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A linear indicator can be integrated into form elements, such as file uploads, to express a connection between a background ongoing process and individual items. They are ideal for long determinate activities (over 10 seconds).
A circular indicator can be integrated into a button or actionable icon on a ribbon to show a connection between an interaction and a specific item. They are typically used to show when an interaction is not available, such as a repeated click of a button again. They should be used for short, indeterminate activities (between 2-5 seconds).
Don’t Use:
when When the action lasts less than 1 second.
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