This sample shows how to snap a draggable object to a 20x20 grid.
<div class="easyui-panel" style="position:relative;overflow:hidden;width:500px;height:300px">
<div class="easyui-draggable" data-options="onDrag:onDrag" style="width:100px;height:100px;background:#fafafa;border:1px solid #ccc;">
</div>
</div>
<script>
function onDrag(e){
var d = e.data;
d.left = repair(d.left);
d.top = repair(d.top);
function repair(v){
var r = parseInt(v/20)*20;
if (Math.abs(v % 20) > 10){
r += v > 0 ? 20 : -20;
}
return r;
}
}
</script>