How to show the spinning wheel only in the active textbox?

I use angular 5, that is my code I have N textboxes

```html
<div class="input-group-addon" style="background-color: #fff !important" *ngIf="searching "><span><i class="fa fa-spinner fa-spin"></i></span></div>
```

![show Picture](https://i.stack.imgur.com/EF5lF.png)