[ios] Account for center offset when tapping annotation views (#5931)

This adjusts the tap point for the map's single tap gesture
recognizer to use the coordinate to point translated point of the actual
annotation the view represents. This fixes an issue where views that
were offset in the point coordinate system were not selected when
tapped since their associated annotations were actually at the origin
of the offset.

3 files changed, 31 insertions, 0 deletions

diff --git a/platform/ios/ios.xcodeproj/project.pbxproj b/platform/ios/ios.xcodeproj/project.pbxproj
index d6a741f33e..1bdc3e7a76 100644
--- a/platform/ios/ios.xcodeproj/project.pbxproj
+++ b/platform/ios/ios.xcodeproj/project.pbxproj
@@ -19,6 +19,7 @@
 		4018B1C91CDC288A00F666AF /* MGLAnnotationView_Private.h in Headers */ = {isa = PBXBuildFile; fileRef = 4018B1C31CDC277F00F666AF /* MGLAnnotationView_Private.h */; };
 		4018B1CA1CDC288E00F666AF /* MGLAnnotationView.h in Headers */ = {isa = PBXBuildFile; fileRef = 4018B1C51CDC277F00F666AF /* MGLAnnotationView.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		4018B1CB1CDC288E00F666AF /* MGLAnnotationView.h in Headers */ = {isa = PBXBuildFile; fileRef = 4018B1C51CDC277F00F666AF /* MGLAnnotationView.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		404326891D5B9B27007111BD /* MGLAnnotationContainerView_Private.h in Headers */ = {isa = PBXBuildFile; fileRef = 404326881D5B9B1A007111BD /* MGLAnnotationContainerView_Private.h */; };
 		40EDA1C01CFE0E0200D9EA68 /* MGLAnnotationContainerView.h in Headers */ = {isa = PBXBuildFile; fileRef = 40EDA1BD1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.h */; };
 		40EDA1C11CFE0E0500D9EA68 /* MGLAnnotationContainerView.m in Sources */ = {isa = PBXBuildFile; fileRef = 40EDA1BE1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.m */; };
 		40EDA1C21CFE0E0500D9EA68 /* MGLAnnotationContainerView.m in Sources */ = {isa = PBXBuildFile; fileRef = 40EDA1BE1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.m */; };
@@ -341,6 +342,7 @@
 		4018B1C41CDC277F00F666AF /* MGLAnnotationView.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = MGLAnnotationView.mm; sourceTree = "<group>"; };
 		4018B1C51CDC277F00F666AF /* MGLAnnotationView.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLAnnotationView.h; sourceTree = "<group>"; };
 		402E9DE01CD2C76200FD4519 /* Mapbox.playground */ = {isa = PBXFileReference; lastKnownFileType = file.playground; path = Mapbox.playground; sourceTree = "<group>"; };
+		404326881D5B9B1A007111BD /* MGLAnnotationContainerView_Private.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MGLAnnotationContainerView_Private.h; sourceTree = "<group>"; };
 		40EDA1BD1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLAnnotationContainerView.h; sourceTree = "<group>"; };
 		40EDA1BE1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MGLAnnotationContainerView.m; sourceTree = "<group>"; };
 		40FDA7691CCAAA6800442548 /* MBXAnnotationView.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MBXAnnotationView.h; sourceTree = "<group>"; };
@@ -929,6 +931,7 @@
 			isa = PBXGroup;
 			children = (
 				40EDA1BD1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.h */,
+				404326881D5B9B1A007111BD /* MGLAnnotationContainerView_Private.h */,
 				40EDA1BE1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.m */,
 				4018B1C51CDC277F00F666AF /* MGLAnnotationView.h */,
 				4018B1C31CDC277F00F666AF /* MGLAnnotationView_Private.h */,
@@ -977,6 +980,7 @@
 				DA88482C1CBAFA6200AB86E3 /* NSBundle+MGLAdditions.h in Headers */,
 				DA88488E1CBB047F00AB86E3 /* reachability.h in Headers */,
 				DA8848231CBAFA6200AB86E3 /* MGLOfflineStorage_Private.h in Headers */,
+				404326891D5B9B27007111BD /* MGLAnnotationContainerView_Private.h in Headers */,
 				DA88483B1CBAFB8500AB86E3 /* MGLCalloutView.h in Headers */,
 				DA8848531CBAFB9800AB86E3 /* MGLCompactCalloutView.h in Headers */,
 				DA8847FB1CBAFA5100AB86E3 /* MGLShape.h in Headers */,
diff --git a/platform/ios/src/MGLAnnotationContainerView_Private.h b/platform/ios/src/MGLAnnotationContainerView_Private.h
new file mode 100644
index 0000000000..007b03550b
--- /dev/null
+++ b/platform/ios/src/MGLAnnotationContainerView_Private.h
@@ -0,0 +1,14 @@
+#import "MGLAnnotationContainerView.h"
+#import "MGLAnnotationView.h"
+
+@class MGLAnnotationView;
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface MGLAnnotationContainerView (Private)
+
+@property (nonatomic) NS_MUTABLE_ARRAY_OF(MGLAnnotationView *) *annotationViews;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index 9ef042ad3e..09eb2319a2 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -42,6 +42,7 @@
 #import "MGLMapboxEvents.h"
 #import "MGLCompactCalloutView.h"
 #import "MGLAnnotationContainerView.h"
+#import "MGLAnnotationContainerView_Private.h"
 
 #import <algorithm>
 #import <cstdlib>
@@ -1407,6 +1408,18 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
     }
 
     CGPoint tapPoint = [singleTap locationInView:self];
+   
+    // Handle the case of an offset annotation view by converting the tap point to be the geo location
+    // of the annotation itself that the view represents
+    for (MGLAnnotationView *view in self.annotationContainerView.annotationViews)
+    {
+        if (view.centerOffset.dx != 0 || view.centerOffset.dy != 0) {
+            if (CGRectContainsPoint(view.frame, tapPoint)) {
+                CGPoint annotationPoint = [self convertCoordinate:view.annotation.coordinate toPointToView:self];
+                tapPoint = annotationPoint;
+            }
+        }
+    }
     
     MGLAnnotationTag hitAnnotationTag = [self annotationTagAtPoint:tapPoint persistingResults:YES];
     if (hitAnnotationTag != MGLAnnotationTagNotFound)