nepal_map

A fully interactive, customizable Flutter widget for displaying and interacting with the map of Nepal, with district- and province-level selection, theming, markers, heatmaps, and more.

✨ Features

• 🗺️ 77 Districts — All districts of Nepal rendered from bundled GeoJSON
• 🖱️ Selection Modes — Single/multi select for districts and provinces
• 🎨 Full Theming — Configurable colors, per-district/province overrides, tooltip & marker styles
• 🌈 Theme Presets — Built-in light, dark, and province rainbow palettes
• 📍 Markers — Place custom widgets on district centroids or custom coordinates
• 🔥 Heatmaps — Data-driven color rendering with configurable color scales
• 📊 Coverage Layers — Overlay highlighted district groups (e.g., bank branches, delivery zones)
• 🔍 Zoom & Pan — Pinch, scroll wheel, trackpad zoom with constrained boundaries
• 💬 Hover Tooltips — Customizable floating tooltips on hover (desktop/web)
• 📋 Legend Widget — Built-in legend for layers, heatmaps, and selection info
• ⚡ Controller API — Full programmatic control over selection, zoom, markers, layers, and heatmaps
• 🎯 Custom Assets — Load your own GeoJSON for simplified or updated maps

🛠️ Getting Started

Add this to your pubspec.yaml:

dependencies:
  nepal_map: ^<latest_version>

Then run:

flutter pub get

💡 Usage

Basic

Import the package:

import 'package:nepal_map/nepal_map.dart';

Create a controller and use the widget:

final controller = NepalMapController(mode: NepalSelectionMode.singleDistrict);

NepalMapWidget(
  controller: controller,
  onDistrictTap: (district) {
    print('Tapped ${district.name}, province ${district.provinceNumber}');
  },
)

Selection Modes

// Single district selection
NepalMapController(mode: NepalSelectionMode.singleDistrict)

// Multi district selection
NepalMapController(mode: NepalSelectionMode.multiDistrict)

// Single province selection
NepalMapController(mode: NepalSelectionMode.singleProvince)

// Multi province selection
NepalMapController(mode: NepalSelectionMode.multiProvince)

// No selection (display only)
NepalMapController(mode: NepalSelectionMode.none)

Read selection state:

controller.selectedDistricts;        // Set<String> of district ids
controller.selectedProvinces;        // Set<int> of province numbers
controller.isDistrictSelected('kathmandu');
controller.isProvinceSelected(3);

Programmatic selection:

controller.selectDistrict('kathmandu');
controller.selectProvince(3);
controller.clearSelection();
controller.setMode(NepalSelectionMode.multiProvince);

🎨 Theming

Quick color customization:

NepalMapWidget(
  controller: controller,
  theme: NepalMapTheme.fromColors(
    baseColor: Colors.blue[50]!,
    selectedColor: Colors.blue[700]!,
    hoverColor: Colors.blue[200]!,
    borderColor: Colors.blue[300]!,
    borderWidth: 1.5,
  ),
)

Per-province colors:

NepalMapWidget(
  controller: controller,
  theme: NepalMapTheme(
    colors: NepalMapColors(
      provinceColors: NepalMapThemePresets.provinceRainbow,
    ),
  ),
)

Per-district colors with custom tooltip:

NepalMapWidget(
  controller: controller,
  theme: NepalMapTheme(
    colors: NepalMapColors(
      districtColors: {
        'kathmandu': Colors.amber,
        'lalitpur': Colors.green[200]!,
        'bhaktapur': Colors.pink[200]!,
      },
    ),
    tooltipStyle: TooltipStyle(
      backgroundColor: Colors.black87,
      borderRadius: 12,
      elevation: 8,
      padding: EdgeInsets.symmetric(horizontal: 14, vertical: 8),
    ),
    markerStyle: MarkerStyle(
      color: Colors.deepOrange,
      icon: Icons.place,
    ),
  ),
)

📍 Markers

Place markers on district centroids:

controller.addMarkers([
  MapMarker(
    id: 'kathmandu',
    districtId: 'kathmandu',
    size: 28,
    child: Icon(Icons.location_pin, color: Colors.red),
  ),
  MapMarker(
    id: 'pokhara',
    districtId: 'kaski',
    size: 24,
    child: Icon(Icons.place, color: Colors.purple),
  ),
]);

Place markers at custom coordinates:

controller.addMarker(MapMarker(
  id: 'custom',
  position: Offset(83.9856, 27.7172), // lng, lat
  child: Icon(Icons.star, color: Colors.amber),
));

🔥 Heatmaps

Data-driven color rendering:

controller.setHeatmap(HeatmapConfig(
  dataMap: {
    'kathmandu': 177.0,
    'lalitpur': 29.0,
    'bhaktapur': 30.0,
    'pokhara': 10.0,
    // ... more districts
  },
  label: 'Population (thousands)',
  minValue: 0,
  maxValue: 200,
  colors: [
    Colors.green[100]!,
    Colors.green[400]!,
    Colors.orange[400]!,
    Colors.red[400]!,
  ],
));

📊 Coverage Layers

Overlay highlighted district groups:

controller.addCoverageLayer(CoverageLayer(
  id: 'bank_branches',
  name: 'Bank Branches',
  districtIds: ['kathmandu', 'lalitpur', 'bhaktapur', 'chitwan'],
  color: Colors.blue,
  opacity: 0.4,
));

controller.addCoverageLayer(CoverageLayer(
  id: 'delivery_zones',
  name: 'Delivery Zones',
  districtIds: ['kathmandu', 'lalitpur', 'bhaktapur'],
  color: Colors.orange,
  opacity: 0.35,
));

🔍 Zoom & Pan

controller.zoomIn();
controller.zoomOut();
controller.resetView();
controller.fitToScreen();

// Custom zoom range
NepalMapController(minScale: 0.5, maxScale: 10.0);

📋 Legend Widget

Display a legend alongside your map:

Row(
  children: [
    Expanded(
      child: NepalMapWidget(controller: controller),
    ),
    SizedBox(
      width: 200,
      child: LegendWidget(
        controller: controller,
        title: 'Legend',
        showLayers: true,
        showHeatmap: true,
        showSelection: true,
      ),
    ),
  ],
)

🖱️ Hover Tooltips (Desktop/Web)

NepalMapWidget(
  controller: controller,
  showHoverTooltip: true,
  onDistrictHover: (district) {
    if (district != null) {
      print('Hovering ${district.name}');
    }
  },
  tooltipBuilder: (context, district) {
    return Container(
      padding: EdgeInsets.all(8),
      color: Colors.black87,
      child: Text(
        '${district.name}\nHQ: ${district.headquarter}',
        style: TextStyle(color: Colors.white),
      ),
    );
  },
)

🌐 Demo

Check out the example app in this repository for a complete demo with all features:

cd example
flutter pub get
flutter run

📦 API Reference

NepalMapWidget

Property	Type	Default	Description
controller	NepalMapController	required	Controls selection, zoom, markers, layers
theme	NepalMapTheme?	null	Colors, tooltip, and marker styles
onDistrictTap	Function(NepalDistrict)	null	Called on district tap
onProvinceTap	Function(int, List<NepalDistrict>)	null	Called on province selection
onDistrictHover	Function(NepalDistrict?)	null	Called on hover (desktop/web)
showHoverTooltip	bool	true	Show built-in hover tooltip
tooltipBuilder	Widget Function(BuildContext, NepalDistrict)	null	Custom tooltip widget
enablePan	bool	true	Enable drag panning
enableZoom	bool	true	Enable pinch/scroll zoom
boundaryMargin	EdgeInsets	EdgeInsets.zero	How far past bounds to pan
assetPath	String?	null	Custom GeoJSON asset path
loadingBuilder	WidgetBuilder?	null	Custom loading widget
errorBuilder	Widget Function(BuildContext, Object)?	null	Custom error widget

NepalMapController

Method	Description
selectDistrict(id)	Programmatically select a district
selectProvince(number)	Programmatically select a province
clearSelection()	Clear all selection
setMode(mode)	Switch selection mode
zoomIn() / zoomOut()	Zoom in/out
resetView() / fitToScreen()	Reset zoom and pan
addMarker(marker)	Add a marker
addMarkers(list)	Add multiple markers
removeMarker(id)	Remove a marker
clearMarkers()	Clear all markers
setHeatmap(config)	Set heatmap configuration
clearHeatmap()	Clear heatmap
addCoverageLayer(layer)	Add a coverage layer
removeCoverageLayer(id)	Remove a coverage layer
clearCoverageLayers()	Clear all layers

NepalMapTheme

Property	Type	Description
colors	NepalMapColors	Color scheme for the map
tooltipStyle	TooltipStyle	Hover tooltip appearance
markerStyle	MarkerStyle	Default marker appearance

NepalMapColors

Property	Type	Description
baseColor	Color	Default district fill
selectedColor	Color	Selected district fill
hoverColor	Color	Hovered district fill
disabledColor	Color	Disabled district fill
borderColor	Color	District border color
borderWidth	double	District border width
provinceColors	Map<int, Color>?	Per-province color overrides
districtColors	Map<String, Color>?	Per-district color overrides

🤝 Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.

📄 License

Licensed under the MIT License.