Barry, I have starred that issue as you recommend.
What I was saying about the zoom slider has to do with my experience with the API. So my application saves a marker point the user saves. They can save that point to their profile and then go back to it at a later date. In the initial testing phases I would simply save the lat/lon and when I went to display it I set the zoom level to 19 or 20. To be honest this was due to the fact I didn't know there was an issue with lack of coverage in some areas. Fortunately (or unfortunately in my case) during the testing phase it happened that all of the areas I was using had high-resolution (i.e. 19 or 20 zoom level) imagery available. When we opened it up for testing outside of the development group we found the lovely "sorry" there is not imagery available at this location please try zooming out message. I found it hugely frustrating that if I had set the zoom to 20 ... and zoom out to say 16 that it would NOT let me zoom back in to 20 again and get the error message. So, my assumption was that Google "knew" there was no imagery available at that zoom level and didn't allow me to get there. If you try doing a search at or around Savannah, Georgia and save a lat/lon and set the zoom to 20 you will have this exact issue. I have been able to reproduce in various other areas as well. So, that said, I am curious if anyone has any knowledge of potentially creating a hack/workaround that would watch the tile layer (or whatever issues the no imagery available at this zoom level message) catch it and find the highest zoom level with available imagery backwards rather than frustrate my user with an "imagery unavailable at this zoom level" message. Does that make sense? Desperately looking for a solution. Regards, Chris On Sat, Nov 1, 2008 at 8:26 PM, Barry Hunter <[EMAIL PROTECTED]>wrote: > > You should star this issue: > http://code.google.com/p/gmaps-api-issues/issues/detail?id=55 > (and not just add an inane comment - they are ignored - and do nothing > but frustrate) > > > Otherwise I dont know quite what you mean about the zoom slider. The > API doesn't know what zoom levels are available. All it does is try > setting a zoom level, and if loading the tiles fail, then it puts that > message. I suppose its possible it uses a failure and then sets that > as a max zoom level, but personally never seen that - Just tried it > now and it doesn't appear to do that. > > Knowing in advance what levels are available would be difficult, and > would really require a request to check if anything available - which > would slow zooming, and require the server infrastructure to support > it. I doubt a database is maintained about zoomlevels, its simply if a > tile is available. (although I suppose a webservice could be made that > just checks if a given tile is available - very quickly - the API > could then check a single central tile*) > > * I don't believe it can use the current system to reliably detect no > imagery, as the tile could fail loading for different reasons, and a > authoritative no from a webservice would at least be deterministic. > Actually using the tile server for this would be wasteful as you > couldn't use the image returned so it would only slow matters and > waste bandwidth. > > > > > > On Sat, Nov 1, 2008 at 11:11 PM, cthornbe <[EMAIL PROTECTED]> > wrote: > > > > OK, I know this has been discussed a couple of times in different > > places on the group but I'm going to ask this question again to see if > > there are any hacks out there and might spark someone's creativity :-) > > > > Here is my frustration ... > > > > I have a custom application that uses the Google Maps API to identify > > locations. Once I identify a location I really need to know what the > > maximum available zoom level for satellite imagery is at that specific > > lat/lon point. > > > > From everything I have read online and on the newsgroup here that > > there is absolutely no way to determine the maximum zoom level. My > > question, however, is that why if you set a zoom level when you find > > the location and it is something less than the maximum available zoom > > at that location will it only allow you access to available zoom > > levels? > > > > I am going to take it because the Developers know what the maximum > > zoom is and just don't give us access to that information. So, where > > my thought process comes in is would it be possible through some type > > of JavaScript to go through the process of setting a zoom level (say > > 16) and them programatically have my software attempt to zoom using > > the MapControl to determine that max zoom level? > > > > Hopefully this makes sense ... I know it's a potential hack, but I > > believe is something that should definitely be made available in a > > future release of the API. Hopefully the next one ;-) > > > > > > > > > > > -- > Barry > > - www.nearby.org.uk - www.geograph.org.uk - > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
