I'm trying to replicate a input horizontal scroll on a div element, so whenever the user move along the input the div element scrolls exactly the same as the input.
My problem is with Chrome as it seems the input has a different scroll behavior, causing the scrollLeft value to be different in both elements. In Firefox it works as expected.
Is there any way to achieve this in Chrome without using jQuery or other libraries? or am I asking the impossible?
var theTextDiv = document.getElementById("the-text");
var theText = document.getElementById("the-text-input");
function keepScroll(txt) {
theTextDiv.scrollLeft = theText.scrollLeft;
}
theText.addEventListener("blur", function() { keepScroll("blur"); });
theText.addEventListener("change", function() { keepScroll("change"); });
theText.addEventListener("focus", function() { keepScroll("focus"); });
theText.addEventListener("input", function() { keepScroll("input"); });
theText.addEventListener("keydown", function() { keepScroll("keydown"); });
theText.addEventListener("keyup", function() { keepScroll("keyup"); });
theText.addEventListener("scroll", function() { keepScroll("scroll"); });
theText.addEventListener("select", function() { keepScroll("select"); });
#the-text {
border: 1px solid red;
max-width: 98px;
font-size: 14px;
overflow-x: scroll;
word-wrap: break-word;
white-space: nowrap;
font-family: "Times New Roman", Times, serif;
padding: 1px;
margin-right: 10px;
}
#the-text-input {
border: 1px solid red;
width: 100px;
font-size: 14px;
font-family: "Times New Roman", Times, serif;
}
<div id="the-text">
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
</div>
<input type="text" id="the-text-input" value="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua." />
EDIT:
I tried the above code on Chrome 77 on a Mac and it works as expected, there's no gap between both elements, and I'm starting to think this is a Windows problem rather than a Chrome problem
EDIT(2):
After restarting my PC all work as expected (seriously) maybe some chrome cache was causing to have a weird behavior
This probably has to do with paddings and borders on the input and/or the div, and as it looks like it's working fine in Chrome 77, you either forgot to add some code in the example you posted or the default styles for those elements are also playing a role here.
In any case, my suggestion would be to remove margins, paddings and borders from both elements and adding a wrapping div with those instead (red example).
You can also use box-sizing: border-box, keep those styles and avoid the wrapper, but padding behaves differently in an input, as content in the padding area is not visible (blue example).
Lastly, your code to update the scroll was not working properly on blur, as when the event fires the scroll on the input hasn't been reset to 0 yet. Wrapping it with setTimeout or window.requestAnimationFrame solves the issue. Additionally, the latter will also make the update much smoother and in-sync.
const text = document.getElementById('text');
const input = document.getElementById('input');
function updateScroll() {
// Scroll not updated on blur without requestAnimationFrame
// or setTimeout:
requestAnimationFrame(() => text.scrollLeft = input.scrollLeft);
}
input.addEventListener('blur', updateScroll);
input.addEventListener('change', updateScroll);
input.addEventListener('focus', updateScroll);
input.addEventListener('input', updateScroll);
input.addEventListener('keydown', updateScroll);
input.addEventListener('keyup', updateScroll);
input.addEventListener('scroll', updateScroll);
input.addEventListener('select', updateScroll);
const textAlternative = document.getElementById('text-alternative');
const inputAlternative = document.getElementById('input-alternative');
function updateScrollAlternative() {
// Scroll not updated on blur without requestAnimationFrame
// or setTimeout:
requestAnimationFrame(() => textAlternative.scrollLeft = inputAlternative.scrollLeft);
}
inputAlternative.addEventListener('blur', updateScrollAlternative);
inputAlternative.addEventListener('change', updateScrollAlternative);
inputAlternative.addEventListener('focus', updateScrollAlternative);
inputAlternative.addEventListener('input', updateScrollAlternative);
inputAlternative.addEventListener('keydown', updateScrollAlternative);
inputAlternative.addEventListener('keyup', updateScrollAlternative);
inputAlternative.addEventListener('scroll', updateScrollAlternative);
inputAlternative.addEventListener('select', updateScrollAlternative);
body {
margin: 0;
}
.box {
position: relative;
display: block;
width: 50%;
box-sizing: border-box;
/* Moved styles here: */
border: 3px solid red;
padding: 8px;
margin: 8px auto 0;
}
#text,
#input,
#text-alternative,
#input-alternative {
display: block;
width: 100%;
font-size: 14px;
font-family: monospace;
outline: none;
}
#text,
#input {
/* Removed margin, padding and borders: */
border: 0;
padding: 0;
margin: 0;
}
#text-alternative,
#input-alternative {
width: 50%;
box-sizing: border-box;
/* Keep styles here thanks to box-sizing, but behaves differently: */
border: 3px solid blue;
padding: 8px;
margin: 8px auto 0;
}
#text,
#text-alternative {
word-wrap: break-word;
white-space: nowrap;
/* No need to keep it visible unless you want to scroll manually too: */
overflow-x: hidden;
}
<div class="box">
<div id="text">
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
</div>
</div>
<label class="box">
<input id="input" value="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua." />
</label>
<div id="text-alternative">
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
</div>
<input id="input-alternative" value="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua." />
Related
I coded this:
$("#scroll-to-left-button").on("mousedown", function() {
var x = $("#scroll-area").scrollLeft();
$("#scroll-area").scrollLeft(x - 10);
});
$("#scroll-to-right-button").on("mousedown", function() {
var x = $("#scroll-area").scrollLeft();
$("#scroll-area").scrollLeft(x + 10);
});
#container {
width: 50%;
height: 100px;
background-color: grey;
position: relative;
}
#scroll-area {
white-space: nowrap;
overflow-x: auto;
height: 100%;
}
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<div id="container">
<div id="scroll-area">
<div id="text">Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.</div>
</div>
</div>
<button id="scroll-to-left-button">Scroll to left</button>
<button id="scroll-to-right-button">Scroll to right</button>
You need to click the buttons pretty often to navigate through this container. Is there a way to let it based on the duration of the mouse press? Like if you keep the mouse pressed, it continues constantly scrolling? And if you stop, it stops.
Would be happy if someone could help me.
Here's a working solution. Also your code was a bit wet, so I refactored it a bit. You only need one mousedown event listener.
let interval;
$('.scroll-btn').on('mousedown', ({ target }) => {
const type = $(target).attr('id');
interval = setInterval(() => {
var x = $('#scroll-area').scrollLeft();
$('#scroll-area').scrollLeft(type === 'left' ? x - 10 : x + 10);
}, 50);
});
$('.scroll-btn').on('mouseout mouseup', () => clearInterval(interval));
#container {
width: 50%;
height: 100px;
background-color: grey;
position: relative;
}
#scroll-area {
white-space: nowrap;
overflow-x: auto;
height: 100%;
}
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<div id="container">
<div id="scroll-area">
<div id="text">
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat,
sed diam voluptua.
</div>
</div>
</div>
<button id="left" class="scroll-btn">Scroll Left</button>
<button id="right" class="scroll-btn">Scroll Right</button>
Well, the mousedown and mouseup make a good pair, although you have used only mousedown :)
Here's a sample how it could be done.
Note that there're couple other things that could be done to this code for it to look nicer:
.on(... is not probably needed, you could just write it as .mousedown(...
the code for the right and left buttons look really similar, you could unite these blocks in one and distinguish by an additional attrubute (let's say like move="10" for the right button and move="-10" for the left one, and then just getting this value in order to add it to scrollLeft)
var tmr;
$(".scroll-button").mousedown(function() {
//let's setup the timer here...
move = +$(this).attr("move");
tmr = setInterval(function(){
$("#scroll-area")[0].scrollLeft+=move;
}, 250)
});
$(".scroll-button").mouseup(function() {
// and destroy the timer here
clearInterval(tmr);
});
#container {
width: 50%;
height: 300px;
background-color: grey;
position: relative;
}
#scroll-area {
white-space: nowrap;
overflow-x: auto;
height: 100%;
}
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<div id="container">
<div id="scroll-area">
<div id="text">Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.</div>
</div>
</div>
<button class="scroll-button" move="-10">Scroll to left</button>
<button class="scroll-button" move="10">Scroll to right</button>
I have an unordered list of over 10 list items which I need to add mouse events to. The onMouseover and onMouseout works just with the first list item but does not work with all the other list item. I need the mouse events to work on all the lists
const showSlideElement = (myID) => {
document.querySelector(myID).style.display = 'block';
document.querySelector('.services-box').style.height = '110px';
}
const hideElement = (myID) => {
document.querySelector(myID).style.display = 'none';
document.querySelector('.services-box').style.height = '26px';
}
.slideList {
width: 100%;
}
.slideList li {
position: relative;
}
.slideList .service-highlight {
background-color: #0088ff;
position: absolute;
color: white;
bottom: 0;
left: 0;
right: 0;
}
.slideList .service-highlight p {
display: inline-block;
color: white;
font-size: 18px;
font-weight: bold;
}
.slideList .service-highlight .services-box {
text-align: center;
background-color: #003768;
width: 270px;
font-weight: bold;
float: left;
}
.slideList .service-highlight .services-detail {
width: calc(100% - 270px);
float: left;
padding-left: 5px;
}
.slideList .hide-description {
display: none;
font-weight: normal;
}
.slideList .hide-description p {
font-weight: normal;
padding-top: 10px 5px 10px;
}
<ul class="slideList">
<li data-transition="fade">
<img src="https://cdn.pixabay.com/photo/2015/12/01/20/28/road-1072823_960_720.jpg" alt="" width="1920" height="630">
<div class="service-highlight" onMouseover='showSlideElement(`.hide-description`)' onMouseout='hideElement(`.hide-description`)'>
<p class="services-box">SOME SERVICES:</p>
<div class="services-detail">
<p>The service headline</p>
<div class="hide-description">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam</p>
</div>
</div>
</div>
</li>
<li data-transition="fade">
<img src="https://cdn.pixabay.com/photo/2018/01/12/10/19/fantasy-3077928_960_720.jpg" alt="" width="1920" height="630">
<div class="service-highlight" onMouseover='showSlideElement(`.hide-description`)' onMouseout='hideElement(`.hide-description`)'>
<p class="services-box">SOME SERVICES:</p>
<div class="services-detail">
<p>The service headline</p>
<div class="hide-description">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam</p>
</div>
</div>
</div>
</li>
</ul>
This can all be achieved using simple CSS:
.hide-description {
display: none;
}
.services-box {
height: 26px;
background: #0bf;
transition: 0.4s;
}
.service-highlight:hover .hide-description {
display: block;
}
.service-highlight:hover .services-box {
height: 110px;
}
<div class="service-highlight">
<p class="services-box">SOME SERVICES:</p>
<div class="services-detail">
<p>The service headline</p>
<div class="hide-description">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam</p>
</div>
</div>
</div>
I have 3 identical divs and I want to add a class to one of those divs every 5 seconds one a rotating carousel type thing.
The following JSFiddle is what I have atm and I want the :hover styles to to be added to one of those divs every 5 seconds in a rotating sequence but still work as an on hover; JSFiddle
.action {
padding: 10px 50px 10px 10px;
background-color: #eaeaea;
color: #525454;
}
.action:hover {
background-color: #b5b5b5;
color: #000;
}
.action h3 {
margin: 0 0 10px 0;
}
.action .corner {
position: absolute;
width: 0;
height: 0;
border-bottom: 50px solid #db7575;
border-left: 50px solid transparent;
bottom: 0;
right: 0;
}
.action:hover .corner {
border-bottom: 50px solid #CC0000;
}
.action i {
position: absolute;
margin-left: -20px;
margin-top: 27px;
color: #fff;
}
<div class="row">
<a href="#">
<div class="col-md-4 action">
<h3> Title 1 </h3>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam.</p> <span class="corner "><i class="fa fa-arrow-right"></i></span>
</div>
</a>
<a href="#">
<div class="col-md-4 action">
<h3> Title 2 </h3>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam.</p> <span class="corner "><i class="fa fa-arrow-right"></i></span>
</div>
</a>
<a href="#">
<div class="col-md-4 action">
<h3> Title 3 </h3>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam.</p> <span class="corner "><i class="fa fa-arrow-right"></i></span>
</div>
</a>
</div>
Something like this ?
http://jsfiddle.net/15od56d3/
CSS
.action:hover,.my_turn { background-color: #b5b5b5; color: #000;}
Javascript
var myTurn = 0;
setInterval(function(){
var i = 0;
$(".action").each(function(){
if(i==myTurn)
$(this).addClass("my_turn");
else
$(this).removeClass("my_turn");
i++;
});
myTurn = (myTurn + 1)%3 ;
},5000);
What I don't get in the accepted answer is that the carousel doesn't pause when the mouse hovers over an item. This is very confusing, especially since the same style is applied. I would create a jQuery object of the rows and use the available jQuery functions to walk over/select them and apply the a class for the hover instead of using the css property.
See the JSFiddle for a demo
var $rows = $('.action');
var $start= $rows.first(); // select one to start with (can be any of the elements in the set)
var $current = $start;
var interval;
var hover = function() {
$current.removeClass('hover');
$current = $rows.eq($rows.index($current)+1);
if (!$current.length) {
$current = $rows.eq($rows.index($start));
}
$current.addClass('hover');
};
The carousel should keep the expected direction and move on from where the hover-style was last applied; from the hovered element (as this is the most natural behavior imho):
$('.action').mouseover(function() {
window.clearInterval(interval);
$current.removeClass('hover');
$current = $(this).addClass('hover');
}).mouseout(function() {
interval = window.setInterval(hover, 2000);
});
$start.addClass('hover').mouseout(); // apply the class immediately to the first row
This is the HTML I got:
<div class="preview-content">
<h1 class="preview-content-header">Vorschau - Notiz1.txt <img src="icons/cross.png" /></h2>
<div>
<h2>Notiz1.txt</h2>
<p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
</div>
</div>
<img id="preview-toggle" src="icons/preview.png">
<div class="main-content">
<h2 class="main-content-header">Datenbank</h2>
<div id="table">
</div>
</div>
This is the corresponding CSS:
/* General Style */
html, body {
margin: 0px;
padding: 0px;
background: $background-color;
font-family: $font;
overflow-x: hidden;
}
/* Main Content */
div.main-content {
padding: 50px 0px 20px 70px;
width: 45%;
overflow: auto;
h2.main-content-header {
margin: 0;
}
}
#preview-toggle {
display: none ;
position: fixed;
z-index: 3;
top: 50px;
right: 0;
width: 40px;
height: 40px;
padding: 5px;
background-color: $nav-color;
color: $font-color-secondary;
cursor: pointer;
transition: .3s background-color;
-webkit-transition: .3s background-color;
}
#preview-toggle:hover {
background-color: $main-color;
}
/* Preview */
div.preview-content {
position: fixed;
z-index: 3;
right: 0px;
margin: 0;
width: 50%;
height: 100%;
font-size: 70%;
img {
float: right;
height: 25px;
padding: 0px 15px 0px 0px;
cursor: pointer;
}
h1 {
position: relative;
z-index: 3;
width: 100%;
margin: 0;
padding: 5px 5px 5px 10px;
background-color: $preview-header-color;
color: $font-color-secondary;
white-space: nowrap;
}
div {
position: fixed;
z-index: 3;
height: 100%;
margin: 0;
padding: 10px;
background-color: $data-background-color;
overflow-y: auto;
overflow-x: hidden;
white-space: pre-line;
word-wrap: break-word;
}
}
/* Database table */
#table {
z-index: 1;
}
Here is the animation to toggle the preview container on/off:
$(document).ready(function() {
$(' .preview-content-header img').click(function() {
$('.main-content').animate({
width: "100%"
});
$('.preview-content').animate({
width: "0%"
}, 300, function() {
$('#preview-toggle').toggle();
});
$('.preview-content img').toggle();
});
$('#preview-toggle').click(function() {
$('.main-content').animate({
width: "45%"
});
$('#preview-toggle').toggle();
$('.preview-content').animate({
width: "50%"
}, 300, function() {
$('.preview-content img').toggle();
});
});
});
Here is the code for the Handsontable:
$(document).ready(function() {
var data = [
["Dateiname", "Benutzer", "Erstelldatum", "Änderungsdatum", "Erste Zeile", "Kategorie", "Projekt"],
["Rechnung1.doc", "SB", "01.01.2010", "-", "Internetrechnung", "Rechnungen", "Haushalt"],
["Rechnung2.doc", "SB", "01.01.2012", "-", "Stromrechnung", "Rechnungen", "Haushalt"]
];
var container = $('#table');
container.handsontable({
data: data,
minSpareRows: 1,
rowHeaders: true,
colHeaders: true,
contextMenu: true
});
});
The scenario is as follows:
I've got a .main-content which takes up the whole window containing a Handsontable and a .preview-content which expands it width and shows content as soon as you click on the toggle button within the .main-content. The .preview-content is fixed and doesn't scroll with the .main-content.
The problem is that when the screen displaying the website is not big enough the .preview-content will cover parts of the Handsontable within the .main-content.
To prevent this from happening I wanted to change the width and height of the container containing the Handsontable dynamically so that I get scrollbars in case the table gets covered in parts.
I've tried many things so far but nothing seems to work. And it seems like Handsontable only likes absolute pixel dimensions for its width and height, otherwise overflow: hidden doesn't seem to work.
I've tried to change the width of the .main-content from 100% to 45% and added overflow: auto to the .main-content as you can see in the code, but that doesn't work as it behaves very strange.
Maybe someone has any idea how I can change the width of a Handsontable dynamically?
Your help is very appreciated. And if you need any more info to help me just say it I will see if I can provide the right info.
To dynamically change the width of a Handsontable instance you can do:
hotInstance.updateSettings({
width: newWidth
});
Give that a try as this should take care of the CSS pitfalls of manually setting the .main-content width yourself.
Using the HandsonTable.updateSettings() and jQuery to dynamically resize the table whenever the window is resized:
$(document).ready(function(){
$(window).resize(function(){
hotInstance.updateSettings({
width: $('hotWrapperDiv').width()
});
});
});
you can use resize event of Handsontable, and in calculateSize function write code to calculate height and width
Handsontable.Dom.addEvent(window, 'resize', calculateSize);
I found this code: link
$(".show-more a").on("click", function() {
var $this = $(this);
var $content = $this.parent().prev("div.content");
var linkText = $this.text().toUpperCase();
if(linkText === "SHOW MORE"){
linkText = "Show less";
$content.switchClass("hideContent", "showContent", 400);
} else {
linkText = "Show more";
$content.switchClass("showContent", "hideContent", 400);
};
$this.text(linkText);
});
CSS:
div.text-container {
margin: 0 auto;
width: 75%;
}
.hideContent {
overflow: hidden;
line-height: 1em;
height: 2em;
}
.showContent {
line-height: 1em;
height: auto;
}
.showContent{
height: auto;
}
h1 {
font-size: 24px;
}
p {
padding: 10px 0;
}
.show-more {
padding: 10px 0;
text-align: center;
}
It was exactly what I was looking for, but as you can see here, if you modify it (link), the "Show more" link is there if you have only one or two lines, and it is not needed in that case.
Thank you for your answers!
As your sample code was not fully working I decided to enhance one of my own samples I created in a post a while ago.
DEMO - Show more/less and hide the link when not needed
The demo shows the first text to have no link and the second to have a link. If you add a few more characters to the first text you see the link appear when you run the fiddle again.
The idea is to double check the client vs the actual height and determine then if you want to show the link. Similar to the below.
$(".show-more a").each(function() {
var $link = $(this);
var $content = $link.parent().prev("div.text-content");
console.log($link);
var visibleHeight = $content[0].clientHeight;
var actualHide = $content[0].scrollHeight - 1; // -1 is needed in this example or you get a 1-line offset.
console.log(actualHide);
console.log(visibleHeight);
if (actualHide > visibleHeight) {
$link.show();
} else {
$link.hide();
}
});
The demo is using the following HTML:
<div class="text-container">
<h1>Lorem ipsum dolor</h1>
<div class="text-content short-text">
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut
labore Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt
</div>
<div class="show-more">
Show more
</div>
</div>
<div class="text-container">
<h1>Lorem ipsum dolor</h1>
<div class="text-content short-text">
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.
At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.
</div>
<div class="show-more">
Show more
</div>
</div>
and the following basic CSS:
div.text-container {
margin: 0 auto;
width: 75%;
}
.text-content{
line-height: 1em;
}
.short-text {
overflow: hidden;
height: 2em;
}
.full-text{
height: auto;
}
h1 {
font-size: 24px;
}
.show-more {
padding: 10px 0;
text-align: center;
}
See the working fiddle here - http://jsfiddle.net/tariqulazam/hpeyH/
First you have to measure if the content has overflowed or not. I have used the solution from detect elements overflow using jquery.
Finally use this plugin to decide whether to show or hide the 'show more' link.
$("div.content").HasScrollBar() ==true ? $(".show-more").show():$(".show-more").hide();
I don't know whats your real question is, but I suppose you want to deactive the show more link, if the text is only 1 or 2 lines and active it if the text has more than 2 lines.
For this purpose you have to check if the div with the text is bigger than you threshold (2 lines). In my solution I use the height() function which give you the height in pixel. In the original example the link text is not visible if the height is more than 2em.
You better should use also pixel for that or use a tool to convert the units.
Here are my addition lines for a solution with a threshold of 1 line:
var text = $('.text-container');
if (text.height() <= 20) {
$('.show-more').hide();
}
http://jsfiddle.net/JRDzf/
if( $('.text-container').html().indexOf("<br") >= 0 ) {
$(".show-more").hide()
}