USER INTERFACE EXECUTION APPARATUS AND USER INTERFACE DESIGNING APPARATUS

The present invention has an object of providing a user interface execution apparatus and a user interface designing apparatus which can estimate the maximum size of a storage area for storing data to be prefetched when a user interface is designed and can present updated data to the user even when the prefetched data is updated after the prefetch. A user interface execution apparatus in the present invention includes a processor to execute a program; and a memory to store the program which, when executed by the processor, performs processes of: transitioning a state of the user interface execution apparatus; issuing a prefetch request for data; storing the data; generating the code from an interface definition and a state transition definition; and selecting, before transitioning the state, data to be prefetched based on a difference between a data obtaining interface to be used in a state before the transitioning and a data obtaining interface to be used in a state after the transitioning.