Hello Arnd, Thanks for the reference.
Both scales[] and resolutions[] seem to be ideal for supporting maps of a known/fixed area, say a particular country. However, my problem is that I was to set the minimum zoom at run time and don't know what to load into those arrays. Any suggestions? I've still got a worldwide TMS layer, but just want to stop the end user wandering around. Extents stop the user panning, but zoom is still a problem. I see that a minZoom is supported to pass thru to commercial layers like Google, but this is not supported generally (a worthy enhancement IMHO). In an ideal world (excuse the pun), I'd like to zoom to a max extent, query the zoom level, and then set that as the min zoom for the map. I'd then have a nice "tight" map extent for the user. Regards, Warren -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: 20 February 2009 22:42 To: Warren Vick Cc: [email protected] Subject: AW: [OpenLayers-Users] Min Zoom Level Hi, Have a look at http://n2.nabble.com/projections-resolution-extents-td1826696.html. Instead of scales[] you can also use resolutions[]. Arnd Wippermann -----Ursprüngliche Nachricht----- Von: [email protected] [mailto:[email protected]] Im Auftrag von Warren Vick Gesendet: Donnerstag, 19. Februar 2009 19:35 An: [email protected] Betreff: Re: [OpenLayers-Users] Min Zoom Level I'm still a bit stuck on implementing a minimum zoom level and would appreciate any more feedback. My problem is that my starting point is a bound for any country of the world. So, the number of zoom levels for a large country will be different from a small one. So, even if the scales[] property is the way to go (and I haven't got it working yet), I don't know what to load into that array. Regards, Warren Vick -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Warren Vick Sent: 12 February 2009 13:46 To: Matthias Woltering Cc: [email protected] Subject: Re: [OpenLayers-Users] Min Zoom Level Ah, I see. So, the final part of my question is... what are the scale values for the standard zoom levels in OL? Is it the same as Min/MaxScaleDenominator when rendering TMS tiles? Regards, Warren -----Original Message----- From: Matthias Woltering [mailto:[email protected]] Sent: 12 February 2009 13:29 To: Warren Vick Cc: [email protected] Subject: Re: [OpenLayers-Users] Min Zoom Level Hi Warren, if you add the PanZoomBar map.addControl(new OpenLayers.Control.PanZoomBar()); you will have as much zoomlevels as you have defined in the scales-section. In the previous example there will be 7 zoom-levels. Regards, Matthias Warren Vick schrieb: > Hi Matthias, > > Thanks for the prompt feedback. How would changing the scale of each > zoom level limit the number of levels available to the user? In my case, > I have 11 zoom levels but want to start at level 6. So, my zoom control > would only represents the levels between 6 and 11. > > Regards, > Warren > > -----Original Message----- > From: Matthias Woltering [mailto:[email protected]] > Sent: 12 February 2009 13:00 > To: Warren Vick > Cc: [email protected] > Subject: Re: [OpenLayers-Users] Min Zoom Level > > Hi Warren, > > you can set set the scales manually like this: > > var options = { > maxExtent: new OpenLayers.Bounds(1430000,4400000,1760000,4660000) > ,maxResolution: "auto" > ,scales: [1000000,500000,250000,100000,50000,25000,10000] > ,units: 'm' > ,projection: 'EPSG:31466' > ,controls: [] > //,zoom: 1 > //,numZoomLevels: 8 > }; > map = new OpenLayers.Map('map', options); > > If you don't want to set scales use numZoomLevels. > > Regards, > Matthias > > > Warren Vick schrieb: >> How can I set a minimum zoom level for a map? Focussing on a single >> country, I know how to limit the extent but can't figure out how to > stop >> someone zooming out and seeing TMS tiles that have not been rendered. >> >> Regards, >> Warren >> >> _______________________________________________ >> Users mailing list >> [email protected] >> http://openlayers.org/mailman/listinfo/users > > > _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
