ECLPSEvent Class

ECLPSEvent objects are passed to ECLListener objects when the presentation space has been updated. This event object represents the presentation space update event and contains information about the update.

There are two sets of functions an application can use to determine the region of the presentation space which was updated. The GetStart() and GetEnd() methods return a linear position indicating the starting position and ending position of the update region in the presentation space. Linear addressing starts at 1 for the upper-left-most character and proceeds left-to-right wrapping from row to row. A corresponding set of functions (GetStartRow, GetStartCol, GetEndRow, GetEndCol) return the same information in row/column coordinates.

The update region includes all PS characters from the starting character to the ending character (inclusive). If the start and end position are not on the same row then the update region wraps from the end of one row to the first column of the next row. Note that the update region is (generally) not rectangular. If the starting position is greater than the ending position, the update region starts at the starting position, wraps from the last character of the screen to the first, and continues to the ending position.

Note that the update region may encompass more than the actual changed portion of the presentation space, but it is guaranteed to cover at least the changed area. When multiple PS updates occur in a short period of time the changes may be aggregated into a single event in which the update region spans the sum of all the updates.