LayoutRef

public struct LayoutRef : LayoutProtocol, GWeakCapturing

A PangoLayout structure represents an entire paragraph of text.

While complete access to the layout capabilities of Pango is provided using the detailed interfaces for itemization and shaping, using that functionality directly involves writing a fairly large amount of code. PangoLayout provides a high-level driver for formatting entire paragraphs of text at once. This includes paragraph-level functionality such as line breaking, justification, alignment and ellipsization.

A PangoLayout is initialized with a PangoContext, UTF-8 string and set of attributes for that string. Once that is done, the set of formatted lines can be extracted from the object, the layout can be rendered, and conversion between logical character positions within the layout’s text, and the physical position of the resulting glyphs can be made.

There are a number of parameters to adjust the formatting of a PangoLayout. The following image shows adjustable parameters (on the left) and font metrics (on the right):

<picture> <source srcset=“layout-dark.png” media=“(prefers-color-scheme: dark)”> <img alt=“Pango Layout Parameters” src=“layout-light.png”> </picture>

The following images demonstrate the effect of alignment and justification on the layout of text:
align=left align=left, justify
align=center align=center, justify
align=right align=right, justify

It is possible, as well, to ignore the 2-D setup, and simply treat the results of a PangoLayout as a list of lines.

The LayoutRef type acts as a lightweight Swift reference to an underlying PangoLayout instance. It exposes methods that can operate on this data type through LayoutProtocol conformance. Use LayoutRef only as an unowned reference to an existing PangoLayout instance.

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  • ptr 
    Untyped pointer to the underlying `PangoLayout` instance.

    For type-safe access, use the generated, typed pointer layout_ptr property instead.

    Declaration

    Swift

    public let ptr: UnsafeMutableRawPointer!
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Layout Class

  • Designated initialiser from the underlying C data type

    Declaration

    Swift

    @inlinable
init(_ p: UnsafeMutablePointer<PangoLayout>)
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  • Designated initialiser from a constant pointer to the underlying C data type

    Declaration

    Swift

    @inlinable
init(_ p: UnsafePointer<PangoLayout>)
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  • Conditional initialiser from an optional pointer to the underlying C data type

    Declaration

    Swift

    @inlinable
init!(_ maybePointer: UnsafeMutablePointer<PangoLayout>?)
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  • Conditional initialiser from an optional, non-mutable pointer to the underlying C data type

    Declaration

    Swift

    @inlinable
init!(_ maybePointer: UnsafePointer<PangoLayout>?)
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  • Conditional initialiser from an optional gpointer

    Declaration

    Swift

    @inlinable
init!(gpointer g: gpointer?)
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  • Conditional initialiser from an optional, non-mutable gconstpointer

    Declaration

    Swift

    @inlinable
init!(gconstpointer g: gconstpointer?)
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  • Reference intialiser for a related type that implements LayoutProtocol

    Declaration

    Swift

    @inlinable
init<T>(_ other: T) where T : LayoutProtocol
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  • This factory is syntactic sugar for setting weak pointers wrapped in GWeak<T>

    Declaration

    Swift

    @inlinable
static func unowned<T>(_ other: T) -> LayoutRef where T : LayoutProtocol
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  • Unsafe typed initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
init<T>(cPointer: UnsafeMutablePointer<T>)
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  • Unsafe typed initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
init<T>(constPointer: UnsafePointer<T>)
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  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
init(mutating raw: UnsafeRawPointer)
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  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
init(raw: UnsafeMutableRawPointer)
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  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
init(opaquePointer: OpaquePointer)
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  • Create a new `PangoLayout` object with attributes initialized to

    default values for a particular PangoContext.

    Declaration

    Swift

    @inlinable
init<ContextT>(context: ContextT) where ContextT : ContextProtocol
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  • Loads data previously created via [methodPango.Layout.serialize].

    For a discussion of the supported format, see that function.

    Note: to verify that the returned layout is identical to the one that was serialized, you can compare bytes to the result of serializing the layout again.

    Declaration

    Swift

    @inlinable
static func deserialize<ContextT, GLibBytesT>(context: ContextT, bytes: GLibBytesT, flags: LayoutDeserializeFlags) throws -> Pango.LayoutRef! where ContextT : ContextProtocol, GLibBytesT : BytesProtocol
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