I'm not sure if this is a bug or my failure to understand how this works.

I'm using an Input widget for collecting user input and I've set the hintText field to display 'Type a thing here', so the user knows what to do. That works and the hintText is displayed in grey inside my Input. But when the user clicks into the Input and starts typing, the text they type is displayed in black on top of the grey hint text. I would expect the hintText to disappear. Is this something I should be manually controlling, maybe from onChanged? Is there another way to do this? Or is this a bug I should file on GitHub?