MotionSupport

@MainActor
public struct MotionSupport

This struct provides utility methods for Motion classes.

Additive utility methods


                    
                    
                    register(additiveMotion:)

Registers an Additive motion. Any custom classes that conform to the Additive protocol should register their motion object.

Declaration

Swift

@MainActor
public static func register(additiveMotion motion: any Additive) -> UInt

Parameters


                                additiveMotion

The Additive object to register.

Return Value

An operation ID that should be assigned to the Additive object’s operationID property.


                    
                    
                    unregister(additiveMotion:)

Removes an Additive motion from the registered list. Any custom classes that conform to the Additive protocol should call this method when it has completed its motion.

Declaration

Swift

@MainActor
public static func unregister(additiveMotion motion: any Additive)

Parameters


                                additiveMotion

The Additive object to remove.


                    
                    
                    targetValue(forObject:targetProperty:requestingID:)

Returns the ending value of the most recently started Additive motion operation for the specified object and keyPath. In order to participate in additive motion with other Additive objects, custom objects should use this method to set a starting value.

Example Usage

if let lastTargetValue = MotionSupport.targetValue(forObject: targetObject, targetProperty: property, requestingID: self.operationID) { properties[index].start = lastTargetValue }

Declaration

Swift

@MainActor
public static func targetValue<TargetType>(forObject object: TargetType, targetProperty: PropertyData<TargetType>, requestingID: UInt) -> Double? where TargetType : AnyObject

Parameters

`forObject`	The object whose property value should be queried.
`keyPath`	The keypath of the target property, relative to the object.

Return Value

The ending value. Returns nil if no Additive object is targeting this property.

Utility methods


                    
                    
                    buildPropertyData(keyPath:originalValue:startValue:endValue:isAdditive:)

Builds and returns a PropertyData object using the supplied values.

A PropertyData object will be created if the values you supply pass one of the following tests: 1) there’s a specified start value and that value is different than either the original value or the ending value, or 2) there’s just an original value and that value is different than the ending value, or 3) there’s no start value passed in, which will return a PropertyData object with only an end value. In cases 1 and 2, a PropertyData object with both start and end values will be returned. In the third case, a PropertyData object that only has an ending value will be returned. If all those tests fail, no object will be returned.

Declaration

Swift

@MainActor
public static func buildPropertyData<TargetType, PropertyType>(keyPath: KeyPath<TargetType, PropertyType>, originalValue: PropertyType? = nil, startValue: PropertyType?, endValue: PropertyType, isAdditive: Bool = false) -> PropertyData<TargetType>? where PropertyType : BinaryFloatingPoint

Parameters

`keyPath`	A base `KeyPath` to be used for the `PropertyData`‘s `keyPath` property.
`originalValue`	An optional value representing the current value of the target object property.
`startValue`	An optional value to be supplied to the `PropertyData`‘s `start` property.
`endValue`	A value to be supplied to the `PropertyData`‘s `end` property.
`isAdditive`	Denotes whether this `PropertyData` will be used with an additive Motion. If `true`, optimizations that prevent the `PropertyData` from being built will not occur as it would result in incorrect additive calculations.

Return Value

An optional PropertyData object using the supplied values.


                    
                    
                    buildPropertyData(keyPath:parentPath:originalValue:startValue:endValue:isAdditive:)

Builds and returns a PropertyData object using the supplied values.

Declaration

Swift

@MainActor
public static func buildPropertyData<TargetType, PropertyType, ParentType>(keyPath: KeyPath<TargetType, PropertyType>, parentPath: KeyPath<TargetType, ParentType>? = nil, originalValue: PropertyType? = nil, startValue: PropertyType?, endValue: PropertyType, isAdditive: Bool = false) -> PropertyData<TargetType>? where PropertyType : BinaryFloatingPoint

Parameters

`keyPath`	A base `KeyPath` to be used for the `PropertyData`‘s `keyPath` property.
`parentPath`	A `KeyPath` referencing the parent object to the value being updated.
`originalValue`	An optional value representing the current value of the target object property.
`startValue`	An optional value to be supplied to the `PropertyData`‘s `start` property.
`endValue`	A value to be supplied to the `PropertyData`‘s `end` property.
`isAdditive`	Denotes whether this `PropertyData` will be used with an additive Motion. If `true`, optimizations that prevent the `PropertyData` from being built will not occur as it would result in incorrect additive calculations.

Return Value

An optional PropertyData object using the supplied values.