Toast is showed in the page top position also if is not visible

### Issue type

**I'm submitting a ...** (check one with "x")

* [ x ] bug report
* [ ] feature request

### Issue description
Show the toast message in the top of the VISIBLE page.

**Current behavior:**

Go in a page with a lot of content, that you need to scroll down, and then show a toast. The toast is showed in the top of the page,
also if it is not visible

**Expected behavior:**

The toast is showed in the visible top position of the page.