PropertyHandle :: ReadBuffer - Fill instance buffer from position
The function explicitly fills the buffer instances. the position of the first instance to be read is passed in set_pos0. The function removes all buffer instances located in the buffer and refills the buffer. Passing CURRENT_INSTANCE as next position (default) the buffer reads instances beginning with the current position which has been set by the last Get() or LocateKey() function. When no instance is selected the buffer is filled beginning with the first instance.
When reading the last instances in a collection the buffer might not be filled completely. The number of instances read into the buffer is returned from the function.
Implementation details
- set_pos0
- Position in collection
The position of an instance in a collection depends on the selected index. if the collection is unsorted the position is the only way for accessing the instance.
For sorted collections the position is determined according to the instance key. If is a contradiction between position and key value the position will be ignored.
Special positions are
CUR_INSTANCE (-1) refers to the currently selected instance. If no instance is selected it refers to the first instance.
FIRST_INSTANCE (0) refers to the first instance in a collection according to the selected index (sort order).
FIRST_INSTANCE (0x7fffffff) refers to the last instance in a collection according to the selected index (sort order).
- direction_w
- Direction for positioning
When direction is positive, the operation positions forward. For a negative position, the operation positions backward.
Default: 1