README

Delphi GeoMap Component

A pure Delphi VCL component for displaying geographic maps with markers, country highlighting, and interactive features.

Features

✅ Zero Dependencies - Pure Delphi, no external libraries
✅ GeoJSON Support - Loads standard GeoJSON map data
✅ Map Projections - Mercator and Equirectangular
✅ Markers - Add markers by coordinates or country code
✅ Interactive - Click, hover, zoom, pan
✅ Customizable - Colors, borders, events
✅ Lightweight - Fast native rendering

Quick Start

Installation

Step 1: Compile the Runtime Package

1. Open Delphi IDE
2. Navigate to: Packages/GeoMapComponents.dpk
3. Right-click the project and select Compile
4. Wait for "Compile successful" message
5. Close this package (you're done with it)

Step 2: Install the Design-Time Package

1. Navigate to: Packages/GeoMapComponentsDesign.dpk
2. Right-click the project and select Install
3. You should see a message: "Package GeoMapComponentsDesign has been installed"
4. The component will appear in the Tool Palette under "GeoMap" category

Step 3: Add Source to Library Path

1. Tools → Options → Language → Delphi → Library
2. Click "..." next to Library Path
3. Add: <YourPath>\Delphi GeoMap Component\Source
4. Click OK

Basic Usage

procedure TForm1.FormCreate(Sender: TObject);
begin
  // Load world map
  GeoMap1.LoadMapFromFile('world.geojson');
  
  // Add markers
  GeoMap1.AddMarker(40.7128, -74.0060, 'New York');
  GeoMap1.AddMarker(51.5074, -0.1278, 'London');
  
  // Highlight countries
  GeoMap1.SetCountryColor('usa', clRed);
  GeoMap1.SetCountryColor('gbr', clBlue);
end;

Component Properties

Component Methods

Map Loading

• LoadMapFromFile(FileName: string) - Load GeoJSON from file
• LoadMapFromJSON(JSON: string) - Load GeoJSON from string

Markers

• AddMarker(Lat, Lon: Double; Caption: string): TGeoMarker - Add marker by coordinates
• ClearMarkers - Remove all markers

Navigation

• ZoomIn - Increase zoom level
• ZoomOut - Decrease zoom level
• ResetView - Reset to default view
• CenterOn(Lat, Lon: Double) - Center map on coordinates
• CenterOnCountry(CountryCode: string) - Center on country

Country Operations

• SetCountryColor(CountryCode: string; Color: TColor) - Set country fill color
• SetCountryValue(CountryCode: string; Value: Double) - Set country data value
• FindCountryAt(X, Y: Integer): TGeoCountry - Get country at screen position

Coordinate Conversion

• LatLonToScreen(Point: TGeoPoint): TPointF - Convert geo to screen coordinates
• ScreenToLatLon(Point: TPointF): TGeoPoint - Convert screen to geo coordinates

Events

• OnMarkerClick(Sender: TObject; Marker: TGeoMarker) - Fired when marker is clicked
• OnCountryClick(Sender: TObject; Country: TGeoCountry) - Fired when country is clicked

File Structure

Delphi GeoMap Component/
????????? Packages/
???   ????????? GeoMapComponents.dpk        # Runtime package
???   ????????? GeoMapComponentsDesign.dpk  # Design-time package
????????? Ressources/
???   ????????? world.geojson               # World map data
????????? Samples/
???   ????????? BasicMapDemo/               # Basic usage example
????????? Source/
???   ????????? GeoMap.Types.pas            # Core data types
???   ????????? GeoMap.Projection.pas       # Map projections
???   ????????? GeoMap.Data.pas             # GeoJSON parser
???   ????????? GeoMap.Markers.pas          # Marker system
???   ????????? GeoMap.VCL.pas              # Main VCL component
???   ????????? GeoMap.VCL.Register.pas     # IDE registration
????????? demo.png                        # Screenshot
????????? README.md                       # This file
????????? USAGE_GUIDE.md                  # Detailed usage guide

GeoJSON Format

The component uses standard GeoJSON FeatureCollection format:

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "shortName": "usa",
        "name": "United States"
      },
      "geometry": {
        "type": "MultiPolygon",
        "coordinates": [[[[lon, lat], ...]]]
      }
    }
  ]
}

Contributing

Contributions are welcome! If you have suggestions or bug fixes, please fork the repository and submit a pull request.

Made with ❤️ using Delphi RAD Studio