https://svazkvetinaruafloristu.cz/js/jquery.autoresize.js

1/*!
2 * jQuery textarea autoResize plugin v0.0.2 - 2016-08-31
3 * http://github.com/kipruss/jquery-autoresize
4 * Author: Konstantin Baev for Magic Web Solutions ( http://magicwebsolutions.co.uk/ )
5 * Licensed under the MIT license
6 */
7
8;(function() {
9    'use strict';
10
11    var $ = this.$,
12
13        defaults = {
14            resize: $.noop,
15            'minRows': 1,
16            'maxRows': 0
17        };
18
19    $.fn.autoResize = function(options) {
20        var settings = $.extend({}, defaults, options);
21
22        this.filter('textarea').each(function() {
23
24            var $textarea = $(this).css({
25                    'overflow-y': 'hidden',
26                    'height': 'auto',
27                    'resize': 'none'
28                });
29
30            var textarea = $textarea.get(0);
31
32            var setBaseScrollHeight = function () {
33                var savedValue = textarea.value;
34                var savedRows = textarea.rows;
35                textarea.value = '';
36                textarea.rows = 1;
37                textarea.baseScrollHeight = textarea.scrollHeight;
38                textarea.value = savedValue;
39                textarea.rows = savedRows;
40            };
41
42            var init = function () {
43                if (!textarea.scrollHeight) return false;
44                if (textarea.baseScrollHeight) return true;
45                setBaseScrollHeight();
46                return true;
47            };
48
49            var setRows = function () {
50                if (!init()) return false;
51                var lineHeight = parseFloat($textarea.css('line-height'));
52                textarea.rows = settings.minRows;
53                var rows = Math.round((textarea.scrollHeight - textarea.baseScrollHeight) / lineHeight) + 1;
54                if (settings.maxRows > settings.minRows && rows > settings.maxRows) {
55                    textarea.rows = settings.maxRows;
56                    $textarea.css({ 'overflow-y': 'auto' });
57                } else {
58                    textarea.rows = Math.max(rows, settings.minRows);
59                    $textarea.css({ 'overflow-y': 'hidden' });
60                }
61            };
62
63            if (!textarea.rows || textarea.rows < settings.minRows) {
64                textarea.rows = settings.minRows;
65            }
66            $textarea.off('.resize');
67
68            if (supportsInputEvent()) {
69                $textarea.on('input.resize', setRows);
70            } else if (supportsPropertyChangeEvent()) {
71                $textarea.on('propertychange.resize', setRows);
72            } else {
73                $textarea.on('keypress.resize', setRows);
74            }
75            $textarea.one('focus', setRows);
76            setRows();
77        });
78
79        return this;
80    };
81
82    function supportsInputEvent() {
83        if ('oninput' in document.body) {
84            return true;
85        }
86
87        document.body.setAttribute('oninput', 'return');
88
89        var supports = typeof document.body.oninput === 'function';
90        delete document.body.oninput;
91        return supports;
92    }
93
94    function supportsPropertyChangeEvent() {
95        return 'onpropertychange' in document.body;
96    }
97
98}).call(this);