Blockly Framework Reference

LayoutEngine

@objcMembers open class LayoutEngine: NSObject

Core object that is required by Layout instances in order to provide:

• Unit scaling between Blockly’s Workspace coordinate system and the UIView coordinate system
• UI configuration

All Layout instances in a single Layout tree should share the same single instance of LayoutEngine. If any of the nodes in a single tree use different instances of LayoutEngine, unexpected results may occur.

Properties

• minimumScale

  The minimum scale that the engine can have, relative to the Workspace coordinate system.

  Declaration

  Swift

  public fileprivate(set) final var minimumScale: CGFloat = 0.5

• maximumScale

  The maximum scale that the engine can have, relative to the Workspace coordinate system.

  Declaration

  Swift

  public fileprivate(set) final var maximumScale: CGFloat = 2.0

• scale

  The current scale of the UI, relative to the Workspace coordinate system. eg. scale = 2.0 means that a (10, 10) UIView point scales to a (5, 5) Workspace point.

  Declaration

  Swift

  public final var scale: CGFloat = 1.0

• popoverScale

  The scale that should be used inside popovers

  Declaration

  Swift

  public final var popoverScale: CGFloat

• rtl

  Flag determining if Layout instances associated with this layout engine should be rendered in right-to-left (true) or left-to-right (false)..

  Declaration

  Swift

  public final var rtl: Bool

• config

  The UI configuration to use for this layout engine

  Declaration

  Swift

  public final var config: LayoutConfig

Initializers

• init(config:rtl:minimumScale:maximumScale:)

  Creates a LayoutEngine instance.

  Declaration

  Swift

  public init(
      config: LayoutConfig = LayoutConfig(), rtl: Bool? = nil, minimumScale: CGFloat = 0.5,
      maximumScale: CGFloat = 2.0)

Public

• scaledWorkspaceVectorFromViewVector(_:)

  Using the current scale value, this method scales a point from the UIView coordinate system to the Workspace coordinate system.

  Note

  This does not translate a UIView point directly into a Workspace point, it only scales the magnitude of a UIView point into the Workspace coordinate system. For example, in RTL, more calculation would need to be done to get the UIView point’s translated Workspace point.

  Declaration

  Swift

  public final func scaledWorkspaceVectorFromViewVector(_ point: CGPoint) -> WorkspacePoint

  Return Value

  A point in the Workspace coordinate system.

• workspaceSizeFromViewSize(_:)

  Using the current scale value, this method scales a size from the UIView coordinate system to the Workspace coordinate system.

  Declaration

  Swift

  public final func workspaceSizeFromViewSize(_ size: CGSize) -> WorkspaceSize

  Return Value

  A size in the Workspace coordinate system.

• workspaceUnitFromViewUnit(_:)

  Using the current scale value, this method scales a unit value from the UIView coordinate system to the Workspace coordinate system.

  Declaration

  Swift

  public final func workspaceUnitFromViewUnit(_ unit: CGFloat) -> CGFloat

  Return Value

  A unit value in the Workspace coordinate system.

• viewUnitFromWorkspaceUnit(_:)

  Using the current scale value, this method scales a unit value from the Workspace coordinate system to the UIView coordinate system.

  Declaration

  Swift

  public final func viewUnitFromWorkspaceUnit(_ unit: CGFloat) -> CGFloat

  Return Value

  A unit value in the UIView coordinate system.

• viewPointFromWorkspacePoint(_:)

  Using the current scale value, this method scales a left-to-right point from the Workspace coordinate system to the UIView coordinate system.

  Declaration

  Swift

  public final func viewPointFromWorkspacePoint(_ point: WorkspacePoint) -> CGPoint

  Return Value

  A point in the UIView coordinate system.

• viewPointFromWorkspacePoint(_:_:)

  Using the current scale value, this method scales a (x, y) point from the Workspace coordinate system to the UIView coordinate system.

  Declaration

  Swift

  public final func viewPointFromWorkspacePoint(_ x: CGFloat, _ y: CGFloat) -> CGPoint

  Return Value

  A point in the UIView coordinate system.

• viewSizeFromWorkspaceSize(_:)

  Using the current scale value, this method scales a size from the Workspace coordinate system to the UIView coordinate system.

  Declaration

  Swift

  public final func viewSizeFromWorkspaceSize(_ size: WorkspaceSize) -> CGSize

  Return Value

  A size in the UIView coordinate system.