[ios, macos] Added sort key properties

platform/darwin/src/MGLFillStyleLayer.h

@@ -76,6 +76,23 @@ MGL_EXPORT
  */
 - (instancetype)initWithIdentifier:(NSString *)identifier source:(MGLSource *)source;
 
+#pragma mark - Accessing the Layout Attributes
+
+/**
+ Sorts features in ascending order based on this value. Features with a higher
+ sort key will appear above features with a lower sort key.
+ 
+ You can set this property to an expression containing any of the following:
+ 
+ * Constant numeric values
+ * Predefined functions, including mathematical and string operators
+ * Conditional expressions
+ * Variable assignments and references to assigned variables
+ * Interpolation and step functions applied to the `$zoomLevel` variable and/or
+ feature attributes
+ */
+@property (nonatomic, null_resettable) NSExpression *fillSortKey;
+
 #pragma mark - Accessing the Paint Attributes
 
 /**

platform/darwin/src/MGLFillStyleLayer.mm

@@ -81,6 +81,26 @@ - (NSPredicate *)predicate
     return [NSPredicate mgl_predicateWithFilter:self.rawLayer->getFilter()];
 }
 
+#pragma mark - Accessing the Layout Attributes
+
+- (void)setFillSortKey:(NSExpression *)fillSortKey {
+    MGLAssertStyleLayerIsValid();
+    MGLLogDebug(@"Setting fillSortKey: %@", fillSortKey);
+
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue<mbgl::style::PropertyValue<float>>(fillSortKey, true);
+    self.rawLayer->setFillSortKey(mbglValue);
+}
+
+- (NSExpression *)fillSortKey {
+    MGLAssertStyleLayerIsValid();
+
+    auto propertyValue = self.rawLayer->getFillSortKey();
+    if (propertyValue.isUndefined()) {
+        propertyValue = self.rawLayer->getDefaultFillSortKey();
+    }
+    return MGLStyleValueTransformer<float, NSNumber *>().toExpression(propertyValue);
+}
+
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setFillAntialiased:(NSExpression *)fillAntialiased {

platform/darwin/src/MGLLineStyleLayer.h

@@ -229,6 +229,21 @@ MGL_EXPORT
  */
 @property (nonatomic, null_resettable) NSExpression *lineRoundLimit;
 
+/**
+ Sorts features in ascending order based on this value. Features with a higher
+ sort key will appear above features with a lower sort key.
+ 
+ You can set this property to an expression containing any of the following:
+ 
+ * Constant numeric values
+ * Predefined functions, including mathematical and string operators
+ * Conditional expressions
+ * Variable assignments and references to assigned variables
+ * Interpolation and step functions applied to the `$zoomLevel` variable and/or
+ feature attributes
+ */
+@property (nonatomic, null_resettable) NSExpression *lineSortKey;
+
 #pragma mark - Accessing the Paint Attributes
 
 /**

platform/darwin/src/MGLLineStyleLayer.mm

@@ -167,6 +167,24 @@ - (NSExpression *)lineRoundLimit {
     return MGLStyleValueTransformer<float, NSNumber *>().toExpression(propertyValue);
 }
 
+- (void)setLineSortKey:(NSExpression *)lineSortKey {
+    MGLAssertStyleLayerIsValid();
+    MGLLogDebug(@"Setting lineSortKey: %@", lineSortKey);
+
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue<mbgl::style::PropertyValue<float>>(lineSortKey, true);
+    self.rawLayer->setLineSortKey(mbglValue);
+}
+
+- (NSExpression *)lineSortKey {
+    MGLAssertStyleLayerIsValid();
+
+    auto propertyValue = self.rawLayer->getLineSortKey();
+    if (propertyValue.isUndefined()) {
+        propertyValue = self.rawLayer->getDefaultLineSortKey();
+    }
+    return MGLStyleValueTransformer<float, NSNumber *>().toExpression(propertyValue);
+}
+
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setLineBlur:(NSExpression *)lineBlur {

platform/darwin/test/MGLFillStyleLayerTests.mm

@@ -49,6 +49,75 @@ - (void)testProperties {
     MGLTransition transitionTest = MGLTransitionMake(5, 4);
 
 
+    // fill-sort-key
+    {
+        XCTAssertTrue(rawLayer->getFillSortKey().isUndefined(),
+                      @"fill-sort-key should be unset initially.");
+        NSExpression *defaultExpression = layer.fillSortKey;
+
+        NSExpression *constantExpression = [NSExpression expressionWithFormat:@"1"];
+        layer.fillSortKey = constantExpression;
+        mbgl::style::PropertyValue<float> propertyValue = { 1.0 };
+        XCTAssertEqual(rawLayer->getFillSortKey(), propertyValue,
+                       @"Setting fillSortKey to a constant value expression should update fill-sort-key.");
+        XCTAssertEqualObjects(layer.fillSortKey, constantExpression,
+                              @"fillSortKey should round-trip constant value expressions.");
+
+        constantExpression = [NSExpression expressionWithFormat:@"1"];
+        NSExpression *functionExpression = [NSExpression expressionWithFormat:@"mgl_step:from:stops:($zoomLevel, %@, %@)", constantExpression, @{@18: constantExpression}];
+        layer.fillSortKey = functionExpression;
+
+        {
+            using namespace mbgl::style::expression::dsl;
+            propertyValue = mbgl::style::PropertyExpression<float>(
+                step(zoom(), literal(1.0), 18.0, literal(1.0))
+            );
+        }
+
+        XCTAssertEqual(rawLayer->getFillSortKey(), propertyValue,
+                       @"Setting fillSortKey to a camera expression should update fill-sort-key.");
+        XCTAssertEqualObjects(layer.fillSortKey, functionExpression,
+                              @"fillSortKey should round-trip camera expressions.");
+
+        functionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:(keyName, 'linear', nil, %@)", @{@18: constantExpression}];
+        layer.fillSortKey = functionExpression;
+
+        {
+            using namespace mbgl::style::expression::dsl;
+            propertyValue = mbgl::style::PropertyExpression<float>(
+                interpolate(linear(), number(get("keyName")), 18.0, literal(1.0))
+            );
+        }
+
+        XCTAssertEqual(rawLayer->getFillSortKey(), propertyValue,
+                       @"Setting fillSortKey to a data expression should update fill-sort-key.");
+        NSExpression *pedanticFunctionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:(CAST(keyName, 'NSNumber'), 'linear', nil, %@)", @{@18: constantExpression}];
+        XCTAssertEqualObjects(layer.fillSortKey, pedanticFunctionExpression,
+                              @"fillSortKey should round-trip data expressions.");
+
+        functionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:($zoomLevel, 'linear', nil, %@)", @{@10: functionExpression}];
+        layer.fillSortKey = functionExpression;
+
+        {
+            using namespace mbgl::style::expression::dsl;
+            propertyValue = mbgl::style::PropertyExpression<float>(
+                interpolate(linear(), zoom(), 10.0, interpolate(linear(), number(get("keyName")), 18.0, literal(1.0)))
+            );
+        }
+
+        XCTAssertEqual(rawLayer->getFillSortKey(), propertyValue,
+                       @"Setting fillSortKey to a camera-data expression should update fill-sort-key.");
+        pedanticFunctionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:($zoomLevel, 'linear', nil, %@)", @{@10: pedanticFunctionExpression}];
+        XCTAssertEqualObjects(layer.fillSortKey, pedanticFunctionExpression,
+                              @"fillSortKey should round-trip camera-data expressions.");
+
+        layer.fillSortKey = nil;
+        XCTAssertTrue(rawLayer->getFillSortKey().isUndefined(),
+                      @"Unsetting fillSortKey should return fill-sort-key to the default value.");
+        XCTAssertEqualObjects(layer.fillSortKey, defaultExpression,
+                              @"fillSortKey should return the default value after being unset.");
+    }
+
     // fill-antialias
     {
         XCTAssertTrue(rawLayer->getFillAntialias().isUndefined(),
@@ -470,6 +539,7 @@ - (void)testProperties {
 }
 
 - (void)testPropertyNames {
+    [self testPropertyName:@"fill-sort-key" isBoolean:NO];
     [self testPropertyName:@"is-fill-antialiased" isBoolean:YES];
     [self testPropertyName:@"fill-color" isBoolean:NO];
     [self testPropertyName:@"fill-opacity" isBoolean:NO];

platform/darwin/test/MGLLineStyleLayerTests.mm

@@ -219,6 +219,75 @@ - (void)testProperties {
         XCTAssertThrowsSpecificNamed(layer.lineRoundLimit = functionExpression, NSException, NSInvalidArgumentException, @"MGLLineLayer should raise an exception if a camera-data expression is applied to a property that does not support key paths to feature attributes.");
     }
 
+    // line-sort-key
+    {
+        XCTAssertTrue(rawLayer->getLineSortKey().isUndefined(),
+                      @"line-sort-key should be unset initially.");
+        NSExpression *defaultExpression = layer.lineSortKey;
+
+        NSExpression *constantExpression = [NSExpression expressionWithFormat:@"1"];
+        layer.lineSortKey = constantExpression;
+        mbgl::style::PropertyValue<float> propertyValue = { 1.0 };
+        XCTAssertEqual(rawLayer->getLineSortKey(), propertyValue,
+                       @"Setting lineSortKey to a constant value expression should update line-sort-key.");
+        XCTAssertEqualObjects(layer.lineSortKey, constantExpression,
+                              @"lineSortKey should round-trip constant value expressions.");
+
+        constantExpression = [NSExpression expressionWithFormat:@"1"];
+        NSExpression *functionExpression = [NSExpression expressionWithFormat:@"mgl_step:from:stops:($zoomLevel, %@, %@)", constantExpression, @{@18: constantExpression}];
+        layer.lineSortKey = functionExpression;
+
+        {
+            using namespace mbgl::style::expression::dsl;
+            propertyValue = mbgl::style::PropertyExpression<float>(
+                step(zoom(), literal(1.0), 18.0, literal(1.0))
+            );
+        }
+
+        XCTAssertEqual(rawLayer->getLineSortKey(), propertyValue,
+                       @"Setting lineSortKey to a camera expression should update line-sort-key.");
+        XCTAssertEqualObjects(layer.lineSortKey, functionExpression,
+                              @"lineSortKey should round-trip camera expressions.");
+
+        functionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:(keyName, 'linear', nil, %@)", @{@18: constantExpression}];
+        layer.lineSortKey = functionExpression;
+
+        {
+            using namespace mbgl::style::expression::dsl;
+            propertyValue = mbgl::style::PropertyExpression<float>(
+                interpolate(linear(), number(get("keyName")), 18.0, literal(1.0))
+            );
+        }
+
+        XCTAssertEqual(rawLayer->getLineSortKey(), propertyValue,
+                       @"Setting lineSortKey to a data expression should update line-sort-key.");
+        NSExpression *pedanticFunctionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:(CAST(keyName, 'NSNumber'), 'linear', nil, %@)", @{@18: constantExpression}];
+        XCTAssertEqualObjects(layer.lineSortKey, pedanticFunctionExpression,
+                              @"lineSortKey should round-trip data expressions.");
+
+        functionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:($zoomLevel, 'linear', nil, %@)", @{@10: functionExpression}];
+        layer.lineSortKey = functionExpression;
+
+        {
+            using namespace mbgl::style::expression::dsl;
+            propertyValue = mbgl::style::PropertyExpression<float>(
+                interpolate(linear(), zoom(), 10.0, interpolate(linear(), number(get("keyName")), 18.0, literal(1.0)))
+            );
+        }
+
+        XCTAssertEqual(rawLayer->getLineSortKey(), propertyValue,
+                       @"Setting lineSortKey to a camera-data expression should update line-sort-key.");
+        pedanticFunctionExpression = [NSExpression expressionWithFormat:@"mgl_interpolate:withCurveType:parameters:stops:($zoomLevel, 'linear', nil, %@)", @{@10: pedanticFunctionExpression}];
+        XCTAssertEqualObjects(layer.lineSortKey, pedanticFunctionExpression,
+                              @"lineSortKey should round-trip camera-data expressions.");
+
+        layer.lineSortKey = nil;
+        XCTAssertTrue(rawLayer->getLineSortKey().isUndefined(),
+                      @"Unsetting lineSortKey should return line-sort-key to the default value.");
+        XCTAssertEqualObjects(layer.lineSortKey, defaultExpression,
+                              @"lineSortKey should return the default value after being unset.");
+    }
+
     // line-blur
     {
         XCTAssertTrue(rawLayer->getLineBlur().isUndefined(),
@@ -878,6 +947,7 @@ - (void)testPropertyNames {
     [self testPropertyName:@"line-join" isBoolean:NO];
     [self testPropertyName:@"line-miter-limit" isBoolean:NO];
     [self testPropertyName:@"line-round-limit" isBoolean:NO];
+    [self testPropertyName:@"line-sort-key" isBoolean:NO];
     [self testPropertyName:@"line-blur" isBoolean:NO];
     [self testPropertyName:@"line-color" isBoolean:NO];
     [self testPropertyName:@"line-dash-pattern" isBoolean:NO];

platform/ios/CHANGELOG.md

@@ -4,6 +4,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 
 ## master
 
+* Added the `MGLLineStyleLayer.lineSortKey` and `MGLFillStyleLayer.fillSortKey` properties. ([#179](https://github.com/mapbox/mapbox-gl-native-ios/pull/179))
 * The `-[MGLStyle localizeLabelsIntoLocale:]` and `-[NSExpression mgl_expressionLocalizedIntoLocale:]` methods can now localize text into Traditional Chinese and Vietnamese. ([#173](https://github.com/mapbox/mapbox-gl-native-ios/pull/173))
 
 ## 5.7.0 - February 13, 2020

platform/macos/CHANGELOG.md

@@ -7,6 +7,7 @@
 * Added the `-[MGLMapViewDelegate mapView:shouldRemoveStyleImage:]` method for optimizing style image caching. ([#14769](https://github.com/mapbox/mapbox-gl-native/pull/14769))
 * Added the `image` expression function for converting an image name into a style image. Use this function in expressions in style JSON or with the `MGL_FUNCTION()` syntax in an `NSExpression` format string. ([#15877](https://github.com/mapbox/mapbox-gl-native/pull/15877))
 * Added the `MGLSymbolStyleLayer.textWritingModes` layout property. This property can be set to `MGLTextWritingModeHorizontal` or `MGLTextWritingModeVertical`. ([#14932](https://github.com/mapbox/mapbox-gl-native/pull/14932))
+* Added the `MGLLineStyleLayer.lineSortKey` and `MGLFillStyleLayer.fillSortKey` properties. ([#179](https://github.com/mapbox/mapbox-gl-native-ios/pull/179))
 * The `MGLIdeographicFontFamilyName` Info.plist key now also accepts an array of font family names, to customize font fallback behavior. It can also be set to a Boolean value of `NO` to force the SDK to typeset CJK characters in a remote font specified by `MGLSymbolStyleLayer.textFontNames`. ([#14862](https://github.com/mapbox/mapbox-gl-native/pull/14862)) 
 * The `-[MGLStyle localizeLabelsIntoLocale:]` and `-[NSExpression mgl_expressionLocalizedIntoLocale:]` methods can now localize text into Traditional Chinese and Vietnamese. ([#173](https://github.com/mapbox/mapbox-gl-native-ios/pull/173))
 * Fixed crashes triggered when `MGLSource` and `MGLStyleLayer` objects are accessed after having been invalidated after a style change. ([#15539](https://github.com/mapbox/mapbox-gl-native/pull/15539))