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 .map file 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.xml and the maps subfolder 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. Download or Documents); 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 active `overlay` … 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.