Add indefinite snackbar duration

Feature Request

Currently, snackbars time out after a set period of time, which fits with the transient principle in the material design guidelines. The android spec, however, allows the user to display a snackbar for an indefinite amount of time.

I think this feature could be useful to have in the web components. It could still be transient by default, but the user could optionally specify an indefinite length of time. It could be a separate property like:

const snackbar_options = {
    indefinite: true
}

or another value for timeout, like:

const snackbar_options = {
    timeout: null
}

[montoyaaguirre]

This feature has been implemented. If you’re using angular material and you want to open a snackbar that will stay on screen until the next one is displayed, you can use: snackbar.open(“Message”, “Action”, {duration: undefined});

[jwgwarren]

This outcome is just irritating.