabel;
        if ($lastPageLabel !== false) {
            $buttons[] = $this->renderPageButton($lastPageLabel, $pageCount - 1, $this->lastPageCssClass, $currentPage >= $pageCount - 1, false);
        }

        return Html::tag('ul', implode("\n", $buttons), $this->options);
    }

    /**
     * @param integer $active
     * @param integer $begin
     * @param integer $end
     * @param integer $buttonCount
     * @return array
     */
    protected function buttonsVisibilityRange($active, $begin, $end, $buttonCount)
    {
        $leftLimit = $active - floor($buttonCount / 2);
        if ($leftLimit < $begin) {
            $leftLimit = $begin;
        }
        $rightLimit = $leftLimit + $buttonCount - 1;
        if ($rightLimit > $end) {
            $leftLimit -= $rightLimit - $end;
            if ($leftLimit < $begin) {
                $leftLimit = $begin;
            }
            $rightLimit = $end;
        }
        return [$leftLimit, $rightLimit];
    }
}