Reputation: 995
With all the recent advances in JavaScript/HTML5 it would be nice to think there would be a more modern way of implementing an image map. I know you can set a map property for the tag but I don't think this supports nicely formatted tooltips on rollover (near the region). My requirement are really just tooltips, onClick/doubleClick actions on a region within an image.
Last questions on here about similar things I found were from 5 years ago.
Ideally I'd like to use pure js/html/css and not use JQuery plugins etc although I see there are a few available.
Upvotes: 9
Views: 2819
Reputation: 23600
After taking Paulie_D's comment about SVG into account, I wrote an alternative using SVG to the classic image map. Both work fine, but the SVG version clearly wins when it comes to responsiveness. Both versions have a connection between the anchors and the respective tooltip using the href
-attribute. Both solutions work with vanilla JavaScript, without an extra library.
Advantages
HTML
<svg id="map" version="1.1" viewBox="0 0 300 300">
<image width="300" height="300" xlink:href="http://placehold.it/300"/>
<a xlink:href="#t_1">
<rect x="50" y="50" width="50" height="50" />
</a>
<a xlink:href="#t_2">
<rect x="150" y="150" width="50" height="50" />
</a>
</svg>
<div class="t" id="t_1">Tooltip 1</div>
<div class="t" id="t_2">Tooltip 2</div>
CSS
html, body {
width: 100%;
margin: 0;
padding: 0;
}
svg {
display: block;
width: 80%;
max-width: 300px;
margin: 0 auto;
}
svg rect {
fill: white;
opacity: 0.1;
transition: all 0.2s linear;
}
svg rect:hover {
opacity: 0.8;
}
.t {
opacity: 0;
position: absolute;
left: 0;
top: 0;
transition: opacity 0.4s linear;
}
.t.active {
opacity: 1;
}
JavaScript*
var map = document.getElementById('map');
var areas = map.getElementsByTagName('a');
var offset = { left: 30, top: 70 };
for (var i = 0; i < areas.length; i++) {
areas[i].onmouseover = function() {
// get child element
var c = this.firstElementChild;
// get tooltip
var t = document.getElementById(this.getAttribute('xlink:href').substr(1));
// set styles
t.style.left = (map.offsetLeft + parseInt(c.getAttribute('x')) + offset.left) + 'px';
t.style.top = (map.offsetTop + parseInt(c.getAttribute('y')) + offset.top) + 'px';
// show it
t.classList.toggle('active');
}
areas[i].onmouseout = function() {
// get tooltip
var t = document.getElementById(this.getAttribute('xlink:href').substr(1));
// hide it
t.classList.toggle('active');
}
}
Notes
Demo
HTML
<img src="http://placehold.it/300" alt="" usemap="#map">
<map id="map" name="map">
<area shape="rect" coords="0,0,50,50" href="#t_1" alt="Tip 1" data-left="80px" data-top="80px" />
<area shape="rect" coords="100,100,150,150" href="#t_2" alt="Tip 2" data-left="180px" data-top="180px" />
</map>
<div class="t" id="t_1">Tooltip 1</div>
<div class="t" id="t_2">Tooltip 2</div>
CSS
.t {
opacity: 0;
position: absolute;
left: 0;
top: 0;
transition: opacity 0.4s linear;
}
.t.active {
opacity: 1;
}
JavaScript*
var areas = document.getElementById('map').children;
for (var i = 0; i < areas.length; i++) {
areas[i].onmouseover = function() {
var t = document.getElementById(this.hash.substr(1));
t.style.left = this.dataset.left;
t.style.top = this.dataset.top;
t.classList.toggle('active');
}
areas[i].onmouseout = function() {
var t = document.getElementById(this.hash.substr(1));
t.classList.toggle('active');
}
}
Notes
data-*
-attributes, decouples the JavaScript (unfortunately you can't use offsetLeft/Top
and determine the position based on the area
-element) - you could however calculate it by using the coords
-attributeDemo
* In both examples the JavaScript could be improved, e.g. store tooltip elements in a variable instead of re-query them all the time.
Upvotes: 5