wip: implement MGLStyleFunction initializers

platform/darwin/src/MGLStyleValue.h

@@ -189,6 +189,59 @@ MGL_EXPORT
 MGL_EXPORT
 @interface MGLStyleFunction<T> : MGLStyleValue<T>
 
+#pragma mark Creating a Style Function
+
+/**
+ Creates and returns an `MGLStyleFunction` object representing a camera function. 
+ If the function is set as a style layer property value, it will be interpreted 
+ as a camera function with a linear interpolation curve.
+
+ @note Do not create instances of `MGLStyleFunction` unless it is required for
+ backwards compatiblity with your application code. You should create and use
+ instances of `MGLCameraStyleFunction` to specify how properties will
+ be visualized at different zoom levels.
+
+ @param stops A dictionary associating zoom levels with style values.
+ @return An `MGLStyleFunction` object with the given stops.
+ */
++ (instancetype)functionWithStops:(NSDictionary<id, MGLStyleValue<T> *> *)stops __attribute__((deprecated("Use +[MGLStyleValue valueWithInterpolationMode:cameraStops:options:]")));
+
+/**
+ Creates and returns an `MGLStyleFunction` object representing a camera function.
+ If the function is set as a style layer property value, it will be interpreted 
+ as a camera function with an interpolation curve controlled by the provided 
+ interpolation base.
+
+ @note Do not create instances of `MGLStyleFunction` unless it is required for
+ backwards compatiblity with your application code. You should create and use
+ instances of `MGLCameraStyleFunction` to specify how properties will
+ be visualized at different zoom levels.
+
+ @param interpolationBase The exponential base of the interpolation curve.
+ @param stops A dictionary associating zoom levels with style values.
+ @return An `MGLStyleFunction` object with the given interpolation base and stops.
+ */
++ (instancetype)functionWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary<id, MGLStyleValue<T> *> *)stops __attribute__((deprecated("Use +[MGLStyleValue valueWithInterpolationMode:cameraStops:options:]")));
+
+#pragma mark Initializing a Style Function
+
+/**
+ Returns an `MGLStyleFunction` object representing a camera function. If the 
+ function is set as a style layer property value, it will be interpreted
+ as a camera function with an interpolation curve controlled by the provided
+ interpolation base.
+ 
+ @note Do not create instances of `MGLStyleFunction` unless it is required for
+ backwards compatiblity with your application code. You should create and use
+ instances of `MGLCameraStyleFunction` to specify how properties will
+ be visualized at different zoom levels.
+
+ @param interpolationBase The exponential base of the interpolation curve.
+ @param stops A dictionary associating zoom levels with style values.
+ @return An `MGLStyleFunction` object with the given interpolation base and stops.
+ */
+- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary<id, MGLStyleValue<T> *> *)stops NS_DESIGNATED_INITIALIZER;
+
 #pragma mark Accessing the Parameters of a Function
 
 /**
@@ -207,7 +260,8 @@ MGL_EXPORT
  
  @note This property specifies the exponential base of the interpolation curve 
  of `MGLCameraStyleFunction` and `MGLSourceStyleFunction` functions that use 
- a `MGLInterpolationModeExponential` `interpolationMode`.
+ a `MGLInterpolationModeExponential` `interpolationMode`. Otherwise, it is
+ ignored.
  */
 @property (nonatomic) CGFloat interpolationBase;
 

platform/darwin/src/MGLStyleValue.mm

@@ -64,6 +64,45 @@ - (NSUInteger)hash {
 
 @implementation MGLStyleFunction
 
++ (instancetype)functionWithStops:(NSDictionary *)stops {
+ return [[self alloc] initWithInterpolationBase:1.0 stops:stops];
+}
+
++ (instancetype)functionWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
+ return [[self alloc] initWithInterpolationBase:interpolationBase stops:stops];
+}
+
+- (instancetype)init {
+ return [self initWithInterpolationBase:1.0 stops:@{}];
+}
+
+- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
+ if (self = [super init]) {
+ self.interpolationBase = interpolationBase;
+ self.stops = stops;
+ }
+ return self;
+}
+
+- (NSString *)description {
+ return [NSString stringWithFormat:@"<%@: %p, \
+ stops = %@, \
+ interpolationBase = %f>",
+ NSStringFromClass([self class]), (void *)self,
+ self.stops,
+ self.interpolationBase];
+}
+
+- (BOOL)isEqual:(MGLStyleFunction *)other {
+ return ([other isKindOfClass:[self class]]
+ && [other.stops isEqualToDictionary:self.stops]
+ && other.interpolationBase == self.interpolationBase);
+}
+
+- (NSUInteger)hash {
+ return self.stops.hash + self.interpolationBase;
+}
+
 @end
 
 @implementation MGLCameraStyleFunction
@@ -74,8 +113,8 @@ + (instancetype)functionWithInterpolationMode:(MGLInterpolationMode)interpolatio
  return [[self alloc] initWithInterpolationMode:interpolationMode stops:stops options:options];
 }
 
-- (instancetype)init {
- return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:@{} options:nil];
+- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
+ return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:stops options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
 }
 
 - (instancetype)initWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops options:(NSDictionary *)options {
@@ -85,10 +124,8 @@ - (instancetype)initWithInterpolationMode:(MGLInterpolationMode)interpolationMod
  return {};
  }
 
- if (self == [super init]) {
+ if (self == [super initWithInterpolationBase:1.0 stops:stops]) {
  self.interpolationMode = interpolationMode;
- self.stops = stops;
- self.interpolationBase = 1.0;
 
  if ([options.allKeys containsObject:MGLStyleFunctionOptionInterpolationBase]) {
  if ([options[MGLStyleFunctionOptionInterpolationBase] isKindOfClass:[NSNumber class]]) {
@@ -134,16 +171,13 @@ + (instancetype)functionWithInterpolationMode:(MGLInterpolationMode)interpolatio
  return [[self alloc] initWithInterpolationMode:interpolationMode stops:stops attributeName:attributeName options:options];
 }
 
-- (instancetype)init {
- return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:nil attributeName:@"" options:nil];
+- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
+ return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:stops attributeName:@"" options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
 }
 
 - (instancetype)initWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
- if (self == [super init]) {
+ if (self == [super initWithInterpolationBase:1.0 stops:stops]) {
  self.interpolationMode = interpolationMode;
- self.stops = stops;
- self.interpolationBase = 1.0;
-
  _attributeName = attributeName;
 
  if ([options.allKeys containsObject:MGLStyleFunctionOptionDefaultValue]) {
@@ -206,16 +240,13 @@ + (instancetype)functionWithInterpolationMode:(MGLInterpolationMode)interpolatio
  return [[self alloc] initWithInterpolationMode:interpolationMode stops:stops attributeName:attributeName options:options];
 }
 
-- (instancetype)init {
- return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:@{} attributeName:@"" options:nil];
+- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
+ return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:stops attributeName:@"" options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
 }
 
 - (instancetype)initWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
- if (self == [super init]) {
+ if (self == [super initWithInterpolationBase:1.0 stops:stops]) {
  self.interpolationMode = interpolationMode;
- self.stops = stops;
- self.interpolationBase = 1.0;
-
  _attributeName = attributeName;
 
  if ([options.allKeys containsObject:MGLStyleFunctionOptionDefaultValue]) {

platform/darwin/src/MGLStyleValue_Private.h

@@ -60,6 +60,9 @@ class MGLStyleValueTransformer {
  // a deprecated MGLStyleValue method (that used to create an MGLStyleFunction) to create a function
  // for properties that are piecewise-constant (i.e. enum, bool, string)
  return toMBGLIntervalCameraFunction(cameraStyleFunction);
+ } else if ([value isMemberOfClass:[MGLStyleFunction class]]) {
+ MGLStyleFunction<ObjCType> *styleFunction = (MGLStyleFunction<ObjCType> *)value;
+ return toMBGLIntervalCameraFunction(styleFunction);
  } else if (value) {
  [NSException raise:@"MGLAbstractClassException" format:
  @"The style value %@ cannot be applied to the style. "
@@ -81,6 +84,9 @@ class MGLStyleValueTransformer {
 
  if ([value isKindOfClass:[MGLStyleConstantValue class]]) {
  return toMBGLConstantValue((MGLStyleConstantValue<ObjCType> *)value);
+ } else if ([value isMemberOfClass:[MGLStyleFunction class]]) {
+ MGLStyleFunction<ObjCType> *styleFunction = (MGLStyleFunction<ObjCType> *)value;
+ return toMBGLExponentialCameraFunction(styleFunction);
  } else if ([value isKindOfClass:[MGLCameraStyleFunction class]]) {
  MGLCameraStyleFunction<ObjCType> *cameraStyleFunction = (MGLCameraStyleFunction<ObjCType> *)value;
  switch (cameraStyleFunction.interpolationMode) {
@@ -247,6 +253,9 @@ class MGLStyleValueTransformer {
  return {};
  }
  return {};
+ } else if ([value isMemberOfClass:[MGLStyleFunction class]]) {
+ MGLStyleFunction<ObjCType> *styleFunction = (MGLStyleFunction<ObjCType> *)value;
+ return toMBGLExponentialCameraFunction(styleFunction);
  } else if (value) {
  [NSException raise:@"MGLAbstractClassException" format:
  @"The style value %@ cannot be applied to the style. "
@@ -308,25 +317,25 @@ class MGLStyleValueTransformer {
  return mbglValue;
  }
 
- mbgl::style::CameraFunction<MBGLType> toMBGLExponentialCameraFunction(MGLCameraStyleFunction<ObjCType> *cameraStyleFunction) {
+ mbgl::style::CameraFunction<MBGLType> toMBGLExponentialCameraFunction(MGLStyleFunction<ObjCType> *styleFunction) {
  __block std::map<float, MBGLType> stops = {};
- [cameraStyleFunction.stops enumerateKeysAndObjectsUsingBlock:^(NSNumber * _Nonnull zoomKey, MGLStyleValue<ObjCType> * _Nonnull stopValue, BOOL * _Nonnull stop) {
+ [styleFunction.stops enumerateKeysAndObjectsUsingBlock:^(NSNumber * _Nonnull zoomKey, MGLStyleValue<ObjCType> * _Nonnull stopValue, BOOL * _Nonnull stop) {
  NSCAssert([stopValue isKindOfClass:[MGLStyleValue class]], @"Stops should be MGLStyleValues");
  auto mbglStopValue = toPropertyValue(stopValue);
  NSCAssert(mbglStopValue.isConstant(), @"Stops must be constant");
  stops[zoomKey.floatValue] = mbglStopValue.asConstant();
  }];
 
  // Camera function with Exponential stops
- mbgl::style::ExponentialStops<MBGLType> exponentialStops = {stops, (float)cameraStyleFunction.interpolationBase};
+ mbgl::style::ExponentialStops<MBGLType> exponentialStops = {stops, (float)styleFunction.interpolationBase};
  mbgl::style::CameraFunction<MBGLType> cameraFunction = {exponentialStops};
 
  return cameraFunction;
  }
 
- mbgl::style::CameraFunction<MBGLType> toMBGLIntervalCameraFunction(MGLCameraStyleFunction<ObjCType> *cameraStyleFunction) {
+ mbgl::style::CameraFunction<MBGLType> toMBGLIntervalCameraFunction(MGLStyleFunction<ObjCType> *styleFunction) {
  __block std::map<float, MBGLType> stops = {};
- [cameraStyleFunction.stops enumerateKeysAndObjectsUsingBlock:^(NSNumber * _Nonnull zoomKey, MGLStyleValue<ObjCType> * _Nonnull stopValue, BOOL * _Nonnull stop) {
+ [styleFunction.stops enumerateKeysAndObjectsUsingBlock:^(NSNumber * _Nonnull zoomKey, MGLStyleValue<ObjCType> * _Nonnull stopValue, BOOL * _Nonnull stop) {
  NSCAssert([stopValue isKindOfClass:[MGLStyleValue class]], @"Stops should be MGLStyleValues");
  auto mbglStopValue = toPropertyValue(stopValue);
  NSCAssert(mbglStopValue.isConstant(), @"Stops must be constant");

platform/darwin/test/MGLStyleValueTests.swift

@@ -38,6 +38,7 @@ extension MGLStyleValueTests {
  func testDeprecatedFunctions() {
  let shapeSource = MGLShapeSource(identifier: "test", shape: nil, options: nil)
  let symbolStyleLayer = MGLSymbolStyleLayer(identifier: "symbolLayer", source: shapeSource)
+ let circleStyleLayer = MGLCircleStyleLayer(identifier: "circleLayer", source: shapeSource)
 
  // deprecated function, stops with float values
  let iconHaloBlurStyleValue = MGLStyleValue<NSNumber>(interpolationBase: 1.0, stops: [1: MGLStyleValue(rawValue: 0),
@@ -63,6 +64,66 @@ extension MGLStyleValueTests {
  options: nil
  )
  XCTAssertEqual(symbolStyleLayer.iconAllowsOverlap, expectedIconAllowsOverlapStyleValue)
+
+ ///
+ // creating and using MGLStyleFunctions directly
+ ///
+
+ let circleRadiusStops: [NSNumber: MGLStyleValue<NSNumber>] = [
+ 0: MGLStyleValue(rawValue: 10),
+ 20: MGLStyleValue(rawValue: 5)
+ ]
+ let circleRadiusFunction = MGLStyleFunction<NSNumber>(
+ interpolationBase: 1.0,
+ stops: circleRadiusStops
+ )
+ circleStyleLayer.circleRadius = circleRadiusFunction
+ let expectedCircleRadiusFunction = MGLStyleValue<NSNumber>(
+ interpolationMode: .exponential,
+ cameraStops:
+ circleRadiusStops,
+ options: nil
+ )
+ // setting a data driven property to an MGLStyleFunction should return an exponential camera function
+ XCTAssertEqual(circleStyleLayer.circleRadius, expectedCircleRadiusFunction)
+
+ var circleTranslationOne = CGVector(dx: 100, dy: 0)
+ let circleTranslationValueOne = NSValue(bytes: &circleTranslationOne, objCType: "{CGVector=dd}")
+ var circleTranslationTwo = CGVector(dx: 0, dy: 0)
+ let circleTranslationValueTwo = NSValue(bytes: &circleTranslationTwo, objCType: "{CGVector=dd}")
+
+ let circleTranslationStops = [
+ 0: MGLStyleValue<NSValue>(rawValue: circleTranslationValueOne),
+ 10: MGLStyleValue<NSValue>(rawValue: circleTranslationValueTwo)
+ ]
+ let circleTranslationFunction = MGLStyleFunction(
+ interpolationBase: 1.0,
+ stops: circleTranslationStops
+ )
+ circleStyleLayer.circleTranslation = circleTranslationFunction
+ let expectedCircleTranslationFunction = MGLStyleValue<NSValue>(
+ interpolationMode: .exponential,
+ cameraStops: circleTranslationStops,
+ options: nil
+ )
+ // setting a non-data driven, interpolatable property to an MGLStyleFunction should return an exponential camera function
+ XCTAssertEqual(circleStyleLayer.circleTranslation, expectedCircleTranslationFunction)
+
+ let iconOptionalStops: [NSNumber: MGLStyleValue<NSNumber>] = [
+ 0: MGLStyleValue(rawValue: false),
+ 20: MGLStyleValue(rawValue: true)
+ ]
+ let iconOptionalFunction = MGLStyleFunction(
+ interpolationBase: 1.0,
+ stops: iconOptionalStops
+ )
+ symbolStyleLayer.iconOptional = iconOptionalFunction
+ let expectedIconOptionalFunction = MGLStyleValue(
+ interpolationMode: .interval,
+ cameraStops: iconOptionalStops,
+ options: nil
+ )
+ XCTAssertEqual(symbolStyleLayer.iconOptional, expectedIconOptionalFunction)
  }
 
  func testFunctionsWithNonDataDrivenProperties() {