Empty ToolTip is shown when you use it for showing reasons why a textField has no

I created a small example that uses a TextField with a DoubleValidator and shows a string in a ToolTip when the textFields acceptableInput property is false.

When you change the bottom/top values of the validator before changing the textfield value you get a short "false negative" validation result. That triggers the ToolTip enter/exit transitions of the material theme to run. But meanwhile the textField gets a valid value and all you see is an empty tootip. 

The wrong order of assigning the bottom/top values of the validator is just used to show the problem so please do not suggest to fix this by using the right order. Thats not what this issue is about.

I am not even sure that this can be considered as a bug, maybe its a feature request to be able to close an ToolTip immediately (stopping all running transitions)