Hello,
I'm trying to set up my own map app using OSM data, mapnik + PostGIS to render
map, mod_tile to serve tiles and OpenLayers for map display. Everything works
fine, except I cannot restrict viewable map area in OpenLayers. I want user to
see only area of one city, and not to zoom out outside it.
So I have downloaded OSM XML file with map of requested area, loaded it to
PostGIS with command like this:
osm2pgsql -d some-db -p some-prefix -U some-user -H localhost
/neuromap/trunk/data/wroclaw-map.osm -c -E 900913 -b
16.8188,50.9974,17.2235,51.2065
(BTW: data is loaded to PostGIS but osm2pgsql says:
StartElement: Unknown element name: bounds
EndElement: Unknown element name: bounds - maybe this is a problem?)
I create OpenLayers map as follows:
var mapnikLayer = new OpenLayers.Layer.OSM("world", "http://some-url...";);
var mapOptions = {
controls:[
new OpenLayers.Control.PanZoomBar(),
new OpenLayers.Control.Permalink(),
new OpenLayers.Control.ScaleLine(),
new OpenLayers.Control.OverviewMap(),
new OpenLayers.Control.Permalink('permalink'),
new OpenLayers.Control.MousePosition(),
new OpenLayers.Control.KeyboardDefaults(),
new OpenLayers.Control.MouseDefaults()
],
maxExtent: new OpenLayers.Bounds(1863611,6614478,1924760,6660340),
maxResolution: 0.6,
units: 'm',
//numZoomLevels: 19,
projection: new OpenLayers.Projection("EPSG:900913")
}
var map = new OpenLayers.Map ("wroc-map", mapOptions);
map.addLayer(mapnikLayer);
...
When I call map.zoomToMaxExtent(), OpenLayers shows what I expect to be whole
world area - not my city. When I display map.getMaxExtent() i get:
max extent: left-bottom=(-20037508.34,-20037508.34)
right-top=(20037508.34,20037508.34)
so maxExtent is evidently not set.
I can do of course:
map.zoomToExtent(new OpenLayers.Bounds(1863611,6614478,1924760,6660340))
but that's not what I want because zoom level is set to 11. I would prefer to
have zl=0 with the view of whole city.
I also tried to use
scales:[220000,150000,100000,50000,20000,10000,5000,2000,1000] instead of
maxExtent and maxResolution, but though I call zoomToExtent... and viewport has
this extent I can see only placeholder tile images with message "...more OSM
data soon".
Is restricting of viewable map area possible?
What am I doing wrong?
Please help.
Shymon
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