Knowledge Base



KB10431 - ZoomSelect operations using a circle, rectangle, polygon, or line.

With the DK it is possible to zoom to a map extent (to show all features within the extent area) defined using a selection circle, polygon, line or rectangle. Such custom zoom operations must be coded by the DK developer, though it is not difficult, requiring only a few minutes. The procedure is:

  • Draw the circle, rectangle, etc.
  • Select a layer based on drawn object extent.
  • Parse the layer to check if it is within the circle, polygon, etc., using the DK function shape.IsInsideCircle, shape.IsInsidePolygon, etc.
  • Mark any shape meeting this criteria as selected.

If the layer is large and there is a need to limit the size of data to be parsed, this can be done by loosely defining the portion of the layer to be parsed using an extent.

Starting with the DK v.8 release, the DK (and TatukGIS Editor) offers far greater possibilities in the area of geometric querying via support for the Dimensionally Extended 9 Intersection Model (DE-9IM). The DE-9IM spatial querying features work with both shapefile layers and SQL database layers. Refer to the DK Guide for more information about the DE-9IM.

Created: November 21, 2003, Modified: July 30, 2015