[ios] Optional positioning and stickiness for callout view

platform/ios/app/MBXCustomCalloutView.m

@@ -17,6 +17,8 @@ @implementation MBXCustomCalloutView {
 }
 
 @synthesize representedObject = _representedObject;
+@synthesize automaticPositioning = _automaticPositioning;
+@synthesize staysOpen = _staysOpen;
 @synthesize leftAccessoryView = _leftAccessoryView;
 @synthesize rightAccessoryView = _rightAccessoryView;
 @synthesize delegate = _delegate;
@@ -66,6 +68,11 @@ - (void)presentCalloutFromRect:(CGRect)rect inView:(UIView *)view constrainedToV
     }
 }
 
+- (void)setCenter:(CGPoint)center {
+    center.y = center.y - CGRectGetMidY(self.bounds);
+    [super setCenter:center];
+}
+
 - (void)dismissCalloutAnimated:(BOOL)animated
 {
     if (self.superview)

platform/ios/app/MBXViewController.m

@@ -89,6 +89,8 @@ @implementation MBXDroppedPinAnnotation
 @end
 
 @interface MBXCustomCalloutAnnotation : MGLPointAnnotation
+@property (nonatomic, assign) BOOL automaticPositioning;
+@property (nonatomic, assign) BOOL staysOpen;
 @end
 
 @implementation MBXCustomCalloutAnnotation
@@ -699,12 +701,28 @@ - (void)addAnnotationWithCustomCallout
 {
     [self.mapView removeAnnotations:self.mapView.annotations];
 
-    MBXCustomCalloutAnnotation *annotation = [[MBXCustomCalloutAnnotation alloc] init];
-    annotation.coordinate = CLLocationCoordinate2DMake(48.8533940, 2.3775439);
-    annotation.title = @"Custom Callout";
-
-    [self.mapView addAnnotation:annotation];
-    [self.mapView showAnnotations:@[annotation] animated:YES];
+    MBXCustomCalloutAnnotation *firstAnnotation = [[MBXCustomCalloutAnnotation alloc] init];
+    firstAnnotation.coordinate = CLLocationCoordinate2DMake(48.8533940, 2.3775439);
+    firstAnnotation.title = @"Open w/ auto positioning";
+    firstAnnotation.automaticPositioning = YES;
+    firstAnnotation.staysOpen = YES;
+
+    MBXCustomCalloutAnnotation *secondAnnotation = [[MBXCustomCalloutAnnotation alloc] init];
+    secondAnnotation.coordinate = CLLocationCoordinate2DMake(48.8543940, 2.3775439);
+    secondAnnotation.title = @"Open w/o automatic positioning";
+    secondAnnotation.automaticPositioning = NO;
+    secondAnnotation.staysOpen = YES;
+
+    MBXCustomCalloutAnnotation *thirdAnnotation = [[MBXCustomCalloutAnnotation alloc] init];
+    thirdAnnotation.coordinate = CLLocationCoordinate2DMake(48.8553940, 2.3775439);
+    thirdAnnotation.title = @"Closes";
+    thirdAnnotation.automaticPositioning = NO;
+    thirdAnnotation.staysOpen = NO;
+
+    NSArray *annotations = @[firstAnnotation, secondAnnotation, thirdAnnotation];
+    [self.mapView addAnnotations:annotations];
+
+    [self.mapView showAnnotations:annotations animated:YES];
 }
 
 - (void)styleWaterLayer
@@ -1582,8 +1600,12 @@ - (void)mapView:(__unused MGLMapView *)mapView didChangeUserTrackingMode:(MGLUse
     if ([annotation respondsToSelector:@selector(title)]
         && [annotation isKindOfClass:[MBXCustomCalloutAnnotation class]])
     {
+        MBXCustomCalloutAnnotation *customAnnotation = (MBXCustomCalloutAnnotation *)annotation;
+
         MBXCustomCalloutView *calloutView = [[MBXCustomCalloutView alloc] init];
         calloutView.representedObject = annotation;
+        calloutView.automaticPositioning = customAnnotation.automaticPositioning;
+        calloutView.staysOpen = customAnnotation.staysOpen;
         return calloutView;
     }
     return nil;

platform/ios/src/MGLCalloutView.h

@@ -35,6 +35,18 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @property (nonatomic, weak) id<MGLCalloutViewDelegate> delegate;
 
+/**
+ A Boolean value indicating whether the callout view should be positioned automatically.
+ The exact position can be adjusted by overriding -[UIView setCenter:]
+ */
+@property (nonatomic, assign) BOOL automaticPositioning;
+
+/**
+ A Boolean value indicating whether the callout view should be dismissed or not
+ when the map view changes viewport.
+ */
+@property (nonatomic, assign) BOOL staysOpen;
+
 /**
  Presents a callout view by adding it to `view` and pointing at the given rect
  of `view`’s bounds. Constrains the callout to the bounds of the given view.

platform/ios/src/MGLCompactCalloutView.m

@@ -8,6 +8,16 @@ @implementation MGLCompactCalloutView
 }
 
 @synthesize representedObject = _representedObject;
+@synthesize automaticPositioning = _automaticPositioning;
+@synthesize staysOpen = _staysOpen;
+
+- (instancetype)init {
+    if (self = [super init]) {
+        _automaticPositioning = YES;
+        _staysOpen = YES;
+    }
+    return self;
+}
 
 + (instancetype)platformCalloutView
 {

platform/ios/src/MGLMapView.mm

@@ -4558,21 +4558,30 @@ - (void)notifyMapChange:(mbgl::MapChange)change
                 || self.userTrackingMode == MGLUserTrackingModeNone
                 || self.userTrackingState != MGLUserTrackingStateChanged)
             {
-                // Deselect annotation if it lies outside the viewport
-                if (self.selectedAnnotation) {
-                    MGLAnnotationTag tag = [self annotationTagForAnnotation:self.selectedAnnotation];
-                    MGLAnnotationContext &annotationContext = _annotationContextsByAnnotationTag.at(tag);
-                    MGLAnnotationView *annotationView = annotationContext.annotationView;
-
-                    CGRect rect = [self positioningRectForCalloutForAnnotationWithTag:tag];
-
-                    if (annotationView)
-                    {
-                        rect = annotationView.frame;
-                    }
-
-                    if ( ! CGRectIntersectsRect(rect, self.frame)) {
-                        [self deselectAnnotation:self.selectedAnnotation animated:NO];
+                BOOL calloutViewStaysOpen = (self.calloutViewForSelectedAnnotation && self.calloutViewForSelectedAnnotation.staysOpen);
+
+                if ( ! calloutViewStaysOpen)
+                {
+                    [self deselectAnnotation:self.selectedAnnotation animated:NO];
+                }
+                else
+                {
+                    // Deselect annotation if it lies outside the viewport
+                    if (self.selectedAnnotation) {
+                        MGLAnnotationTag tag = [self annotationTagForAnnotation:self.selectedAnnotation];
+                        MGLAnnotationContext &annotationContext = _annotationContextsByAnnotationTag.at(tag);
+                        MGLAnnotationView *annotationView = annotationContext.annotationView;
+
+                        CGRect rect = [self positioningRectForCalloutForAnnotationWithTag:tag];
+
+                        if (annotationView)
+                        {
+                            rect = annotationView.frame;
+                        }
+
+                        if ( ! CGRectIntersectsRect(rect, self.frame)) {
+                            [self deselectAnnotation:self.selectedAnnotation animated:NO];
+                        }
                     }
                 }
             }
@@ -4817,7 +4826,7 @@ - (void)updateCalloutView
     UIView <MGLCalloutView> *calloutView = self.calloutViewForSelectedAnnotation;
     id <MGLAnnotation> annotation = calloutView.representedObject;
 
-    if (calloutView && annotation)
+    if (calloutView && annotation && calloutView.automaticPositioning)
     {
         MGLAnnotationTag tag = [self annotationTagForAnnotation:annotation];
         MGLAnnotationContext &annotationContext = _annotationContextsByAnnotationTag.at(tag);