api:dk11:delphi:gisviewer.tgis_viewer.locate_tgis_point_double_boolean
Table of Contents
TGIS_Viewer.Locate(TGIS_Point; Double; Boolean) method
DK11 for Delphi | GisViewer.TGIS_Viewer.Locate | Overloads | Constructors | Fields | Methods | Properties | Events
Locate a shape that is near _ptg, but is closer than _prec distance.
Syntax
Implements IGIS_Viewer.Locate.
// Delphi public function Locate( const _ptg : TGIS_Point; const _prec : Double; const _visible : Boolean ) : TGIS_ShapeAbstract; overload;
// C++ Builder public: TGIS_ShapeAbstract* Locate( TGIS_Point* const _ptg, const double _prec, const bool _visible ) /* overload */;
Parameters
| Name | Type | Description |
|---|---|---|
| _ptg | TGIS_Point | reference point /searching point/ |
| _prec | Double | precision /not a longer distance than/; for points inside the polygon (if _prec >= 0) the distance will be multiply by 0.95 (to prefer points inside the polygon) but will not be bigger then _prec; for point distance will be multiplied by 0.9 to prefer points over lines and polygons; precision is express in map units |
| _visible | Boolean | if true the only visible shapes will be evaluated; shapes turned of by query of hidden will be ignored |
Result
| Type | Description |
|---|---|
| TGIS_ShapeAbstract | Located shape or nil |
Remarks
To improve performance sections visibility can be used to choose layer to call its Locate method. Only visible shapes will be evaluated.
If no shape is found on a layer, the searcher takes into account labels registered by the allocator (by extent). In order to disable this behavior, _visible must be set to False.
References
2022/11/30 19:19