Finds the first shape in layer. Will use RTree if available.
// Java public TGIS_Shape FindFirst();
// Oxygene public function FindFirst : TGIS_Shape; virtual;
|TGIS_Shape||Shape itself or nil.|
Use this method to find to the first shape in the layer matching given criteria. Using _query param we can narrow the result of the shape searching down to the minimum. This should speed up our process of locating a desired shape.
To locate a shape, simply choose an existing layer and use FindFirst method of with a proper extent and a SQL query as a WHERE clause.