The change-value signal is emitted when a scroll action is performed on a range. It allows an application to determine the type of scroll event that occurred and the resultant new value. The application can handle the event itself and return true to prevent further processing. Or, by returning false, it can pass the event to other handlers until the default GTK+ handler is reached.
The value parameter is unrounded. An application that overrides the change-value signal is responsible for clamping the value to the desired number of decimal digits; the default GTK+ handler clamps the value based on round_digits.
It is not possible to use delayed update policies in an overridden change-value handler.