Table of Contents
Technical description of maps
Since version 6.14 a:Drake renders all maps with the Mapsforge library. Two kinds of maps are supported:
- raster (tile) maps – the map consists of 256×256 pixel images (tiles). Tiles are downloaded from the internet (OpenStreetMap, Mapy.cz, Google, custom source) and saved automatically for off-line use. A prepared off-line map can be used as well.
- Mapsforge vector maps – a
.mapfile describing map objects, rendered on the phone according to the selected theme. They need much less space for large areas. See vector map resources.
Maps are configured in Settings → Maps → Edit map configuration. Changes are stored in map-config.xml (see below); there is no need to edit it by hand.
Where maps are stored
- The data folder is selected in Settings (Internal (device), External (SD card) or Other). By default it is the app's private folder, e.g.
/storage/emulated/0/Android/data/cz.adrake/files. It contains the database,map-config.xmland themapssubfolder with raster tiles. - Vector maps and themes are selected with the system file picker (Storage Access Framework) since 6.14. Files can be stored anywhere on the device or SD card (e.g.
DownloadorDocuments); copying them to the data folder is not necessary. a:Drake remembers the access permission and asks again if it is lost (e.g. after the file was moved).
Raster maps
Each raster layer has its own SQLite database with the .sqlitedb extension (table tiles with columns x, y, z, s, image and table info with the zoom range). The format matches RMaps/BigPlanet SQLite, also used by Locus and produced by Mobile Atlas Creator (MobAC). MobAC always names the file BigPlanet_maps.sqlitedb, rename it according to the layer setting (File/technical name).
A layer with an empty URL is an off-line map – nothing is downloaded, tiles are only read from the database (marked (offline) in the map list).
<file> value | Actual file |
|---|---|
osm/mapnik | <data folder>/maps/osm/mapnik.sqlitedb |
/storage/emulated/0/Locus/mapsOnline/map.sqlitedb | absolute path including extension |
content://… | file selected with the system file picker |
If storage or file of an existing layer is changed, existing tiles are NOT converted.
map-config.xml
map-config.xml is stored in the data folder. A default version (OpenStreetMap, Google Maps, Mapy.cz and Mapsforge vector maps) is created on first start. If the file is broken, a:Drake renames it to .bak and creates a new default one.
| Tag | Description | |||
|---|---|---|---|---|
| aDrake | mandatory envelope | |||
| MapSource | map source, shown as a map source choice in the app | |||
| type | Google … Slippy Map tiles (OSM, Google, Mapy.cz and most others), URL contains {x}, {y}, {z}MapsForge … Mapsforge vector maps |
|||
| name | display name | |||
| language | language of the name; used when it matches the phone language. One name without language should exist as default. | |||
| storage | tile storage, database (one SQLite file per layer) |
|||
| requestHeader | optional additional HTTP request header, e.g. Referer |
|||
| MapType | map layer (any number of basic layers, max. 5 overlays per source) | |||
| mode | basic … base map, one is activeoverlay … overlay (hiking trails etc.), several can be active |
|||
| name | layer name | |||
| file | raster layer: file/technical name of the database vector layer: the .map file |
|||
| themeFile | vector layer: ZIP archive with themes (Elevate, OpenAndroMaps …) | |||
| themes | list of themes found in the ZIP, attribute selected = index of the selected theme (filled in by the app) | |||
| theme | vector layer: older way – path to a single XML theme | |||
| url | tile URL; {x}, {y} = tile coordinates, {z} = zoom, {s} = subdomain character. Empty URL = off-line map. |
|||
| subdomain | characters substituted for {s} (e.g. abc or 0123) |
|||
| invertY | true for sources with inverted Y axis (TMS) |
|||
| defaultZoom | initial zoom when the map is opened for the first time | |||
| minZoom | minimum zoom | |||
| maxAvailZoom | maximum zoom available for download | |||
| maxZoom | maximum zoom | |||
Please respect the terms of use of on-line map providers.