MGLStyleLayer predicates (filters)

platform/darwin/src/MGLBaseStyleLayer_Private.h

@@ -1,5 +1,7 @@
 #import "MGLBaseStyleLayer.h"
 
+#import "NSPredicate+MGLAdditions.h"
+
 @interface MGLBaseStyleLayer (MGLBaseStyleLayer_Private)
 
 - (void)update;

platform/darwin/src/MGLCircleStyleLayer.h

@@ -18,6 +18,14 @@ typedef NS_ENUM(NSUInteger, MGLCircleStyleLayerCirclePitchScale) {
 
 @interface MGLCircleStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+/**
+ A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
+
+ The predicate's left expression must be a string that identifies a feature
+ property, or one of the special keys.
+ */
+@property (nonatomic, nullable) NSPredicate *predicate;
+
 #pragma mark - Accessing the Paint Attributes
 
 /**

platform/darwin/src/MGLCircleStyleLayer.mm

@@ -29,6 +29,16 @@ - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdenti
     return self;
 }
 
+- (void)setPredicate:(NSPredicate *)predicate
+{
+    self.layer->setFilter(predicate.mgl_filter);
+}
+
+- (NSPredicate *)predicate
+{
+    return [NSPredicate mgl_predicateWithFilter:self.layer->getFilter()];
+}
+
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setCircleRadius:(id <MGLStyleAttributeValue, MGLStyleAttributeValue_Private>)circleRadius {

platform/darwin/src/MGLFeature.mm

@@ -3,6 +3,7 @@
 #import "MGLPointAnnotation.h"
 #import "MGLPolyline.h"
 #import "MGLPolygon.h"
+#import "MGLValueEvaluator.h"
 
 #import "MGLMultiPoint_Private.h"
 
@@ -113,51 +114,7 @@ - (id)attributeForKey:(NSString *)key {
 
 @end
 
-/**
- Recursively transforms a C++ type into the corresponding Foundation type.
- */
-class PropertyValueEvaluator {
-public:
-    id operator()(const mbgl::NullValue &) const {
-        return [NSNull null];
-    }
-
-    id operator()(const bool &value) const {
-        return value ? @YES : @NO;
-    }
-
-    id operator()(const uint64_t &value) const {
-        return @(value);
-    }
-
-    id operator()(const int64_t &value) const {
-        return @(value);
-    }
-
-    id operator()(const double &value) const {
-        return @(value);
-    }
-
-    id operator()(const std::string &value) const {
-        return @(value.c_str());
-    }
-
-    id operator()(const std::vector<mbgl::Value> &values) const {
-        NSMutableArray *objects = [NSMutableArray arrayWithCapacity:values.size()];
-        for (const auto &v : values) {
-            [objects addObject:mbgl::Value::visit(v, *this)];
-        }
-        return objects;
-    }
-
-    id operator()(const std::unordered_map<std::string, mbgl::Value> &items) const {
-        NSMutableDictionary *attributes = [NSMutableDictionary dictionaryWithCapacity:items.size()];
-        for (auto &item : items) {
-            attributes[@(item.first.c_str())] = mbgl::Value::visit(item.second, *this);
-        }
-        return attributes;
-    }
-};
+
 
 /**
  Transforms an `mbgl::geometry::geometry` type into an instance of the
@@ -253,14 +210,14 @@ static CLLocationCoordinate2D toLocationCoordinate2D(const mbgl::Point<T> &point
         NSMutableDictionary *attributes = [NSMutableDictionary dictionaryWithCapacity:feature.properties.size()];
         for (auto &pair : feature.properties) {
             auto &value = pair.second;
-            PropertyValueEvaluator evaluator;
+            ValueEvaluator evaluator;
             attributes[@(pair.first.c_str())] = mbgl::Value::visit(value, evaluator);
         }
 
         GeometryEvaluator<double> evaluator;
         MGLShape <MGLFeaturePrivate> *shape = mapbox::geometry::geometry<double>::visit(feature.geometry, evaluator);
         if (feature.id) {
-            shape.identifier = mbgl::FeatureIdentifier::visit(*feature.id, PropertyValueEvaluator());
+            shape.identifier = mbgl::FeatureIdentifier::visit(*feature.id, ValueEvaluator());
         }
         shape.attributes = attributes;
         [shapes addObject:shape];

platform/darwin/src/MGLFillStyleLayer.h

@@ -13,6 +13,14 @@ typedef NS_ENUM(NSUInteger, MGLFillStyleLayerFillTranslateAnchor) {
 
 @interface MGLFillStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+/**
+ A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
+
+ The predicate's left expression must be a string that identifies a feature
+ property, or one of the special keys.
+ */
+@property (nonatomic, nullable) NSPredicate *predicate;
+
 #pragma mark - Accessing the Paint Attributes
 
 /**

platform/darwin/src/MGLFillStyleLayer.mm

@@ -29,6 +29,16 @@ - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdenti
     return self;
 }
 
+- (void)setPredicate:(NSPredicate *)predicate
+{
+    self.layer->setFilter(predicate.mgl_filter);
+}
+
+- (NSPredicate *)predicate
+{
+    return [NSPredicate mgl_predicateWithFilter:self.layer->getFilter()];
+}
+
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setFillAntialias:(id <MGLStyleAttributeValue, MGLStyleAttributeValue_Private>)fillAntialias {

platform/darwin/src/MGLLineStyleLayer.h

@@ -25,6 +25,14 @@ typedef NS_ENUM(NSUInteger, MGLLineStyleLayerLineTranslateAnchor) {
 
 @interface MGLLineStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+/**
+ A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
+
+ The predicate's left expression must be a string that identifies a feature
+ property, or one of the special keys.
+ */
+@property (nonatomic, nullable) NSPredicate *predicate;
+
 #pragma mark - Accessing the Layout Attributes
 
 /**

platform/darwin/src/MGLLineStyleLayer.mm

@@ -29,6 +29,16 @@ - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdenti
     return self;
 }
 
+- (void)setPredicate:(NSPredicate *)predicate
+{
+    self.layer->setFilter(predicate.mgl_filter);
+}
+
+- (NSPredicate *)predicate
+{
+    return [NSPredicate mgl_predicateWithFilter:self.layer->getFilter()];
+}
+
 #pragma mark - Accessing the Layout Attributes
 
 - (void)setLineCap:(id <MGLStyleAttributeValue, MGLStyleAttributeValue_Private>)lineCap {

platform/darwin/src/MGLStyleLayer.h.ejs

@@ -35,6 +35,16 @@ typedef NS_ENUM(NSUInteger, MGL<%- camelize(type) %>StyleLayer<%- camelize(prope
 <% } -%>
 @interface MGL<%- camelize(type) %>StyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+<% if (type !== 'background' && type !== 'raster') { -%>
+/**
+ A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
+
+ The predicate's left expression must be a string that identifies a feature
+ property, or one of the special keys.
+ */
+@property (nonatomic, nullable) NSPredicate *predicate;
+
+<% } -%>
 <% if (layoutProperties.length) { -%>
 #pragma mark - Accessing the Layout Attributes
 
@@ -53,6 +63,7 @@ typedef NS_ENUM(NSUInteger, MGL<%- camelize(type) %>StyleLayer<%- camelize(prope
 
 <% } -%>
 <% } -%>
+<% if (paintProperties.length) { -%>
 #pragma mark - Accessing the Paint Attributes
 
 <% for (const property of paintProperties) { -%>
@@ -68,6 +79,7 @@ typedef NS_ENUM(NSUInteger, MGL<%- camelize(type) %>StyleLayer<%- camelize(prope
  */
 @property (nonatomic<% if (!property.required) { %>, null_resettable<% } %>) <%- propertyType(property, false, type) %> <%- camelizeWithLeadingLowercase(property.name) %>;
 
+<% } -%>
 <% } -%>
 @end
 

platform/darwin/src/MGLStyleLayer.mm.ejs

@@ -34,6 +34,18 @@
     return self;
 }
 
+<% if (type !== 'background' && type !== 'raster') { -%>
+- (void)setPredicate:(NSPredicate *)predicate
+{
+    self.layer->setFilter(predicate.mgl_filter);
+}
+
+- (NSPredicate *)predicate
+{
+    return [NSPredicate mgl_predicateWithFilter:self.layer->getFilter()];
+}
+
+<% } -%>
 <% if (layoutProperties.length) { -%>
 #pragma mark - Accessing the Layout Attributes
 

platform/darwin/src/MGLSymbolStyleLayer.h

@@ -69,6 +69,14 @@ typedef NS_ENUM(NSUInteger, MGLSymbolStyleLayerTextTranslateAnchor) {
 
 @interface MGLSymbolStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+/**
+ A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
+
+ The predicate's left expression must be a string that identifies a feature
+ property, or one of the special keys.
+ */
+@property (nonatomic, nullable) NSPredicate *predicate;
+
 #pragma mark - Accessing the Layout Attributes
 
 /**

platform/darwin/src/MGLSymbolStyleLayer.mm

@@ -29,6 +29,16 @@ - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdenti
     return self;
 }
 
+- (void)setPredicate:(NSPredicate *)predicate
+{
+    self.layer->setFilter(predicate.mgl_filter);
+}
+
+- (NSPredicate *)predicate
+{
+    return [NSPredicate mgl_predicateWithFilter:self.layer->getFilter()];
+}
+
 #pragma mark - Accessing the Layout Attributes
 
 - (void)setSymbolPlacement:(id <MGLStyleAttributeValue, MGLStyleAttributeValue_Private>)symbolPlacement {

platform/darwin/src/MGLValueEvaluator.h

@@ -0,0 +1,49 @@
+#import <Foundation/Foundation.h>
+
+#import <mbgl/util/geometry.hpp>
+
+/**
+ Recursively transforms a C++ type into the corresponding Foundation type.
+ */
+class ValueEvaluator {
+public:
+    id operator()(const mbgl::NullValue &) const {
+        return [NSNull null];
+    }
+
+    id operator()(const bool &value) const {
+        return value ? @YES : @NO;
+    }
+
+    id operator()(const uint64_t &value) const {
+        return @(value);
+    }
+
+    id operator()(const int64_t &value) const {
+        return @(value);
+    }
+
+    id operator()(const double &value) const {
+        return @(value);
+    }
+
+    id operator()(const std::string &value) const {
+        return @(value.c_str());
+    }
+
+    id operator()(const std::vector<mbgl::Value> &values) const {
+        NSMutableArray *objects = [NSMutableArray arrayWithCapacity:values.size()];
+        for (const auto &v : values) {
+            [objects addObject:mbgl::Value::visit(v, *this)];
+        }
+        return objects;
+    }
+
+    id operator()(const std::unordered_map<std::string, mbgl::Value> &items) const {
+        NSMutableDictionary *attributes = [NSMutableDictionary dictionaryWithCapacity:items.size()];
+        for (auto &item : items) {
+            attributes[@(item.first.c_str())] = mbgl::Value::visit(item.second, *this);
+        }
+        return attributes;
+    }
+};

platform/darwin/src/NSComparisonPredicate+MGLAdditions.h

@@ -0,0 +1,7 @@
+#import <Foundation/Foundation.h>
+
+#include <mbgl/style/filter.hpp>
+
+@interface NSComparisonPredicate (MGLAdditions)
+
+@end

platform/darwin/src/NSComparisonPredicate+MGLAdditions.mm

@@ -0,0 +1,67 @@
+#import "NSComparisonPredicate+MGLAdditions.h"
+
+#import "NSPredicate+MGLAdditions.h"
+#import "NSExpression+MGLAdditions.h"
+
+@implementation NSComparisonPredicate (MGLAdditions)
+
+- (mbgl::style::Filter)mgl_filter
+{
+    switch (self.predicateOperatorType) {
+        case NSEqualToPredicateOperatorType: {
+            auto filter = mbgl::style::EqualsFilter();
+            filter.key = self.leftExpression.keyPath.UTF8String;
+            filter.value = self.rightExpression.mgl_filterValue;
+            return filter;
+        }
+        case NSNotEqualToPredicateOperatorType: {
+            auto filter = mbgl::style::NotEqualsFilter();
+            filter.key = self.leftExpression.keyPath.UTF8String;
+            filter.value = self.rightExpression.mgl_filterValue;
+            return filter;
+        }
+        case NSGreaterThanPredicateOperatorType: {
+            auto filter = mbgl::style::GreaterThanFilter();
+            filter.key = self.leftExpression.keyPath.UTF8String;
+            filter.value = self.rightExpression.mgl_filterValue;
+            return filter;
+        }
+        case NSGreaterThanOrEqualToPredicateOperatorType: {
+            auto filter = mbgl::style::GreaterThanEqualsFilter();
+            filter.key = self.leftExpression.keyPath.UTF8String;
+            filter.value = self.rightExpression.mgl_filterValue;
+            return filter;
+        }
+        case NSLessThanPredicateOperatorType: {
+            auto filter = mbgl::style::LessThanFilter();
+            filter.key = self.leftExpression.keyPath.UTF8String;
+            filter.value = self.rightExpression.mgl_filterValue;
+            return filter;
+        }
+        case NSLessThanOrEqualToPredicateOperatorType: {
+            auto filter = mbgl::style::LessThanEqualsFilter();
+            filter.key = self.leftExpression.keyPath.UTF8String;
+            filter.value = self.rightExpression.mgl_filterValue;
+            return filter;
+        }
+        case NSInPredicateOperatorType: {
+            auto filter = mbgl::style::InFilter();
+            filter.key = self.leftExpression.keyPath.UTF8String;
+            filter.values = self.rightExpression.mgl_filterValues;
+            return filter;
+        }
+        case NSMatchesPredicateOperatorType:
+        case NSLikePredicateOperatorType:
+        case NSBeginsWithPredicateOperatorType:
+        case NSEndsWithPredicateOperatorType:
+        case NSCustomSelectorPredicateOperatorType:
+        case NSContainsPredicateOperatorType:
+        case NSBetweenPredicateOperatorType:
+            [NSException raise:@"Unsupported operator type"
+                        format:@"NSPredicateOperatorType:%lu is not supported.", (unsigned long)self.predicateOperatorType];
+    }
+
+    return {};
+}
+
+@end

platform/darwin/src/NSCompoundPredicate+MGLAdditions.h

@@ -0,0 +1,7 @@
+#import <Foundation/Foundation.h>
+
+#include <mbgl/style/filter.hpp>
+
+@interface NSCompoundPredicate (MGLAdditions)
+
+@end