samples:samples:hellodk
Table of Contents
HelloDK sample
Documentation | Samples | HelloDK
Summary
HelloDK - TatukGIS Developer Kernel introductory sample demonstrating core GIS workflows including data loading, layer management, and interactive visualization.
Description
What the sample shows:
- Opening a vector Shapefile (world map) into the GIS viewer
- Switching the viewer interaction mode: Zoom / Drag / Select
- Creating an in-memory editable vector layer with a transparent polygon style
- Building a polygon shape programmatically by adding explicit vertices
- Click-to-select a feature using screen-to-map coordinate conversion
- Spatial proximity search via GIS.Locate to identify shapes near cursor
- Spatial containment query using DE-9IM topology predicates
- SQL WHERE filtering to find shapes with specific attributes
- Full extent zoom and navigation buttons
- Core TatukGIS DK workflow demonstration
This sample illustrates use of:
| Name | Description |
|---|---|
| TGIS_Viewer | Generic map viewer implementation intended to be used through descendants such as TGIS_ViewerWnd and TGIS_ViewerBmp rather than directly. |
| TGIS_ViewerWnd | Main FireMonkey visual control for displaying and interacting with maps in a window. |
| TGIS_Viewer.Open | Open a project. |
| TGIS_Viewer.InvalidateWholeMap | Invalidate whole map. |
| TGIS_Viewer.Lock | Lock the viewer. |
| TGIS_Viewer.Unlock | Unlock the viewer and redraw it. |
| TGIS_Viewer.ScreenToMap | Converts point coordinates from screen coordinates to map coordinates. |
| TGIS_Viewer.Locate | Locates the shape nearest to _ptg that is within _prec. |
| TGIS_Viewer.Add | Add a layer to the Viewer. |
| TGIS_Viewer.Get | Retrieve the layer identified by name. |
| TGIS_LayerVector.DeselectAll | Clears the selection state of all shapes in the layer. |
| TGIS_LayerVector.GetShape | Retrieves a shape by its unique identifier (UID) using the default cursor (0). |
| TGIS_Layer.Name | Layer name. |
| TGIS_Layer.CS | Coordinate Reference System (CRS) assigned to the layer. |
| TGIS_LayerVector.Params | Returns the vector rendering parameters object for the layer. |
| TGIS_ParamsArea | Parameters that are common for area features. |
| TGIS_Shape.MakeEditable | Make the shape editable by materializing mutable shape data when necessary. |
| TGIS_Shape.IsSelected | Shape is selected in the layer. |
| TGIS_Shape.Lock | Locks the shape for batch geometry updates to defer expensive recalculations. |
| TGIS_Shape.Unlock | Unlocks the shape and applies deferred geometry updates. |
| TGIS_Shape.AddPart | Starts a new part in a multipart shape geometry. |
| TGIS_Shape.AddPoint | Adds a 2D vertex to the current part of the shape. |
Code
This sample is available on the following platforms (click to view the source code on GitHub):
2026/07/08 06:04