ios-setLatLngBounds (#1455)

Co-authored-by: Julian Bissekkou <julian.bissekkou@tapped.dev>

platform/ios/CHANGELOG.md

@@ -3,7 +3,7 @@
 MapLibre welcomes participation and contributions from everyone. Please read [`Contributing Guide`](https://github.com/maplibre/maplibre-native/blob/master/CONTRIBUTING.md) to get started.
 
 ## main
-
+* Add `MLNMapView.setLatLngBounds` and `MLNMapView.clearLatLnBounds`
 * 💥 Breaking: Changed the prefix of files, classes, methods, variables and everything from `MGL` to `MLN`. ([#919](https://github.com/maplibre/maplibre-native/pull/919)).
 
   > To migrate:  

platform/ios/app/MBXViewController.m

@@ -31,6 +31,11 @@ static const MLNCoordinateBounds colorado = {
     .ne = { .latitude = 40.989329, .longitude = -102.062592},
 };
 
+static const MLNCoordinateBounds areaAroundBelgium = {
+    .sw = { .latitude = 52.2782, .longitude = 8.289179999999988},
+    .ne = { .latitude = 48.5584, .longitude = 1.0162300000000073},
+};
+
 static NSString * const MBXViewControllerAnnotationViewReuseIdentifer = @"MBXViewControllerAnnotationViewReuseIdentifer";
 
 typedef NS_ENUM(NSInteger, MBXSettingsSections) {
@@ -99,6 +104,7 @@ typedef NS_ENUM(NSInteger, MBXSettingsRuntimeStylingRows) {
 };
 
 typedef NS_ENUM(NSInteger, MBXSettingsMiscellaneousRows) {
+    MBXSettingsMiscellaneousLatLngBoundsConstraints,
     MBXSettingsMiscellaneousWorldTour,
     MBXSettingsMiscellaneousRandomTour,
     MBXSettingsMiscellaneousScrollView,
@@ -227,6 +233,7 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
     BOOL _isTouringWorld;
     BOOL _contentInsetsEnabled;
     UIEdgeInsets _originalContentInsets;
+    BOOL _hasLatLngBoundConstraints;
 }
 
 // MARK: - Setup & Teardown
@@ -426,6 +433,7 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
             break;
         case MBXSettingsMiscellaneous:
             [settingsTitles addObjectsFromArray:@[
+                _hasLatLngBoundConstraints ? @"Remove LatLng bound constraints" : @"Set LatLng bound box constraint",
                 @"Start World Tour",
                 @"Random Tour",
                 @"Embedded Map View",
@@ -645,6 +653,9 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
         case MBXSettingsMiscellaneous:
             switch (indexPath.row)
             {
+                case MBXSettingsMiscellaneousLatLngBoundsConstraints:
+                    [self setLatLngBoundsConstraints];
+                    break;
                 case MBXSettingsMiscellaneousLocalizeLabels:
                     [self toggleStyleLabelsLanguage];
                     break;
@@ -1451,6 +1462,20 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
     }
 }
 
+-(void)setLatLngBoundsConstraints
+{
+    if(_hasLatLngBoundConstraints) {
+        [self.mapView clearLatLnBounds];
+        [self.mapView resetPosition];
+    } else {
+        MLNMapCamera *newCamera = [self.mapView cameraThatFitsCoordinateBounds: areaAroundBelgium];
+        [self.mapView setCamera: newCamera];
+        [self.mapView setLatLngBounds: areaAroundBelgium];
+    }
+    
+    _hasLatLngBoundConstraints = !_hasLatLngBoundConstraints;
+}
+
 -(void)toggleStyleLabelsLanguage
 {
     _localizingLabels = !_localizingLabels;

platform/ios/src/MLNMapView.h

@@ -1364,6 +1364,18 @@ MLN_EXPORT
  */
 - (CGPoint)anchorPointForGesture:(UIGestureRecognizer *)gesture;
 
+
+/**
+ * Sets a LatLngBounds that constraints map transformations to this bounds.
+ * @param latLngBounds the bounds to constrain the map with
+ */
+- (void)setLatLngBounds:(MLNCoordinateBounds)latLngBounds;
+
+/**
+ * Clears the bounds that were set via `setLatLngBounds`
+ */
+- (void)clearLatLnBounds;
+
 /**
  The distance from the edges of the map view’s frame to the edges of the map
  view’s logical viewport.

platform/ios/src/MLNMapView.mm

@@ -2698,6 +2698,7 @@ public:
     currentCameraOptions.anchor = anchor;
     MLNCoordinateBounds bounds = MLNCoordinateBoundsFromLatLngBounds(self.mbglMap.latLngBoundsForCamera(currentCameraOptions));
     
+    
     return [self cameraThatFitsCoordinateBounds:bounds];
 }
 
@@ -3836,6 +3837,23 @@ static void *windowScreenContext = &windowScreenContext;
     self.mbglMap.setBounds(mbgl::BoundOptions().withMinZoom(minimumZoomLevel));
 }
 
+
+
+- (void)clearLatLnBounds
+{
+    mbgl::BoundOptions newBounds = mbgl::BoundOptions().withLatLngBounds(mbgl::LatLngBounds());
+    self.mbglMap.setBounds(newBounds);
+}
+
+- (void)setLatLngBounds:(MLNCoordinateBounds)latLngBounds
+{
+    mbgl::LatLng sw = {latLngBounds.sw.latitude, latLngBounds.sw.longitude};
+    mbgl::LatLng ne = {latLngBounds.ne.latitude, latLngBounds.ne.longitude};
+    mbgl::BoundOptions newBounds = mbgl::BoundOptions().withLatLngBounds(mbgl::LatLngBounds::hull(sw, ne));
+    
+    self.mbglMap.setBounds(newBounds);
+}
+
 - (double)minimumZoomLevel
 {
     return *self.mbglMap.getBounds().minZoom;