When to use different Android toast durations?

Question

I'm making an Android app and I'm having difficulty determining what duration of 'Toast' I should use.

I'm currently popping up a 'Toast' for an error message which is rather short. I also know I have to take into consideration that the toast often blocks important UI elements which the user may wish to interact with and a long toast may become frustrating. I also have to make sure the toast isn't too short for an important event or the user may not notice it.

I skimmed through the Android documentation and couldn't find much.

Is there an approximate guideline for this?

Answer 1

First thing to consider while designing toast is that it should contain few words or one line of text because it is going to visible on screen for some definite time and will disappear without any user interaction.

Snackbars should contain a single line of text directly related to the operation performed.

Google MD guidelines wrote above line for snacker but I believe it is equally important for toast also.

Try to keep in mind about average reading speed of human which may vary geographically. According to this articlein dailymail.co.uk:

The average speed for adults is 300 words a minute

which means 5 words per second (Now, this looks challenging to me but people in UK might be comfortable with 5words/s, also reading novel or news article is different that a small message as user environment may be totally different). Mobiles are used in environment where people’s attention is split, so they will definitely take more than a second to read and interpret 5 words (If we consider UK's case). Also consider there will be people who take more time than average, they may read only 3 or four words per second. Your design should consider worst case. It’s not possible for me to provide any bottomline but based on your target audience you can run a small research to test your actual toast message.

If your are planning to use snack-bar which has some action to do (e.g. : undo action ) its better to keep it on screen until user interact with it or touch any other area on screen.

Answer 2

The dimension specs are in the Material Design Guidelines: https://www.google.com/design/spec/components/snackbars-toasts.html#snackbars-toasts-usage

Answer 3

2 factors that come to mind would be

1-the length of your message. The message should be visible long enough to be able to be read at comprehended at a comfortable pace.

2-the urgency of the message. of course if its more urgent it should be on for a longer time. also it could be a persistent message. meaning the user has to actively dismiss it to close it.

Answer 4

This would be similar to the issue of type on screen times for motion design. The rule of thumb generally is. The type/message should stay on screen long enough for the user to read it three times comfortably. Give them an ok button to dismiss it too so they can remove it if they finish sooner.