Microsoft granted patent for double-click
"A method and system are provided for extending the functionality of application buttons on a limited resource computing device. Alternative application functions are launched based on the length of time an application button is pressed. A default function for an application is launched if the button is pressed for a short, i.e., normal, period of time.

"An alternative function of the application is launched if the button is pressed for a long, (e.g., at least one second), period of time. Still another function can be launched if the application button is pressed multiple times within a short period of time, e.g., double click."

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