map::slippy::fetcher(3tcl) Mapping utilities map::slippy::fetcher(3tcl)______________________________________________________________________________NAME
map::slippy::fetcher - Accessing a server providing tiles for slippy-
based maps
SYNOPSIS
package require Tcl 8.4
package require Tk 8.4
package require img::png
package require map::slippy
package require map::slippy::fetcher ?0.2?
::map::slippy::fetcher fetcherName levels url
fetcherName levels
fetcherName tileheight
fetcherName tilewidth
fetcherName get tile donecmd
_________________________________________________________________DESCRIPTION
This package provides a class for accessing http servers providing
tiles for slippy-based maps.
API
::map::slippy::fetcher fetcherName levels url
Creates the fetcher fetcherName and configures it with the num‐
ber of zoom levels supported by the tile server, and the url it
is listening on for tile requests.
The result of the command is fetcherName.
METHODS
fetcherName levels
This method returns the number of zoom levels supported by the
fetcher object, and the tile server it is accessing.
fetcherName tileheight
This method returns the height of tiles served, in pixels.
fetcherName tilewidth
This method returns the width of tiles served, in pixels.
fetcherName get tile donecmd
This is the main method of the fetcher, retrieving the image for
the specified tile. The tile identifier is a list containing
three elements, the zoom level, row, and column number of the
tile, in this order.
The command refix donecmd will be invoked when the fetcher
either knows the image for the tile or that no image will forth‐
coming. It will be invoked with either 2 or 3 arguments, i.e.
[1] The string set, the tile, and the image.
[2] The string unset, and the tile.
These two possibilities are used to either signal the image for the
tile, or that the tile has no image defined for it.
REFERENCES
[1] http://wiki.openstreetmap.org/wiki/Main_Page
KEYWORDS
http, location, map, server, slippy, tile, url, zoom
map 0.2 map::slippy::fetcher(3tcl)
