Is CGPoint in MKPolygonView? - ios

Question

I'm trying to figure out a way to detect which MKOverlayView (actually MKPolygonView) was tapped and then change its color.
I got it running with this code:
- (void)mapTapped:(UITapGestureRecognizer *)recognizer {
MKMapView *mapView = (MKMapView *)recognizer.view;
MKPolygonView *tappedOverlay = nil;
for (id<MKOverlay> overlay in mapView.overlays)
{
MKPolygonView *view = (MKPolygonView *)[mapView viewForOverlay:overlay];
if (view){
// Get view frame rect in the mapView's coordinate system
CGRect viewFrameInMapView = [view.superview convertRect:view.frame toView:mapView];
// Get touch point in the mapView's coordinate system
CGPoint point = [recognizer locationInView:mapView];
// Check if the touch is within the view bounds
if (CGRectContainsPoint(viewFrameInMapView, point))
{
tappedOverlay = view;
break;
}
}
}
if([[tappedOverlay fillColor] isEqual:[[UIColor cyanColor] colorWithAlphaComponent:0.2]]){
[listOverlays addObject:tappedOverlay];
tappedOverlay.fillColor = [[UIColor redColor] colorWithAlphaComponent:0.2];
}
else{
[listOverlays removeObject:tappedOverlay];
tappedOverlay.fillColor = [[UIColor cyanColor] colorWithAlphaComponent:0.2];
}
//tappedOverlay.strokeColor = [[UIColor blueColor] colorWithAlphaComponent:0.7];
}
Which works but sometimes, depending where I tap it gets wrong which MKPolygonView was tapped. I suppose because CGRectContainsPoint doesnt calculate properly the area, since it's not a rectangle it's a Polygon.
What other methods there are to do this? I tried CGPathContainsPoint but I get worse results.

Answer 1

Thanks to #Ana Karenina, that pointed out the right way, this is how you have to convert the gesture so that the method CGPathContainsPoint' works right.
- (void)mapTapped:(UITapGestureRecognizer *)recognizer{
MKMapView *mapView = (MKMapView *)recognizer.view;
MKPolygonView *tappedOverlay = nil;
int i = 0;
for (id<MKOverlay> overlay in mapView.overlays)
{
MKPolygonView *view = (MKPolygonView *)[mapView viewForOverlay:overlay];
if (view){
CGPoint touchPoint = [recognizer locationInView:mapView];
CLLocationCoordinate2D touchMapCoordinate =
[mapView convertPoint:touchPoint toCoordinateFromView:mapView];
MKMapPoint mapPoint = MKMapPointForCoordinate(touchMapCoordinate);
CGPoint polygonViewPoint = [view pointForMapPoint:mapPoint];
if(CGPathContainsPoint(view.path, NULL, polygonViewPoint, NO)){
tappedOverlay = view;
tappedOverlay.tag = i;
break;
}
}
i++;
}
if([[tappedOverlay fillColor] isEqual:[[UIColor cyanColor] colorWithAlphaComponent:0.2]]){
[listOverlays addObject:tappedOverlay];
tappedOverlay.fillColor = [[UIColor redColor] colorWithAlphaComponent:0.2];
}
else{
[listOverlays removeObject:tappedOverlay];
tappedOverlay.fillColor = [[UIColor cyanColor] colorWithAlphaComponent:0.2];
}
//tappedOverlay.strokeColor = [[UIColor blueColor] colorWithAlphaComponent:0.7];
}