[Snackbar] Not visible if keyboard is displayed (touch devices)

[aldo-roman]

Bug:

Snackbar is hidden when the virtual keyboard is opened.
Tested on iOS 11

What is the expected behavior?

Snackbar is placed on the bottom of visible screen, above keyboard

What is the current behavior?

Snackbar is placed on behind keyboard, not visible

What are the steps to reproduce?

Stackblitz Editor: https://stackblitz.com/edit/angular-material2-issue-brodsj

0. Open https://angular-material2-issue-brodsj.stackblitz.io on a touchscreen device with virtual
   keyboard.

Case 1:

1. Tap "Open snackbar" link
2. Keyboard is displayed hidding the snackbar

Case 2:

1. Tap "Open same snackbar" button -> The snackbar is displayed and visible
2. Tap "The placeholder" input field -> Keyboard is displayed hidding the snackbar

What is the use-case or motivation for changing an existing behavior?

We want to notify the user from some action AND request immediate input.

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

Angular 5+

Is there anything else we should know?

Tested on iOS11, Safari

[ttugates]

I am not clear on if this is P0: critical or P5: nice to have..

This affects us and would like it to be higher priority than P5.

[mina-skunk]

Priority seems low, since we lose the ability to use this feature when inputs are visible on iOS devices.

[josephperrott]

It does not seem possible to move the snackbar to a visible location automatically in this situation. It appears that browsers/devices do not provide the open state of an on screen keyboard and also do not alter the size of the page's viewport based on the keyboard taking up space. Because of this it is not possible at this point to determine the new anchor point for the snackbar to reveal from.

[bmtheo]

iOS closes the virtual keyboard when your current input loses focus

In our solution we just did this before opening the snackbar
if (document.activeElement instanceof HTMLElement) { document.activeElement.blur(); }

This workaround is working on iOS 12