Simple example of how you can display a "spinner lookalike" using Tableviewer:
BLOCKS
note that I have it set to only respond to a radio button selection.
CSS
table,
td {
border: 0px;
background-color: #fff;
font-weight: 400;
font-size: 1.2em;
}
input[type=radio] {
transform: scale(1.5);
}
body>table {
border-collapse: separate;
border-radius: 15px 15px;
}
td:first-child {
border-radius: 15px 0 0 15px;
}
td:last-child {
border-radius: 0 15px 15px 0;
}
SCREEN
You could combine this with a suitable dialog extension to get the modal/overlay effect



