While there are Qt::ImhDigitsOnly and Qt::ImhFormattedNumbersOnly these seem only limited to decimal-based numbers.
In scientific and technical applications/devices it is not too uncommon to have to enter numbers also in a hexadecimal form. With the existing flags it seems not possible to e.g. tell a virtual keyboard that the current input field needs only 0-9A-E + Enter keys and not one with the complete char layout.
(same is also true for octal and binary, but these can still be used with a decimal digits keyboard, without too much visual clutter)
Would be great if that could be added/enabled somehow.
The Qt::InputMethodHints flags seem not scalable, there is more in the world then Telephone numbers, email addresses and web urls