Reposition map to fit callouts

include/mbgl/ios/MGLMapView.h

@@ -41,6 +41,14 @@ IB_DESIGNABLE
 *   @return An initialized map view. */
 - (instancetype)initWithFrame:(CGRect)frame styleURL:(nullable NSURL *)styleURL;
 
+/** Edge insets for positioning callouts.
+ *  
+ *  If your `MGLMapView` is obstructed by transparent navbars or toolbars you may want to set the top and bottom insets to the
+ *  top and bottom layout guides from your view controller.
+ *
+ *  The default value of this property is `UIEdgeInsetsZero`. */
+@property(nonatomic) UIEdgeInsets calloutInsets;
+
 #pragma mark - Accessing Map Properties
 
 /** @name Accessing Map Properties */

platform/ios/MGLMapView.mm

@@ -106,6 +106,7 @@ @interface MGLMapView () <UIGestureRecognizerDelegate,
 @property (nonatomic) CGFloat quickZoomStart;
 @property (nonatomic, getter=isDormant) BOOL dormant;
 @property (nonatomic, readonly, getter=isRotationAllowed) BOOL rotationAllowed;
+@property (nonatomic, strong) SMCalloutView *repositioningCalloutView;
 
 @end
 
@@ -268,6 +269,8 @@ - (void)commonInit
 
     _annotationImages = [NSMutableDictionary dictionary];
 
+    _calloutInsets = UIEdgeInsetsZero;
+
     // setup logo bug
     //
     UIImage *logo = [[MGLMapView resourceImageNamed:@"mapbox.png"] imageWithAlignmentRectInsets:UIEdgeInsetsMake(1.5, 4, 3.5, 2)];
@@ -1976,6 +1979,11 @@ CLLocationCoordinate2D MGLLocationCoordinate2DFromLatLng(mbgl::LatLng latLng)
     return bounds;
 }
 
+- (CGRect)viewportRectWithInsets:(UIEdgeInsets)insets
+{
+    return CGRectMake(insets.left, insets.top, self.bounds.size.width - (insets.left + insets.right), self.bounds.size.height - (insets.top + insets.bottom));
+}
+
 #pragma mark - Styling -
 
 - (NS_ARRAY_OF(NSURL *) *)bundledStyleURLs
@@ -2431,10 +2439,14 @@ - (void)selectAnnotation:(id <MGLAnnotation>)annotation animated:(BOOL)animated
         // set annotation delegate to handle taps on the callout view
         self.selectedAnnotationCalloutView.delegate = self;
 
+        // create constraining view based on user insets
+        CGRect viewportRect = [self viewportRectWithInsets:self.calloutInsets];
+        UIView *constrainingView = [UIView.alloc initWithFrame:viewportRect];
+
         // present popup
         [self.selectedAnnotationCalloutView presentCalloutFromRect:calloutBounds
                                                             inView:self.glView
-                                                 constrainedToView:self.glView
+                                                 constrainedToView:constrainingView
                                                           animated:animated];
     }
 
@@ -2445,6 +2457,16 @@ - (void)selectAnnotation:(id <MGLAnnotation>)annotation animated:(BOOL)animated
     }
 }
 
+- (NSTimeInterval)calloutView:(SMCalloutView *)calloutView delayForRepositionWithSize:(CGSize)offset
+{
+    self.repositioningCalloutView = calloutView;
+
+    _mbglMap->moveBy(offset.width, offset.height, secondsAsDuration(MGLAnimationDuration));
+    calloutView.frame = CGRectOffset(calloutView.frame, offset.width, offset.height);
+
+    return MGLAnimationDuration;
+}
+
 - (SMCalloutView *)calloutViewForAnnotation:(id <MGLAnnotation>)annotation
 {
     SMCalloutView *calloutView = [SMCalloutView platformCalloutView];
@@ -2899,7 +2921,11 @@ - (void)notifyMapChange:(mbgl::MapChange)change
         case mbgl::MapChangeRegionWillChange:
         case mbgl::MapChangeRegionWillChangeAnimated:
         {
-            [self deselectAnnotation:self.selectedAnnotation animated:NO];
+            // Don't deselect the annotation if we are repositioning to fit a callout view.
+            if (!self.repositioningCalloutView) {
+                [self deselectAnnotation:self.selectedAnnotation animated:NO];
+            }
+            self.repositioningCalloutView = nil;
 
             if ( ! [self isSuppressingChangeDelimiters] && [self.delegate respondsToSelector:@selector(mapView:regionWillChangeAnimated:)])
             {