Layout

open class Layout : GLibObject.Object, LayoutProtocol

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 Layout type acts as a reference-counted owner of an underlying PangoLayout instance. It provides the methods that can operate on this data type through LayoutProtocol conformance. Use Layout as a strong reference or owner of a PangoLayout instance.

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  • Designated initialiser from the underlying `C` data type.

    This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Layout instance.

    Declaration

    Swift

    @inlinable
public init(_ op: UnsafeMutablePointer<PangoLayout>)

    Parameters

    op

    pointer to the underlying object
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  • Designated initialiser from a constant pointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Layout instance.

    Declaration

    Swift

    @inlinable
public init(_ op: UnsafePointer<PangoLayout>)

    Parameters

    op

    pointer to the underlying object
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  • Optional initialiser from a non-mutating gpointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Layout instance.

    Declaration

    Swift

    @inlinable
override public init!(gpointer op: gpointer?)

    Parameters

    op

    gpointer to the underlying object
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  • Optional initialiser from a non-mutating gconstpointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Layout instance.

    Declaration

    Swift

    @inlinable
override public init!(gconstpointer op: gconstpointer?)

    Parameters

    op

    pointer to the underlying object
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  • Optional initialiser from a constant pointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Layout instance.

    Declaration

    Swift

    @inlinable
public init!(_ op: UnsafePointer<PangoLayout>?)

    Parameters

    op

    pointer to the underlying object
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  • Optional initialiser from the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Layout instance.

    Declaration

    Swift

    @inlinable
public init!(_ op: UnsafeMutablePointer<PangoLayout>?)

    Parameters

    op

    pointer to the underlying object
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  • Designated initialiser from the underlying C data type. Will retain PangoLayout. i.e., ownership is transferred to the Layout instance.

    Declaration

    Swift

    @inlinable
public init(retaining op: UnsafeMutablePointer<PangoLayout>)

    Parameters

    op

    pointer to the underlying object
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  • Reference intialiser for a related type that implements LayoutProtocol Will retain PangoLayout.

    Declaration

    Swift

    @inlinable
public init<T>(layout other: T) where T : LayoutProtocol

    Parameters

    other

    an instance of a related type that implements 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
override public init<T>(cPointer p: UnsafeMutablePointer<T>)

    Parameters

    cPointer

    pointer to the underlying object
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  • Unsafe typed, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
override public init<T>(retainingCPointer cPointer: UnsafeMutablePointer<T>)

    Parameters

    cPointer

    pointer to the underlying object
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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
override public init(raw p: UnsafeRawPointer)

    Parameters

    p

    raw pointer to the underlying object
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  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
override public init(retainingRaw 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
public required init(raw p: UnsafeMutableRawPointer)

    Parameters

    p

    mutable raw pointer to the underlying object
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  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
required public init(retainingRaw raw: UnsafeMutableRawPointer)

    Parameters

    raw

    mutable raw pointer to the underlying object
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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
override public init(opaquePointer p: OpaquePointer)

    Parameters

    p

    opaque pointer to the underlying object
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  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to LayoutProtocol.

    Declaration

    Swift

    @inlinable
override public init(retainingOpaquePointer p: OpaquePointer)

    Parameters

    p

    opaque pointer to the underlying object
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  • Create a new PangoLayout object with attributes initialized to default values for a particular PangoContext.

    Declaration

    Swift

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