According to Apple, a host device, such as a personal computer, is shut down only after a client device (such as a portable personal media player) having a client device shutdown condition (such as a media player battery is fully charged) is satisfied. Such conditions include recharging a media player battery and completing transferring data files between host device and media player.

Here's Apple's summary of the invention: "A method, computer program product, and consumer product for shutting down a host device connected to a client device only when a client device shutdown condition is satisfied. In one embodiment, the host device is a personal computer and the client device is a portable personal media player having a rechargeable battery unit. A user can select that the personal computer can only be shutdown if the media player rechargeable battery unit is fully recharged.

"In another embodiment, computer program product executable by a processor unit for shutting down a host device connected to a client device is disclosed that includes computer code for shutting down the host device only when a client device shutdown condition is satisfied and computer readable medium for storing the computer code.

"In yet another embodiment, A consumer electronic product having a host portion and a client portion is disclosed wherein in order to shut down the host portion, a client portion shutdown condition must be satisfied."

The inventor is Michael M. Lee. The graphic below shows a system in accordance with an embodiment of the invention.