initial featuresAt implementation (merged master into 352-featuresAt)

include/mbgl/darwin/MGLTypes.h

@@ -27,6 +27,15 @@ typedef NS_ENUM(NSUInteger, MGLUserTrackingMode) {
     MGLUserTrackingModeFollowWithCourse,
 };
 
+/** The style layer name for a queried map feature. */
+extern NSString * const MGLFeatureLayerNameKey;
+
+/** The style source name for a queried map feature. */
+extern NSString * const MGLFeatureSourceNameKey;
+
+/** The properties from the source data for a queried map feature. */
+extern NSString * const MGLFeaturePropertiesKey;
+
 NS_ASSUME_NONNULL_END
 
 #pragma clang diagnostic push

include/mbgl/ios/MGLMapView.h

@@ -174,6 +174,14 @@ IB_DESIGNABLE
  */
 @property (nonatomic, readonly) UIButton *attributionButton;
 
+/** Query the visible map for features at a given point. 
+*
+*   @param point A point on screen, for example at a user gesture.
+*   @param radius A distance in screen points around which to query features.
+*   @return An array of `NSDictionary` objects representing features near the point. Keys and values provided include `MGLFeatureLayerNameKey` for the feature layer name in the active style, `MGLFeatureSourceNameKey` for the feature source name in the active style, and `MGLFeaturePropertiesKey` containing a dictionary of properties of the feature from the source data as `NSString` keys and values. */
+- (NS_ARRAY_OF(NSDictionary *) *)featureDescriptionsAtPoint:(CGPoint)point radius:(CGFloat)radius;
+
+#pragma mark - Accessing the Delegate
 /** 
  Currently active style classes, represented as an array of string identifiers.
  */

include/mbgl/map/map.hpp

@@ -8,6 +8,7 @@
 #include <mbgl/util/geo.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/vec.hpp>
+#include <mbgl/util/interactive_features.hpp>
 #include <mbgl/annotation/annotation.hpp>
 #include <mbgl/style/types.hpp>
 
@@ -166,6 +167,7 @@ class Map : private util::noncopyable {
 
     AnnotationIDs getPointAnnotationsInBounds(const LatLngBounds&);
 
+    // Style API
     void addCustomLayer(const std::string& id,
                         CustomLayerInitializeFunction,
                         CustomLayerRenderFunction,
@@ -174,6 +176,9 @@ class Map : private util::noncopyable {
                         const char* before = nullptr);
     void removeCustomLayer(const std::string& id);
 
+    // Features
+    std::vector<FeatureDescription> featureDescriptionsAt(const PrecisionPoint, const uint16_t radius = 0) const;
+
     // Memory
     void setSourceTileCacheSize(size_t);
     void onLowMemory();

include/mbgl/util/interactive_features.hpp

@@ -0,0 +1,20 @@
+#ifndef MBGL_UTIL_INTERACTIVE_FEATURES
+#define MBGL_UTIL_INTERACTIVE_FEATURES
+
+#include <map>
+#include <string>
+
+namespace mbgl {
+
+struct FeatureDescription {
+    inline explicit FeatureDescription(std::string layer_, std::string source_, std::map<std::string, std::string>properties_)
+    : layer(layer_), source(source_), properties(properties_) {}
+
+    std::string layer;
+    std::string source;
+    std::map<std::string, std::string> properties;
+};
+
+}
+
+#endif

ios/app/MBXViewController.mm

@@ -21,6 +21,8 @@ @interface MBXViewController () <UIActionSheetDelegate, MGLMapViewDelegate>
 
 @property (nonatomic) MGLMapView *mapView;
 @property (nonatomic) NSUInteger styleIndex;
+@property (nonatomic) UIView *interactiveShield;
+@property (nonatomic) UITextView *featuresView;
 
 @end
 
@@ -175,6 +177,7 @@ - (void)showSettings
                                                                  : @"Show Custom Style Layer"),
                                                                 @"Print Telemetry Logfile",
                                                                 @"Delete Telemetry Logfile",
+                                                                @"Enable Interactivity",
                                                                 nil];
 
     [sheet showFromBarButtonItem:self.navigationItem.leftBarButtonItem animated:YES];
@@ -326,6 +329,35 @@ - (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSIn
             }
         }
     }
+    else if (buttonIndex == actionSheet.firstOtherButtonIndex + 16)
+    {
+        if ([self.mapView.styleURL.scheme isEqualToString:@"mapbox"])
+        {
+            self.mapView.userInteractionEnabled = NO;
+
+            self.interactiveShield = [[UIView alloc] initWithFrame:self.mapView.frame];
+            self.interactiveShield.backgroundColor = [UIColor clearColor];
+            self.interactiveShield.userInteractionEnabled = YES;
+            [self.view insertSubview:self.interactiveShield aboveSubview:self.mapView];
+
+            UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handleInteractivityPan:)];
+            [self.interactiveShield addGestureRecognizer:pan];
+
+            self.featuresView = [[UITextView alloc] initWithFrame:CGRectMake(20, self.topLayoutGuide.length + 20,
+                                                                             self.view.bounds.size.width / 2 - 40, self.view.bounds.size.height / 4)];
+            self.featuresView.selectable = NO;
+            self.featuresView.font = [UIFont systemFontOfSize:16];
+            self.featuresView.backgroundColor = [UIColor whiteColor];
+            self.featuresView.alpha = 0.75;
+            self.featuresView.text = @"Moving the map is now disabled until you change the style. Pan with your finger to query for features.";
+
+            [self.view addSubview:self.featuresView];
+
+            self.mapView.styleURL = [NSURL URLWithString:@"asset://streets-interactive-poi-v8.json"];
+
+            [(UIButton *)self.navigationItem.titleView setTitle:@"Interactive Streets" forState:UIControlStateNormal];
+        }
+    }
 }
 
 - (void)parseFeaturesAddingCount:(NSUInteger)featuresCount
@@ -455,8 +487,84 @@ - (void)handleLongPress:(UILongPressGestureRecognizer *)longPress
     }
 }
 
+- (void)handleInteractivityPan:(UIPanGestureRecognizer *)pan
+{
+    if (pan.state == UIGestureRecognizerStateBegan || pan.state == UIGestureRecognizerStateChanged)
+    {
+        self.featuresView.userInteractionEnabled = NO;
+
+        CGPoint point = [pan locationInView:pan.view];
+
+        NSArray *features = [self.mapView featureDescriptionsAtPoint:point radius:50];
+
+        if ([features count])
+        {
+            NSMutableArray *outputNames = [NSMutableArray array];
+            NSMutableArray *seenIDs = [NSMutableArray array];
+
+            for (NSDictionary *feature in features)
+            {
+                NSDictionary *properties = feature[MGLFeaturePropertiesKey];
+
+                NSString *featureID = properties[@"osm_id"];
+
+                if ( ! [seenIDs containsObject:featureID])
+                {
+                    [seenIDs addObject:featureID];
+
+                    NSString *featureName = properties[@"name_en"];
+
+                    // Mapbox-returned OSM IDs have 1 + zero padding in front of
+                    // the actual OSM ID, so let's remove that.
+                    //
+                    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"^10+(.*)"
+                                                                                           options:0
+                                                                                             error:nil];
+
+                    featureID = [regex stringByReplacingMatchesInString:featureID
+                                                                options:0
+                                                                  range:NSMakeRange(0, featureID.length)
+                                                           withTemplate:@"$1"];
+
+                    [outputNames addObject:[NSString stringWithFormat:@"- %@ (OSM #%@)", featureName, featureID]];
+                }
+            }
+
+            NSMutableString *output = [NSMutableString stringWithString:@"Features:\n\n"];
+
+            for (NSString *outputName in outputNames)
+            {
+                [output appendString:outputName];
+                [output appendString:@"\n"];
+            }
+
+            self.featuresView.text = output;
+            self.featuresView.contentOffset = CGPointZero;
+        }
+        else
+        {
+            self.featuresView.text = nil;
+        }
+    }
+    else
+    {
+        self.featuresView.userInteractionEnabled = YES;
+    }
+}
+
 - (void)cycleStyles
 {
+    if (self.interactiveShield)
+    {
+        [self.interactiveShield removeFromSuperview];
+        self.interactiveShield = nil;
+
+        [self.featuresView removeFromSuperview];
+        self.featuresView = nil;
+
+        self.mapView.userInteractionEnabled = YES;
+    }
+
     UIButton *titleButton = (UIButton *)self.navigationItem.titleView;
 
     self.styleIndex = (self.styleIndex + 1) % mbgl::util::default_styles::numOrderedStyles;

ios/app/mapboxgl-app.gypi

@@ -16,6 +16,7 @@
         './threestates.geojson',
         './Settings.bundle/',
         './app-info.plist',
+        './streets-interactive-poi-v8.json',
       ],
 
       'dependencies': [
@@ -63,7 +64,7 @@
           },
         },
       },
-      
+
       'copies': [
         {
           'destination': '<(PRODUCT_DIR)/$(FRAMEWORKS_FOLDER_PATH)',