Abstract: An electronic device provides, to a display, data to present a user interface that includes a plurality of user interface objects, and a current focus on a first user interface object. While the display is presenting the user interface, the electronic device receives an input that corresponds to a movement of a contact across on a touch-sensitive surface. The electronic device, in response to receiving the input and in accordance with a determination that a first axis is a dominant axis, moves the current focus along the first axis by a first amount and along the second axis by a second amount. The amount of movement of the current focus along the second axis is reduced to a first non-zero amount by a scaling factor that is based on one or more inputs received prior to receiving the input.

Abstract: In an oil field fracing operation, a direct fire heater is provided that is mobile and self-contained on a trailer chassis. The direct fire heater has the maximum heat exchange possible between a burning gas and the fracing fluid by direct contact therewith. Recirculation is provided to maintain the fracing fluid at the desired temperature. A stack for the direct fire heater is removable for movement from one frac job or frac water heating site to another. Pellets in the stack helps insure a more complete heat exchange between the fracing fluid and the burning gas.