map_slippy_fetcher(3)

map::slippy::fetcher(3tcl)     Mapping utilities    map::slippy::fetcher(3tcl)

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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  ?0.4?

       ::map::slippy::fetcher fetcherName levels url

       fetcherName levels

       fetcherName tileheight

       fetcherName tilewidth

       fetcherName get tile donecmd

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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 ei-
              ther 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

tcllib                                0.4           map::slippy::fetcher(3tcl)