https://www.koszalin.pl/sites/all/modules/vtextresize/js/vtextresize.js?t5arh8

1(function($) {    
2    /* DOCUMENT READY */
3    $(document).ready(function() {
4        var currentFontSize;
5        var step = Drupal.settings.vtextresize.step;
6        var maxFontSize = Drupal.settings.vtextresize.max_font_size;
7        var minFontSize = Drupal.settings.vtextresize.min_font_size;        
8        
9        // Hide/show increase/decrease font size links
10        function vtextresize_toggle_link_visibility() {            
11            currentFontSize = parseInt($('body').css('font-size'));
12  
13            var $elLinkDecreaseFontSize = $('a#vtextresize_decrease');
14            var $elLinkIncreaseFontSize = $('a#vtextresize_increase');
15            
16            if (currentFontSize - step < minFontSize) {
17                $elLinkDecreaseFontSize.hide();
18            }
19            else {
20                $elLinkDecreaseFontSize.show();
21            }
22            
23            if (currentFontSize + step > maxFontSize) {
24                $elLinkIncreaseFontSize.hide();
25            }
26            else {
27                $elLinkIncreaseFontSize.show();
28            }            
29        }
30        
31        vtextresize_toggle_link_visibility();
32        
33        // Set font size from cookie
34        if ($.cookie('vtextresize')) {
35            $('body').css('font-size', $.cookie('vtextresize') + 'px');
36        }
37        
38        $('div#block-vtextresize-vtextresize a.vtextresize').click(function(e){            
39            e.preventDefault();
40            
41            var linkID = $(this).attr('id');
42            var currentFontSize = parseInt($('body').css('font-size'));
43            var newFontSize = currentFontSize;
44            
45            switch(linkID) {                
46                case 'vtextresize_decrease':
47                    // Decrease font size
48                    if(currentFontSize - step >= minFontSize) {
49                        newFontSize = currentFontSize - step;
50                    }
51                    break;
52                    
53                case 'vtextresize_increase':
54                    // Increase font size
55                    if(currentFontSize + step <= maxFontSize) {
56                        newFontSize = currentFontSize + step;                        
57                    }
58                    break;
59                    
60                case 'vtextresize_reset':
61                    // Reset font size
62                    // Delete cookie
63                    $.cookie('vtextresize', null, { path: '/', expires: -1 });
64                    // Delete inline style
65                    $('body').css('font-size', '');                    
66
67                    break;
68                
69            }
70            
71            if (newFontSize != currentFontSize) {                
72                // Change body font size
73                $('body').css('font-size', newFontSize + 'px');            
74                
75                // Store cookie
76                $.cookie('vtextresize', newFontSize, { path: '/' });
77            }
78            
79           vtextresize_toggle_link_visibility();
80        });        
81    });
82    
83})(jQuery);