I'm working on a image gallery based on OpenSeaDragon, and I'd like to be able to use overlays in collection mode. Based on the various examples on the OSD website (http://openseadragon.github.io/) I managed to hack together a minimal working example, but there are several issues I've not been able to fix (see https://jsfiddle.net/7ox0hg9L/).
First, the on/off overlay toggle works fine, but if I pan/zoom the image the overlay reappears, even though toggle-off deletes the element from the DOM using parentNode.removeChild().
Second, I can't seem to get the overlay tooltips to work consistently on the first page, and they never appear on the following pages. The tooltip on the radiobutton label works fine on any page though, so I'm not sure why the tooltips on the overlays do not.
Any suggestion would be welcome. Please bear in mind that I am new to javascript. Thanks!
EDIT: iangilman's answer below and his edits on jsfiddle put me back on track, and helped me create the gallery I had in mind. I post here the full solution for those who may need similar features. Thanks Ian!
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset='utf-8'>
<script src="https://cdnjs.cloudflare.com/ajax/libs/openseadragon/2.3.1/openseadragon.min.js"></script>
<style>
body {
margin: 0;
color: #333;
font-family: Helvetica, Arial, FreeSans, san-serif;
background-color: #121621;
}
.openseadragon{
width: 800px;
height: 600px;
border: 1px solid black;
color: #333;
background-color: black;
}
.highlight{
opacity: 0.4;
filter: alpha(opacity=40);
outline: 6px auto #0A7EbE;
background-color: white;
}
.highlight:hover, .highlight:focus{
filter: alpha(opacity=70);
opacity: 0.7;
background-color: transparent;
}
.nav {
cursor: pointer;
display: inline-block;
font-size: 25px;
}
.controls {
text-align: center;
display: table;
background-color: #eee;
table-layout: fixed;
width: 800px;
}
</style>
</head>
<body>
<link rel="stylesheet" href="https://code.jquery.com/ui/1.12.1/themes/smoothness/jquery-ui.css">
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.min.js"></script>
<div class="controls">
<label class="labels"><input id="showOverlays" type="checkbox"><a id="selector" title="">Show overlays</a></label>
<a class="nav previous" title="Previous" id="prv"> < </a>
<a class="nav next" title="Next" id="nxt"> > </a>
</div>
<div id="example-runtime-overlay" class="openseadragon" />
<script type="text/javascript">
var tileSource = {
Image: {
xmlns: "http://schemas.microsoft.com/deepzoom/2008",
Url: "http://openseadragon.github.io/example-images/highsmith/highsmith_files/",
Format: "jpg",
Overlap: "2",
TileSize: "256",
Size: {
Height: "9221",
Width: "7026"
}
}
};
var runtimeViewer = OpenSeadragon({
id: "example-runtime-overlay",
prefixUrl: "openseadragon/images/",
showSequenceControl: true,
sequenceMode: true,
nextButton: "nxt",
previousButton: "prv",
tileSources: [{
tileSource: tileSource,
overlay: [{
id: 'example-overlay',
x: 0.43,
y: 0.47,
width: 0.15,
height: 0.20,
className: 'highlight',
caption: 'Nice painting'
}]
},{
tileSource: tileSource,
overlay: [{
id: 'example-overlay',
x: 0.65,
y: 0.05,
width: 0.12,
height: 0.12,
className: 'highlight',
caption: 'Milton'
}]
}]
});
var page = 0;
runtimeViewer.addHandler("page", function (data) {
page = data.page;
});
$('.next').click(function() {
radio.prop('checked', false);
});
$('.previous').click(function() {
radio.prop('checked', false);
});
var radio = $('#showOverlays')
.prop('checked', false)
.change(function() {
if (radio.prop('checked')) {
var overlay = runtimeViewer.tileSources[page].overlay[0];
var elt = document.createElement("div");
elt.id = overlay.id;
elt.className = overlay.className;
elt.title = "";
$(elt).tooltip({
content: overlay.caption
});
runtimeViewer.addOverlay({
element: elt,
location: new OpenSeadragon.Rect(overlay.x, overlay.y, overlay.width, overlay.height)
});
} else {
var overlay = runtimeViewer.tileSources[page].overlay[0];
var element = document.getElementById(overlay.id);
if (element) {
runtimeViewer.removeOverlay(element);
delete element;
}
}
});
$(function() {
$(document).tooltip();
});
</script>
</body>
</html>
Looks like you're off to a good start!
You're correctly adding the overlays with addOverlay, so you need to remove them with removeOverlay:
runtimeViewer.removeOverlay(element);
For the tooltips, unfortunately OpenSeadragon's event handling can interfere with jQuery, so you'll have to use the OpenSeadragon MouseTracker:
function bindTooltip(elt) {
new OpenSeadragon.MouseTracker({
element: elt,
enterHandler: function(event) {
// Show tooltip
},
exitHandler: function(event) {
// Hide tooltip
}
}).setTracking(true);
}