[ios] Don't use negative content insets

platform/ios/CHANGELOG.md

@@ -7,6 +7,7 @@ Mapbox welcomes participation and contributions from everyone.  If you’d like
 - If you’ve previously installed the SDK as a static framework, the installation workflow has changed to address issues when submitting your application to the App Store or installing it on a device. Upon upgrading to this version of the SDK, you’ll need to add Mapbox.bundle to the Copy Bundle Resources build phase and remove Mapbox.framework from the Embed Frameworks build phase. ([#4455](https://github.com/mapbox/mapbox-gl-native/pull/4455))
 - Offline packs can now be downloaded to allow users to view specific regions of the map offline. A new MGLOfflineStorage class provides APIs for managing MGLOfflinePacks. ([#4221](https://github.com/mapbox/mapbox-gl-native/pull/4221))
 - Tiles and other resources are cached in the same file that holds offline resources. The combined cache file is located in a subdirectory of the user’s Application Support directory, which means iOS will not delete the file when disk space runs low. ([#4377](https://github.com/mapbox/mapbox-gl-native/pull/4377))
+- Fixed an issue where the map view’s center would always be calculated as if the view occupied the entire screen. ([#4504](https://github.com/mapbox/mapbox-gl-native/issues/4504))
 - The user dot no longer disappears after panning the map across the antimeridian at low zoom levels. ([#4275](https://github.com/mapbox/mapbox-gl-native/pull/4275))
 - The map no longer recoils when panning quickly at low zoom levels. ([#4214](https://github.com/mapbox/mapbox-gl-native/pull/4214))
 - Fixed an issue causing the map to pan the wrong way when the user pinches unevenly. ([#4427](https://github.com/mapbox/mapbox-gl-native/pull/4427))

platform/ios/src/MGLMapView.mm

@@ -814,6 +814,11 @@ - (void)adjustContentInset
                                       - viewController.bottomLayoutGuide.length);
     contentInset.bottom = (CGRectGetMaxY(self.bounds)
                            - [self convertPoint:bottomPoint fromView:viewController.view].y);
+
+    // Negative insets are invalid, replace with 0.
+    contentInset.top = fmaxf(contentInset.top, 0);
+    contentInset.bottom = fmaxf(contentInset.bottom, 0);
+
     self.contentInset = contentInset;
 }
 
@@ -2964,9 +2969,9 @@ - (void)deselectAnnotation:(id <MGLAnnotation>)annotation animated:(BOOL)animate
 
 - (void)showAnnotations:(NS_ARRAY_OF(id <MGLAnnotation>) *)annotations animated:(BOOL)animated
 {
-    CGFloat defaultPadding = 100;
-    CGFloat yPadding = (self.frame.size.height / 2 <= defaultPadding) ? (self.frame.size.height / 5) : defaultPadding;
-    CGFloat xPadding = (self.frame.size.width / 2 <= defaultPadding) ? (self.frame.size.width / 5) : defaultPadding;
+    CGFloat maximumPadding = 100;
+    CGFloat yPadding = (self.frame.size.height / 5 <= maximumPadding) ? (self.frame.size.height / 5) : maximumPadding;
+    CGFloat xPadding = (self.frame.size.width / 5 <= maximumPadding) ? (self.frame.size.width / 5) : maximumPadding;
 
     UIEdgeInsets edgeInsets = UIEdgeInsetsMake(yPadding, xPadding, yPadding, xPadding);
 

platform/ios/test/MGLTViewController.h

@@ -3,6 +3,7 @@
 @interface MGLTViewController : UIViewController
 
 - (void)insetMapView;
+- (void)tinyMapView;
 - (void)resetMapView;
 
 @end

platform/ios/test/MGLTViewController.m

@@ -21,6 +21,11 @@ - (void)insetMapView
     _mapView.frame = CGRectInset(_mapView.frame, 50, 50);
 }
 
+- (void)tinyMapView
+{
+    _mapView.frame = CGRectMake(20, self.topLayoutGuide.length, self.view.frame.size.width / 2, self.view.frame.size.height / 2);
+}
+
 - (void)resetMapView
 {
     _mapView.frame = self.view.bounds;

platform/ios/test/MapViewTests.m

@@ -424,6 +424,29 @@ - (void)testInsetMapView {
                   @"compass should lie inside shrunken map view");
 }
 
+- (void)testContentInsetsWithTinyMapView {
+    [tester.viewController tinyMapView];
+    [self keyValueObservingExpectationForObject:tester.mapView keyPath:@"contentInset" handler:^BOOL(id observedObject, NSDictionary *change) {
+        XCTAssertEqual(tester.mapView.contentInset.top,
+                       0,
+                       @"map should not have top content inset");
+        XCTAssertEqual(tester.mapView.contentInset.bottom,
+                       0,
+                       @"map should not have bottom content inset");
+        return YES;
+    }];
+    [self waitForExpectationsWithTimeout:2.0 handler:nil];
+
+    tester.mapView.frame = CGRectMake(0, 0, tester.mapView.frame.size.width, tester.mapView.frame.size.height);
+    [self keyValueObservingExpectationForObject:tester.mapView keyPath:@"contentInset" handler:^BOOL(id observedObject, NSDictionary *change) {
+        XCTAssertEqual(tester.mapView.contentInset.top,
+                       tester.viewController.topLayoutGuide.length,
+                       @"map should have top content inset equal to the top layout guide");
+        return YES;
+    }];
+    [self waitForExpectationsWithTimeout:2.0 handler:nil];
+}
+
 - (void)testDelegateRegionWillChange {
     __block NSUInteger unanimatedCount;
     __block NSUInteger animatedCount;