o Small changes on the search for a nasty bug

@@ -49,7 +49,6 @@
 @synthesize hasBoundingBox;
 @synthesize enabled;
 @synthesize position;
-@synthesize layer;
 @synthesize quadTreeNode;
 
 + (id)annotationWithMapView:(RMMapView *)aMapView coordinate:(CLLocationCoordinate2D)aCoordinate andTitle:(NSString *)aTitle
@@ -66,7 +65,6 @@
     self.coordinate   = aCoordinate;
     self.title        = aTitle;
     self.userInfo     = nil;
-    self.layer        = nil;
     self.quadTreeNode = nil;
 
     self.annotationType = nil;
@@ -75,17 +73,19 @@
     self.hasBoundingBox = NO;
     self.enabled        = YES;
 
+    layer = nil;
+
     return self;
 }
 
 - (void)dealloc
 {
-    [[self.mapView quadTree] removeAnnotation:self];
     self.title        = nil;
     self.userInfo     = nil;
-    self.mapView      = nil;
     self.layer        = nil;
+    [[self.mapView quadTree] removeAnnotation:self];
     self.quadTreeNode = nil;
+    self.mapView      = nil;
 
     self.annotationType = nil;
     self.annotationIcon = nil;
@@ -116,19 +116,27 @@
 - (void)setPosition:(CGPoint)aPosition
 {
     position = aPosition;
-    if (layer) {
-        layer.position = aPosition;
-    }
+    if (layer) layer.position = aPosition;
+}
+
+- (RMMapLayer *)layer
+{
+    return layer;
 }
 
 - (void)setLayer:(RMMapLayer *)aLayer
 {
     if (layer != aLayer) {
-        [layer removeFromSuperlayer]; [layer release];
-        layer = [aLayer retain];
+        if (layer.superlayer) [layer removeFromSuperlayer];
+        [layer release]; layer = nil;
+    }
+
+    if (aLayer) {
+        layer = aLayer;
+        [layer retain];
         layer.annotation = self;
+        layer.position = self.position;
     }
-    layer.position = self.position;
 }
 
 - (BOOL)isAnnotationWithinBounds:(CGRect)bounds

@@ -56,6 +56,13 @@
     return self;
 }
 
+- (void)dealloc
+{
+    self.annotation = nil;
+    self.userInfo = nil;
+    [super dealloc];
+}
+
 /// return nil for certain animation keys to block core animation
 - (id <CAAction>)actionForKey:(NSString *)key
 {
@@ -65,19 +72,4 @@
         return [super actionForKey:key];
 }
 
-- (void)moveBy:(CGSize)delta
-{
-    self.position = RMTranslateCGPointBy(self.position, delta);
-}
-
-- (void)zoomByFactor:(float)zoomFactor near:(CGPoint)pivot
-{
-    // a empty layer has size=(0,0) which cause divide by 0 if scaled
-    if (self.bounds.size.width == 0.0 || self.bounds.size.height == 0.0)
-        return;
-
-    self.position = RMScaleCGPointAboutPoint(self.position, zoomFactor, pivot);
-    self.bounds = RMScaleCGRectAboutPoint(self.bounds, zoomFactor, pivot);
-}
-
 @end

@@ -1352,7 +1352,7 @@
         boundingBox.size.height += 2*boundingBoxBuffer;
 
         NSArray *annotationsToCorrect = [quadTree annotationsInProjectedRect:boundingBox createClusterAnnotations:self.enableClustering withClusterSize:RMProjectedSizeMake(self.clusterMarkerSize.width * self.metersPerPixel, self.clusterMarkerSize.height * self.metersPerPixel) findGravityCenter:self.positionClusterMarkersAtTheGravityCenter];
-        NSMutableSet *previousVisibleAnnotations = [NSMutableSet setWithSet:visibleAnnotations];
+        NSMutableSet *previousVisibleAnnotations = [[NSMutableSet alloc] initWithSet:visibleAnnotations];
 
         for (RMAnnotation *annotation in annotationsToCorrect)
         {
@@ -1375,10 +1375,12 @@
         {
             if (_delegateHasWillHideLayerForAnnotation) [delegate mapView:self willHideLayerForAnnotation:annotation];
             annotation.layer = nil;
-            [visibleAnnotations removeObject:annotation];
             if (_delegateHasDidHideLayerForAnnotation) [delegate mapView:self didHideLayerForAnnotation:annotation];
+            [visibleAnnotations removeObject:annotation];
         }
 
+        [previousVisibleAnnotations release];
+
 //        RMLog(@"%d annotations on screen, %d total", [overlayView sublayersCount], [annotations count]);
 
     } else

@@ -76,7 +76,6 @@
 
 - (void)dealloc
 {
-    self.userInfo = nil;
     self.label = nil;
     self.textForegroundColor = nil;
     self.textBackgroundColor = nil;

@@ -390,16 +390,9 @@
     }
 }
 
-//- (void)moveBy:(CGSize)delta
-//{
-//    if (enableDragging) {
-//        [super moveBy:delta];
-//    }
-//}
-//
-- (void)setPosition:(CGPoint)value
+- (void)setPosition:(CGPoint)newPosition
 {
-    if (CGPointEqualToPoint(value, super.position) && CGRectEqualToRect(self.bounds, previousBounds)) return;
+    if (CGPointEqualToPoint(newPosition, super.position) && CGRectEqualToRect(self.bounds, previousBounds)) return;
 
     [self recalculateGeometry];
 }

@@ -63,7 +63,7 @@
 
 - (void)dealloc
 {
-    cachedClusterAnnotation.layer = nil; [cachedClusterAnnotation release]; cachedClusterAnnotation = nil;
+    [cachedClusterAnnotation release]; cachedClusterAnnotation = nil;
 
     @synchronized (annotations) {
         for (RMAnnotation *annotation in annotations)
@@ -160,13 +160,13 @@
 - (void)removeAnnotation:(RMAnnotation *)annotation
 {
     if (!annotation.quadTreeNode) return;
+    annotation.quadTreeNode = nil;
 
     @synchronized (annotations) {
         [annotations removeObject:annotation];
     }
 
     [self removeUpwardsAllCachedClusterAnnotations];
-    annotation.quadTreeNode = nil;
 }
 
 - (void)annotationDidChangeBoundingBox:(RMAnnotation *)annotation
@@ -302,7 +302,7 @@
 - (void)removeUpwardsAllCachedClusterAnnotations
 {
     if (parentNode) [parentNode removeUpwardsAllCachedClusterAnnotations];
-    cachedClusterAnnotation.layer = nil; [cachedClusterAnnotation release]; cachedClusterAnnotation = nil;
+    [cachedClusterAnnotation release]; cachedClusterAnnotation = nil;
 }
 
 @end

@@ -13,6 +13,7 @@
 #import "RMMarker.h"
 #import "RMProjection.h"
 #import "RMAnnotation.h"
+#import "RMQuadTree.h"
 
 @implementation MainViewController
 
@@ -29,7 +30,7 @@
 
 - (void)addMarkers
 {
-#define kNumberRows 1
+#define kNumberRows 3
 #define kNumberColumns 9
 #define kSpacing 0.1
 
@@ -73,6 +74,8 @@
 {
     [super viewDidLoad];
     [mapView setDelegate:self];
+    mapView.enableClustering = YES;
+    mapView.positionClusterMarkersAtTheGravityCenter = NO;
 	mapView.tileSource = [[[RMOpenStreetMapSource alloc] init] autorelease];
 
 	center.latitude = 47.5635;
@@ -133,9 +136,18 @@
 
 - (RMMapLayer *)mapView:(RMMapView *)mapView layerForAnnotation:(RMAnnotation *)annotation
 {
-    RMMarker *marker = [[[RMMarker alloc] initWithUIImage:annotation.annotationIcon anchorPoint:annotation.anchorPoint] autorelease];
-    if (annotation.title)
-        [marker changeLabelUsingText:annotation.title];
+    RMMarker *marker = nil;
+    if ([annotation.annotationType isEqualToString:kRMClusterAnnotationTypeName]) {
+        marker = [[[RMMarker alloc] initWithUIImage:[UIImage imageNamed:@"marker-blue.png"] anchorPoint:annotation.anchorPoint] autorelease];
+        if (annotation.title)
+            [marker changeLabelUsingText:annotation.title];
+
+    } else {
+        marker = [[[RMMarker alloc] initWithUIImage:annotation.annotationIcon anchorPoint:annotation.anchorPoint] autorelease];
+        if (annotation.title)
+            [marker changeLabelUsingText:annotation.title];
+    }
+
     return marker;
 }