WMS with Google Maps on iOS

Screen Shot 2014-04-21 at 00.49.02Sample for using WMS sources in Google Maps SDK for iOS. available on github here: https://github.com/Sumbera/WMS_iOS_GoogleMapSDK
Provide your API key in the WMSController.h

  • Google Maps for iOS used : 1.7.2 (April 2014)
  • used XCode 5.1.1 (April 2014)
  • iPad Air, iOS 7.1 (should run in iOS6.0 too)

 

There are two ways of overlaying WMS in the Google Maps for iOS SDK:

“Method B”: use GMSTileURLConstructor

   // -- method B. WMS tile layer with GMSTileURLConstructor
      GMSTileURLConstructor urls = 
         ^(NSUInteger x, NSUInteger y, NSUInteger z) {
           BBox bbox = bboxFromXYZ(x,y,z);
           NSString *urlKN = 
             [NSString stringWithFormat:@"Your WMS url&BBOX=%f,%f,%f,%f",
                                           bbox.left,
                                           bbox.bottom,
                                           bbox.right,
                                           bbox.top];

          return [NSURL URLWithString:urlKN];
      };

“Method A”: use custom TileLayer derived from GMSTileLayer

  1. your derived class from GMSTileLayer (here WMSTileLayer.h) will receive tile request
     -(void)requestTileForX:(NSUInteger)x 
                                     y:(NSUInteger)y
                                  zoom:(NSUInteger)z 
                              receiver:(id<GMSTileReceiver>)receiver
    
  2. WMSTileLayer first checks for cached tile and if found calls :
      [self drawTileAtX:x y:y zoom:z Url:urlStr Receiver:receiver] ;
    
  3. if tile is not cached we download it, save it to the file system (using MD5 hash) and call to draw it
      [data  writeToFile: filePath  atomically:YES];
      [self drawTileAtX:x y: y zoom: z Url:urlStr Receiver:receiver] ;
    
  4. drawTileAtX is very simple:
      -(void) drawTileAtX: (NSUInteger) x 
                                   y:(NSUInteger) y
                                zoom:(NSUInteger)zoom
                                 Url:(NSString*) url
                            Receiver: (id<GMSTileReceiver>) receiver {
           UIImage             *image   = TileLoad(url,NO); 
           [receiver receiveTileWithX:x y:y zoom:zoom image:image]; 
      }
    

}

both ways are used in this sample.

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