In Mapbox, this example works on a PC but not on a touchscreen Android/iPhone/iPad
https://www.mapbox.com/mapbox.js/example/v1.0.0/opacity/
Is there a simple change to the code below to make it work on mobile devices?
==================
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Opacity control</title>
<meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
<script src='https://api.mapbox.com/mapbox.js/v2.4.0/mapbox.js'></script>
<link href='https://api.mapbox.com/mapbox.js/v2.4.0/mapbox.css' rel='stylesheet' />
<style>
body { margin:0; padding:0; }
#map { position:absolute; top:0; bottom:0; width:100%; }
</style>
</head>
<body>
<style>
.ui-opacity {
background:#FFF;
position:absolute;
left:10px;
top:70px;
height:200px;
width:28px;
border:1px solid rgba(0,0,0,0.4);
border-radius:3px;
z-index:1000;
}
.ui-opacity .handle {
position:absolute;
background:#404040;
left:0;
top:20px;
width:26px;
height:10px;
border-radius:1px;
cursor:pointer;
cursor:ns-resize;
}
.ui-opacity .handle:hover {
background:#303030;
}
</style>
<div id='map'></div>
<div id='control' class='ui-opacity'>
<div id='handle' class='handle'></div>
</div>
<script>
L.mapbox.accessToken = 'AAAAAAAA';
var handle = document.getElementById('handle'),
start = false,
startTop;
var map = L.mapbox.map('map', 'mapbox.emerald')
.setView([43.6654, -79.4775], 14);
var overlay = L.mapbox.tileLayer('aibram.Aerial', {
zIndex: 2
})
.addTo(map);
document.onmousemove = function(e) {
if (!start) return;
// Adjust control.
handle.style.top = Math.max(-5, Math.min(195, startTop + parseInt(e.clientY, 10) - start)) + 'px';
// Adjust opacity.
overlay.setOpacity(1 - (handle.offsetTop / 200));
};
handle.onmousedown = function(e) {
// Record initial positions.
start = parseInt(e.clientY, 10);
startTop = handle.offsetTop - 5;
return false;
};
document.onmouseup = function(e) {
start = null;
};
</script>
</body>
</html>
