Change height of div smoothly

Question

I have got this:

$('#btn-adm2').on('mouseover', function (event) {
    $('#btn-adm2 .menu-text').css('height', '100%');
});
$('#btn-adm2').on('mouseout', function (event) {
    $('#btn-adm2 .menu-text').css('height', '');
});

.menu-btn {
    width: 100px;
    height: 100px;
    position: relative;
    margin: auto;
    overflow: hidden;
    border-radius: 20px;
    border: 3px solid White;
    background-color: rgb(220, 220, 220);
    box-sizing: border-box;
    box-shadow: 10px 10px 40px rgba(0, 0, 0, 0.2);
    transition: all 100ms linear;
}
.menu-btn:hover {
    background-color: white;
    border: 3px solid #0089c8;
    /* Azul Ascendi */
    transition: border 0.75s ease-in-out;
}
.menu-btn:hover .menu-text {
    background-color: rgba(255, 255, 255, .8);
    color: black;
    transition: all 250ms linear;
}
.menu-item-div-top {
    width: 25%;
    height: 50%;
    
    box-sizing: border-box;
    display: inline-block;
}

.menu-text {
    color: white;
    font-size: 1.8vw;
    line-height: 4vw;
    position: absolute;
    width: 100%;
    text-align: center;
    transition: all 100ms linear;
    bottom: 0;
    border-bottom-left-radius: 20px;
    border-bottom-right-radius: 20px;
    background-color: rgba(0, 0, 0, 0.5);
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

    <div class="menu-item-div-top"> <a href="#" onclick="underConstruction()">
            <div id="btn-adm2" class="menu-btn" style="background-image: url('http://icons.iconarchive.com/icons/mazenl77/I-like-buttons-3a/512/Cute-Ball-Go-icon.png'); background-size: cover;">
                <span class="menu-text">Press</span>
            </div>
        </a>
    </div>

On hover, the height of the text div becomes 100%. I want it to grow with some animation instead of just turning into a full height div. I'm looking for the div to expand its height until the top of the button but I don't know how. Any help?

Answer 1

You are trying to add a transition for height 100%. That is a little tricky for some browsers. Instead, try using the transition on max-height. Transitions on max-height usually is a much better way of using transitions.

You'll have to modify the code as below:

Add height and set a value as max-height to menu-text properties. I have set it to 25px in this example:

.menu-text {
    color: white;
    font-size: 1.8vw;
    line-height: 4vw;
    position: absolute;
    width: 100%;
    text-align: center;
    transition: all 100ms linear;
    bottom: 0;
    border-bottom-left-radius: 20px;
    border-bottom-right-radius: 20px;
    background-color: rgba(0, 0, 0, 0.5);
    height:100%;
    max-height:25px;
}

and change the max-height value on mouseover and mouseout events as below:

$('#btn-adm2').on('mouseover', function (event) {
    $('#btn-adm2 .menu-text').css('max-height', '100%');        
});
$('#btn-adm2').on('mouseout', function (event) {
    $('#btn-adm2 .menu-text').css('max-height', '25px');
});

See this here -> http://jsfiddle.net/09ov6gn4/

Hope this helps!!!

Answer 2

You can use jQuery animate as well:

$('#btn-adm2').on('mouseover', function (event) {
    $("#btn-adm2 .menu-text").animate({height:"100%"}, 10);
});
$('#btn-adm2').on('mouseout', function (event) {
    $("#btn-adm2 .menu-text").animate({height:"25px"}, 10);
});

http://jsfiddle.net/o6hz9tra/