flutter_mapstyler 0.1.1

Renders mapstyler_style types on flutter_map — the bridge between format-independent cartographic styles and Flutter map visualization.

flutter_mapstyler

flutter_mapstyler renders mapstyler_style styles on top of flutter_map.

It is the rendering bridge in this workspace:

• mapstyler_style defines format-independent style, rule, symbolizer, filter, expression, and geometry types.
• flutter_mapstyler evaluates those types against feature data.
• flutter_map receives the final Flutter widgets and layers.

Status

The package currently supports:

• rule selection by ScaleDenominator
• expression evaluation for literal, property, case, step, interpolate, and selected argument functions
• filter evaluation for comparison, logical, spatial, and distance filters
• rendering for FillSymbolizer, LineSymbolizer, MarkSymbolizer, IconSymbolizer, TextSymbolizer, and RasterSymbolizer
• optional tap and long-press callbacks per rendered feature

The package deliberately does not parse GeoJSON itself. Input data is expected as StyledFeature objects using the Geometry model from mapstyler_style.

Installation

dependencies:
  flutter_mapstyler: ^0.1.1

Core Types

• StyledFeature: a renderable feature with id, geometry, and properties
• StyledFeatureCollection: a typed wrapper used by StyleRenderer.renderStyle
• StyleRenderer: converts style rules or symbolizers into flutter_map widgets

Example

import 'package:flutter_map/flutter_map.dart';
import 'package:flutter_mapstyler/flutter_mapstyler.dart';
import 'package:latlong2/latlong.dart';
import 'package:mapstyler_style/mapstyler_style.dart';

final style = Style(
  rules: [
    Rule(
      name: 'water',
      filter: const ComparisonFilter(
        operator: ComparisonOperator.eq,
        property: LiteralExpression('class'),
        value: LiteralExpression('water'),
      ),
      symbolizers: const [
        FillSymbolizer(
          color: LiteralExpression('#4da6ff'),
          fillOpacity: LiteralExpression(0.7),
        ),
      ],
    ),
    Rule(
      name: 'cities',
      symbolizers: const [
        TextSymbolizer(
          label: FunctionExpression(PropertyGet('name')),
          color: LiteralExpression('#1f2937'),
          size: LiteralExpression(14.0),
        ),
      ],
    ),
  ],
);

const features = StyledFeatureCollection([
  StyledFeature(
    id: 'lake-1',
    geometry: PolygonGeometry([
      [
        (13.35, 52.48),
        (13.50, 52.48),
        (13.50, 52.56),
        (13.35, 52.56),
        (13.35, 52.48),
      ],
    ]),
    properties: {'class': 'water'},
  ),
  StyledFeature(
    id: 'city-1',
    geometry: PointGeometry(13.405, 52.52),
    properties: {'name': 'Berlin'},
  ),
]);

final renderer = StyleRenderer();

FlutterMap(
  options: const MapOptions(
    initialCenter: LatLng(52.52, 13.405),
    initialZoom: 10,
  ),
  children: renderer.renderStyle(
    style: style,
    features: features,
    onFeatureTap: (feature) {
      print('Tapped: ${feature.id}');
    },
  ),
);

Rendering Model

• renderStyle preserves rule order and emits one or more flutter_map widgets per matching symbolizer.
• renderRule is useful when you already selected a single rule elsewhere.
• symbolizerToLayer is useful for custom rendering pipelines or targeted tests.

Raster Input Conventions

Raster rendering is driven by feature properties:

• Tile rasters: set urlTemplate, optionally fallbackUrl, additionalOptions, subdomains, tms, minZoom, maxZoom, minNativeZoom, maxNativeZoom
• Overlay rasters: use an EnvelopeGeometry plus one of image, url, or asset

Development

From the repository root:

docker build --target flutter-analyze .
docker build --target flutter-test .
docker build --target flutter-coverage-check --no-cache-filter flutter-coverage --progress=plain .

Related Docs

• Architecture notes
• Workspace README