api:dk11:delphi:fmx.gisviewerwnd.tgis_viewerwnd.locate_tgis_point_double_boolean
Table of Contents
TGIS_ViewerWnd.Locate(TGIS_Point; Double; Boolean) method
DK11 for Delphi | FMX.GisViewerWnd.TGIS_ViewerWnd.Locate | Overloads | Constructors | Methods | Properties | Events
Locate a shape that is near _ptg, but is closer than _prec distance.
Available also on: .NET WinForms | Java | ActiveX.
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 locate is called upon active paint operations then result could be null. But Locate and paint process are using the same vector enumerator context.
It is recommended to check InPaint property before calling this Locate.
2020/05/22 01:06