gistfile1.m

#import "APMapBoxLayer.h"


@implementation APMapBoxLayer {
	MKMapView *_mapView;
	MBXRasterTileOverlay *_rasterOverlay;
	NSString *_mapId;
	BOOL _usingOfflineMap;
	BOOL _readyToDownload;
	BOOL _didStartDownload;
	NSUInteger _startingZoom;
	MKCoordinateRegion _startingRegion;
}

- (id)initWithLayerData:(NSDictionary *)layerData {
	if ((self = [super initWithLayerData:layerData])) {
		_mapId = layerData[@"mid"];

		_mapView = [[MKMapView alloc] init];
		[self addSubview:_mapView];
		_mapView.frame = self.bounds;
		_mapView.delegate = self;

		MBXOfflineMapDownloader *sharedDownloader = [MBXOfflineMapDownloader sharedOfflineMapDownloader];
		sharedDownloader.delegate = self;

		_rasterOverlay = [[MBXRasterTileOverlay alloc] initWithMapID:_mapId];
		_rasterOverlay.delegate = self;

		[_mapView addOverlay:_rasterOverlay];

		if(sharedDownloader.state == MBXOfflineMapDownloaderStateSuspended) {
			[[MBXOfflineMapDownloader sharedOfflineMapDownloader] resume];
		}
	}

	return self;
}

- (MBXOfflineMapDatabase *)getOfflineDatabaseForMapId:(NSString *)mapId {
	for(MBXOfflineMapDatabase *db in [MBXOfflineMapDownloader sharedOfflineMapDownloader].offlineMapDatabases) {
		if ([db.mapID isEqualToString:mapId]) {
			return db;
		}
	}

	return nil;
}

- (void)downloadMap {
	if (!_readyToDownload || _didStartDownload) return;

	_didStartDownload = YES;

	MBXOfflineMapDownloader *sharedDownloader = [MBXOfflineMapDownloader sharedOfflineMapDownloader];

	if (sharedDownloader.state != MBXOfflineMapDownloaderStateAvailable) return;
	
	if (_usingOfflineMap) return;

	if ([self getOfflineDatabaseForMapId:_mapId]) return;

	[sharedDownloader beginDownloadingMapID:_mapId mapRegion:_startingRegion minimumZ:_startingZoom maximumZ:_startingZoom];
}

- (void)showOfflineMap {
	MBXOfflineMapDatabase *offlineMap = [self getOfflineDatabaseForMapId:_mapId];

	if (offlineMap) {
		_rasterOverlay = [[MBXRasterTileOverlay alloc] initWithOfflineMapDatabase:offlineMap];
		_rasterOverlay.delegate = self;
		_usingOfflineMap = YES;
		_mapView.scrollEnabled = NO;
		_mapView.zoomEnabled = NO;
		_mapView.rotateEnabled = NO;
	}
}

- (void)offlineMapDownloader:(MBXOfflineMapDownloader *)offlineMapDownloader stateChangedTo:(MBXOfflineMapDownloaderState)state {
	[self downloadMap];
}

#ifdef IS_DEBUG
- (void)offlineMapDownloader:(MBXOfflineMapDownloader *)offlineMapDownloader totalFilesExpectedToWrite:(NSUInteger)totalFilesExpectedToWrite {
	LOG(@"MAPBOX to download %lu files", (unsigned long)totalFilesExpectedToWrite);
}

- (void)offlineMapDownloader:(MBXOfflineMapDownloader *)offlineMapDownloader totalFilesWritten:(NSUInteger)totalFilesWritten totalFilesExpectedToWrite:(NSUInteger)totalFilesExpectedToWrite {
	LOG(@"MAPBOX downloaded %lu of %lu files", (unsigned long)totalFilesWritten, (unsigned long)totalFilesExpectedToWrite);
}

- (void)offlineMapDownloader:(MBXOfflineMapDownloader *)offlineMapDownloader didEncounterRecoverableError:(NSError *)error {
	if(error.code == MBXMapKitErrorCodeURLSessionConnectivity) {
		LOG(@"The offline map download was suspended in response to a network connectivity error: %@",error);
	} else if(error.code == MBXMapKitErrorCodeHTTPStatus) {
		// The HTTP status response for one of the urls requested by the offline map came back as something other than 200. This is
		// not necessarily bad, but it probably indicates a problem with the parameters used to begin an offline map download. For
		// example, you might have requested markers for a map that doesn't have any.
		//
		LOG(@"The offline map downloader encountered an HTTP status error: %@",error);
	} else if(error.code == MBXMapKitErrorCodeOfflineMapSqlite) {
		// There was an sqlite error with the offline map. The most likely explanation is that the disk is running out of space.
		//
		LOG(@"The offline map downloader encountered an sqlite error: %@",error);
	}
}
#endif

#pragma mark - MKMapViewDelegate protocol implementation

- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id<MKOverlay>)overlay {
	// This is boilerplate code to connect tile overlay layers with suitable renderers
	//
	if ([overlay isKindOfClass:[MBXRasterTileOverlay class]]) {
		MKTileOverlayRenderer *renderer = [[MKTileOverlayRenderer alloc] initWithTileOverlay:overlay];
		return renderer;
	}
	return nil;
}


- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
	// This is boilerplate code to connect annotations with suitable views
	if ([annotation isKindOfClass:[MBXPointAnnotation class]]) {
		static NSString *MBXSimpleStyleReuseIdentifier = @"MBXSimpleStyleReuseIdentifier";
		MKAnnotationView *view = [mapView dequeueReusableAnnotationViewWithIdentifier:MBXSimpleStyleReuseIdentifier];
		if (!view) {
			view = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:MBXSimpleStyleReuseIdentifier];
		}
		view.image = ((MBXPointAnnotation *)annotation).image;
		view.canShowCallout = YES;
		return view;
	}
	return nil;
}


#pragma mark - MBXRasterTileOverlayDelegate implementation

- (void)tileOverlay:(MBXRasterTileOverlay *)overlay didLoadMetadata:(NSDictionary *)metadata withError:(NSError *)error {
	// This delegate callback is for centering the map once the map metadata has been loaded
	if (error) {
		LOG(@"Failed to load metadata for map ID %@ - (%@)", overlay.mapID, error?error:@"");
		[self showOfflineMap];
	} else {
		[_mapView mbx_setCenterCoordinate:overlay.center zoomLevel:overlay.centerZoom animated:NO];

		_startingZoom = overlay.centerZoom;
		_startingRegion = _mapView.region;
		_readyToDownload = YES;

		[self downloadMap];
	}
}


- (void)tileOverlay:(MBXRasterTileOverlay *)overlay didLoadMarkers:(NSArray *)markers withError:(NSError *)error {
	// This delegate callback is for adding map markers to an MKMapView once all the markers for the tile overlay have loaded
	if (error) {
		LOG(@"Failed to load markers for map ID %@ - (%@)", overlay.mapID, error?error:@"");
	} else {
		[_mapView addAnnotations:markers];
	}
}



@end