127 lines
3.5 KiB
Dart
127 lines
3.5 KiB
Dart
library flutter_map_mbtiles_provider;
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import 'dart:io';
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import 'dart:typed_data';
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import 'dart:ui';
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import 'package:flutter/foundation.dart';
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import 'package:flutter/services.dart';
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import 'package:flutter/widgets.dart';
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import 'package:flutter_map/flutter_map.dart';
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// import 'package:flutter_map/src/layer/tile_provider/tile_provider.dart';
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import 'package:path_provider/path_provider.dart';
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import 'package:sqflite/sqflite.dart';
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class MBTilesImageProvider extends TileProvider {
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final String asset;
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final File mbtilesFile;
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Future<Database> database;
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Database _loadedDb;
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bool isDisposed = false;
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MBTilesImageProvider._({this.asset, this.mbtilesFile}) {
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database = _loadMBTilesDatabase();
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}
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factory MBTilesImageProvider.fromAsset(String asset) => MBTilesImageProvider._(asset: asset);
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factory MBTilesImageProvider.fromFile(File mbtilesFile) => MBTilesImageProvider._(mbtilesFile: mbtilesFile);
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Future<Database> _loadMBTilesDatabase() async {
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if (_loadedDb == null) {
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var file = mbtilesFile ?? await copyFileFromAssets();
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_loadedDb = await openDatabase(file.path);
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if (isDisposed) {
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await _loadedDb.close();
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_loadedDb = null;
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throw Exception('Tileprovider is already disposed');
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}
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}
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return _loadedDb;
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}
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@override
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void dispose() {
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if (_loadedDb != null) {
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_loadedDb.close();
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_loadedDb = null;
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}
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isDisposed = true;
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}
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Future<File> copyFileFromAssets() async {
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var tempDir = await getTemporaryDirectory();
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var filename = asset.split('/').last;
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var file = File('${tempDir.path}/$filename');
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var data = await rootBundle.load(asset);
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file.writeAsBytesSync(data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes), flush: true);
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return file;
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}
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@override
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ImageProvider getImage(Coords<num> coords, TileLayerOptions options) {
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var x = coords.x.round();
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var y = options.tms ? invertY(coords.y.round(), coords.z.round()) : coords.y.round();
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var z = coords.z.round();
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return MBTileImage(
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database,
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Coords<int>(x, y)..z = z,
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mbtilesFile?.path ?? asset,
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);
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}
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}
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class MBTileImage extends ImageProvider<MBTileImage> {
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final Future<Database> database;
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final Coords<int> coords;
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final String filePath;
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MBTileImage(this.database, this.coords, this.filePath);
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@override
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ImageStreamCompleter load(MBTileImage key, decode) {
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return MultiFrameImageStreamCompleter(
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codec: _loadAsync(key),
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scale: 1,
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informationCollector: () sync* {
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yield DiagnosticsProperty<ImageProvider>('Image provider', this);
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yield DiagnosticsProperty<ImageProvider>('Image key', key);
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});
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}
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Future<Codec> _loadAsync(MBTileImage key) async {
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assert(key == this);
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final db = await key.database;
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List<Map> result = await db.rawQuery('select tile_data from tiles '
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'where zoom_level = ${coords.z} AND '
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'tile_column = ${coords.x} AND '
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'tile_row = ${coords.y} limit 1');
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final Uint8List bytes = result.isNotEmpty ? result.first['tile_data'] : null;
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if (bytes == null) {
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return Future<Codec>.error('Failed to load tile for coords: $coords');
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}
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return await PaintingBinding.instance.instantiateImageCodec(bytes);
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}
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@override
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Future<MBTileImage> obtainKey(ImageConfiguration configuration) {
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return SynchronousFuture(this);
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}
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@override
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int get hashCode => coords.hashCode;
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@override
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bool operator ==(other) {
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return other is MBTileImage && coords == other.coords && filePath == other.filePath;
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}
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}
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