MGLStyleValue


@interface MGLStyleValue <T> : NSObject

An MGLStyleValue object is a generic container for a style attribute value. The layout and paint attribute properties of MGLStyleLayer can be set to MGLStyleValue objects.

The MGLStyleValue class itself represents a class cluster. Under the hood, a particular MGLStyleValue object may be either an MGLConstantStyleValue to represent a constant value or one of the concrete subclasses of MGLStyleFunction to represent a value function. Do not initialize an MGLStyleValue object directly; instead, use one of the class factory methods to create an MGLStyleValue object.

The MGLStyleValue class takes a generic parameter T that indicates the Foundation class being wrapped by this class. Common values for T include:

NSNumber (for Boolean values and floating-point numbers)
NSValue (for CGVector, NSEdgeInsets, UIEdgeInsets, and enumerations)
NSString
NSColor or UIColor
NSArray

Creating a Style Value


                    
                    
                    +valueWithRawValue:

Creates and returns an MGLConstantStyleValue object containing a raw value.

Declaration

Objective-C

+ (nonnull instancetype)valueWithRawValue:(nonnull T)rawValue;

Swift

convenience init(rawValue: T)

Parameters


                                  rawValue

The constant value contained by the object.

Return Value

An MGLConstantStyleValue object containing rawValue, which is treated as a constant value.

View Source on GitHub

Function values


                    
                    
                    +valueWithStops:

Creates and returns an MGLCameraStyleFunction object representing a linear camera function with one or more stops.

Declaration

Objective-C

+ (nonnull instancetype)valueWithStops:
    (nonnull NSDictionary<NSNumber *, MGLStyleValue<T> *> *)stops;

Swift

convenience init(stops: [NSNumber : MGLStyleValue

Parameters


                                  stops

A dictionary associating zoom levels with style values.

Return Value

An MGLCameraStyleFunction object with the given stops.

View Source on GitHub


                    
                    
                    +valueWithInterpolationBase:stops:

Creates and returns an MGLCameraStyleFunction object representing a camera function with an exponential interpolation base and one or more stops.

Declaration

Objective-C

+ (nonnull instancetype)
valueWithInterpolationBase:(CGFloat)interpolationBase
                     stops:(nonnull NSDictionary<NSNumber *, MGLStyleValue<T> *>
                                *)stops;

Swift

convenience init(interpolationBase: CGFloat, stops: [NSNumber : MGLStyleValue

Parameters

`interpolationBase`	The exponential base of the interpolation curve.
`stops`	A dictionary associating zoom levels with style values.

Return Value

An MGLCameraStyleFunction object with the given interpolation base and stops.

View Source on GitHub


                    
                    
                    +valueWithInterpolationMode:cameraStops:options:

Creates and returns an MGLCameraStyleFunction object representing a camera function with one or more stops.

Declaration

Objective-C

+ (nonnull instancetype)
valueWithInterpolationMode:(MGLInterpolationMode)interpolationMode
               cameraStops:
                   (nonnull NSDictionary<id, MGLStyleValue<T> *> *)cameraStops
                   options:(nullable NSDictionary<MGLStyleFunctionOption, id> *)
                               options;

Swift

convenience init(interpolationMode: MGLInterpolationMode, cameraStops: [AnyHashable : MGLStyleValue

Parameters

`interpolationMode`	The mode used to interpolate property values between map zoom level changes.
`cameraStops`	A dictionary associating zoom levels with style values.
`options`	A dictionary containing `MGLStyleFunctionOption` values that specify how a function is applied.

Return Value

An MGLCameraStyleFunction object with the given interpolation mode, camera stops, and options.

View Source on GitHub


                    
                    
                    +valueWithInterpolationMode:sourceStops:attributeName:options:

Creates and returns an MGLSourceStyleFunction object representing a source function.

Declaration

Objective-C

+ (nonnull instancetype)
valueWithInterpolationMode:(MGLInterpolationMode)interpolationMode
               sourceStops:
                   (nullable NSDictionary<id, MGLStyleValue<T> *> *)sourceStops
             attributeName:(nonnull NSString *)attributeName
                   options:(nullable NSDictionary<MGLStyleFunctionOption, id> *)
                               options;

Swift

convenience init(interpolationMode: MGLInterpolationMode, sourceStops: [AnyHashable : MGLStyleValue

Parameters

`interpolationMode`	The mode used to interpolate property values over a range of feature attribute values.
`sourceStops`	A dictionary associating feature attributes with style values.
`attributeName`	Specifies the feature attribute to take as the function input.
`options`	A dictionary containing `MGLStyleFunctionOption` values that specify how a function is applied.

Return Value

An MGLSourceStyleFunction object with the given interpolation mode, source stops, attribute name, and options.

View Source on GitHub


                    
                    
                    +valueWithInterpolationMode:compositeStops:attributeName:options:

Creates and returns an MGLCompositeStyleFunction object representing a composite function.

Declaration

Objective-C

+ (nonnull instancetype)
valueWithInterpolationMode:(MGLInterpolationMode)interpolationMode
            compositeStops:
                (nonnull
                     NSDictionary<id, NSDictionary<id, MGLStyleValue<T> *> *> *)
                    compositeStops
             attributeName:(nonnull NSString *)attributeName
                   options:(nullable NSDictionary<MGLStyleFunctionOption, id> *)
                               options;

Swift

convenience init(interpolationMode: MGLInterpolationMode, compositeStops: [AnyHashable : [AnyHashable : MGLStyleValue

Parameters

`interpolationMode`	The mode used to interpolate property values over a range of feature attribute values for each outer zoom level.
`compositeStops`	A dictionary associating feature attributes with style values.
`attributeName`	Specifies the feature attribute to take as the function input.
`options`	A dictionary containing `MGLStyleFunctionOption` values that specify how a function is applied.

Return Value

An MGLCompositeStyleFunction object with the given interpolation mode, composite stops, attribute name, and options.

View Source on GitHub