Replace our custom tile pipeline (fetchRemoteTile / _SimpleSemaphore /
exponential backoff) with flutter_map's built-in NetworkTileProvider,
gaining persistent disk cache, ETag revalidation, RetryClient, and
obsolete request aborting for free.
DeflockTileProvider now extends NetworkTileProvider and overrides
getTileUrl() to route through TileType.getTileUrl() (quadkey,
subdomains, API keys). getImageWithCancelLoadingSupport() routes
between two paths at runtime: the common network path (super) when
no offline areas exist, and a DeflockOfflineTileImageProvider for
offline-first when they do.
- Delete tiles_from_remote.dart (semaphore, retry loop, spatial helpers)
- Simplify MapDataProvider._fetchRemoteTileFromCurrentProvider to plain
http.get (only used by offline area downloader now)
- Remove dead clearTileQueue/clearTileQueueSelective from MapDataProvider
- Remove 7 tile fetch constants from dev_config.dart
- TileLayerManager now disposes provider on cache clear and uses actual
urlTemplate for cache key generation
- 9 new tests covering URL delegation, routing, and equality
Closes#87 Phase 2.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
