System and method for detecting a scrolling event during a client display update

A method for detecting a scrolling event and for updating a display, the method comprising:

• transmitting information from a first computer to a second computer over a network,
• storing, at the first computer, a destination array including a plurality of pixels corresponding to a present set of data on a display of the second computer, the destination array including a plurality of rows and a pixel location for each pixel;
• storing, at the first computer, a source array including a plurality of pixels corresponding to an expected set of data to be provided on the display of the second computer after a scrolling event is performed at the second computer, the source array including a plurality of rows and a pixel location for each pixel;
• determining hash values of pixel pairs for the plurality of pixels at each pixel location of the destination array;
• determining hash values of pixel pairs for the plurality of pixels at each pixel location of the source array;
• determining a final scroll offset between the pixels in the destination array and the pixels in the source array based on the hash values of the pixel pairs for the destination array and on the hash values of the pixel pairs for the source array;
• transmitting, from the first computer, pixels indicative of the expected set of data to the second computer based on the final scroll offset such that the second computer provides the expected set of data on the display thereof when the scrolling event is performed;
• grouping the pixel locations with equal hash values of the destination array into buckets generating a count for each bucket prior to determining the scroll offset;
• determining whether the count for each bucket is equal to or greater than a first predetermined value and is equal to or less than a second predetermined value;
• and
• comparing, for each count that is equal to or greater than the first predetermined value and that is equal to or less than the second predetermined value, rows of the source array to rows of the destination array to determine if one or more of the rows of the source array are equal to one or more of the rows of the destination array,
• wherein the second predetermined value corresponds to a resolution in terms of determining the pixel offset during the scrolling event.

An apparatus for updating a display based on a scrolling event, the apparatus comprising:

• a first computer configured to receive pixels indicative of an expected set of data from a second computer that are based on a final scroll offset for providing the expected set of data on a display thereof when a scrolling event is performed, the second computer being configured to (i) store a destination array including a plurality of pixels corresponding to a present set of data on a display of the second computer, the destination array including a plurality of rows and a pixel location for each pixel, (ii) store a source array including a plurality of pixels corresponding to an expected set of data to be provided on the display of the second computer after a scrolling event is performed at the second computer, the source array including a plurality of rows and a pixel location for each pixel, (iii) determine hash values of pixel pairs for the plurality of pixels at each pixel location of the destination array, (iv) determine hash values of pixel pairs for the plurality of pixels at each pixel location of the source array, (v) determine the final scroll offset between the pixels in the destination array and the pixels in the source array based on the hash values of the pixel pairs for the destination array and on the hash values of the pixel pairs for the source array, (vi) group the pixel locations with equal hash values of the destination array into buckets, (vii) generate a count for each bucket prior to determining the scroll offset, (viii) determine whether the count for each bucket is equal to or greater than a first predetermined value and is equal to or less than a second predetermined value, and (ix) compare, for each count that is equal to or greater than the first predetermined value and that is equal to or less than the second predetermined value, rows of the source array to rows of the destination array to determine if one or more of the rows of the source array are equal to one or more rows of the destination array, wherein the second predetermined value corresponds to a resolution in terms of determining the pixel offset during the scrolling event.