public/lib/jquery.sly.js
function updateNavButtonsState() {
            // Item navigation
            if (itemNav) {
                var isFirst = rel.activeItem === 0,
                    isLast  = rel.activeItem >= items.length - 1,
                    itemsButtonState = isFirst ? 'first' : isLast ? 'last' : 'middle';

                if (last.itemsButtonState !== itemsButtonState) {
                    last.itemsButtonState = itemsButtonState;

                    if ($prevButton.is('button,input')) {
                        $prevButton.prop('disabled', isFirst);
                    }

                    if ($nextButton.is('button,input')) {
                        $nextButton.prop('disabled', isLast);
                    }

                    $prevButton[isFirst ? 'removeClass' : 'addClass'](o.disabledClass);
                    $nextButton[isLast ? 'removeClass' : 'addClass'](o.disabledClass);
                }
            }

            // Page navigation
            if ($pages[0]) {
                var isStart = pos.dest <= pos.start,
                    isEnd = pos.dest >= pos.end,
                    pagesButtonState = isStart ? 'first' : isEnd ? 'last' : 'middle';

                // Update paging buttons only if there has been a change in their state
                if (last.pagesButtonState !== pagesButtonState) {
                    last.pagesButtonState = pagesButtonState;

                    if ($prevPageButton.is('button,input')) {
                        $prevPageButton.prop('disabled', isStart);
                    }

                    if ($nextPageButton.is('button,input')) {
                        $nextPageButton.prop('disabled', isEnd);
                    }

                    $prevPageButton[isStart ? 'removeClass' : 'addClass'](o.disabledClass);
                    $nextPageButton[isEnd ? 'removeClass' : 'addClass'](o.disabledClass);
                }
            }
        }
function updateNavButtonsState() {
            // Item navigation
            if (itemNav) {
                var isFirst = rel.activeItem === 0,
                    isLast  = rel.activeItem >= items.length - 1,
                    itemsButtonState = isFirst ? 'first' : isLast ? 'last' : 'middle';

                if (last.itemsButtonState !== itemsButtonState) {
                    last.itemsButtonState = itemsButtonState;

                    if ($prevButton.is('button,input')) {
                        $prevButton.prop('disabled', isFirst);
                    }

                    if ($nextButton.is('button,input')) {
                        $nextButton.prop('disabled', isLast);
                    }

                    $prevButton[isFirst ? 'removeClass' : 'addClass'](o.disabledClass);
                    $nextButton[isLast ? 'removeClass' : 'addClass'](o.disabledClass);
                }
            }

            // Page navigation
            if ($pages[0]) {
                var isStart = pos.dest <= pos.start,
                    isEnd = pos.dest >= pos.end,
                    pagesButtonState = isStart ? 'first' : isEnd ? 'last' : 'middle';

                // Update paging buttons only if there has been a change in their state
                if (last.pagesButtonState !== pagesButtonState) {
                    last.pagesButtonState = pagesButtonState;

                    if ($prevPageButton.is('button,input')) {
                        $prevPageButton.prop('disabled', isStart);
                    }

                    if ($nextPageButton.is('button,input')) {
                        $nextPageButton.prop('disabled', isEnd);
                    }

                    $prevPageButton[isStart ? 'removeClass' : 'addClass'](o.disabledClass);
                    $nextPageButton[isEnd ? 'removeClass' : 'addClass'](o.disabledClass);
                }
            }
        }
function updateNavButtonsState ( ) { // Item navigation
 if ( itemNav ) { var isFirst = rel . activeItem === 0 , isLast = rel . activeItem >= items . length - 1 , itemsButtonState = isFirst ? 'first' : isLast ? 'last' : 'middle' ; if ( last . itemsButtonState !== itemsButtonState ) { last . itemsButtonState = itemsButtonState ; if ( $prevButton . is ( 'button,input' ) ) { $prevButton . prop ( 'disabled' , isFirst ) ; } if ( $nextButton . is ( 'button,input' ) ) { $nextButton . prop ( 'disabled' , isLast ) ; } $prevButton [ isFirst ? 'removeClass' : 'addClass' ] ( o . disabledClass ) ; $nextButton [ isLast ? 'removeClass' : 'addClass' ] ( o . disabledClass ) ; } } // Page navigation
 if ( $pages [ 0 ] ) { var isStart = pos . dest <= pos . start , isEnd = pos . dest >= pos . end , pagesButtonState = isStart ? 'first' : isEnd ? 'last' : 'middle' ; // Update paging buttons only if there has been a change in their state
 if ( last . pagesButtonState !== pagesButtonState ) { last . pagesButtonState = pagesButtonState ; if ( $prevPageButton . is ( 'button,input' ) ) { $prevPageButton . prop ( 'disabled' , isStart ) ; } if ( $nextPageButton . is ( 'button,input' ) ) { $nextPageButton . prop ( 'disabled' , isEnd ) ; } $prevPageButton [ isStart ? 'removeClass' : 'addClass' ] ( o . disabledClass ) ; $nextPageButton [ isEnd ? 'removeClass' : 'addClass' ] ( o . disabledClass ) ; } } }
Disable navigation buttons when needed.

Adds disabledClass, and when the button is <button> or <input>, activates :disabled state.

@return {Void}
Disable navigation buttons when needed .