StyleContext

open class StyleContext : GLibObject.Object, StyleContextProtocol

GtkStyleContext is an object that stores styling information affecting a widget defined by GtkWidgetPath.

In order to construct the final style information, GtkStyleContext queries information from all attached GtkStyleProviders. Style providers can be either attached explicitly to the context through gtk_style_context_add_provider(), or to the screen through gtk_style_context_add_provider_for_screen(). The resulting style is a combination of all providers’ information in priority order.

For GTK+ widgets, any GtkStyleContext returned by gtk_widget_get_style_context() will already have a GtkWidgetPath, a GdkScreen and RTL/LTR information set. The style context will also be updated automatically if any of these settings change on the widget.

If you are using the theming layer standalone, you will need to set a widget path and a screen yourself to the created style context through gtk_style_context_set_path() and possibly gtk_style_context_set_screen(). See the “Foreign drawing“ example in gtk3-demo.

Style Classes #

Widgets can add style classes to their context, which can be used to associate different styles by class. The documentation for individual widgets lists which style classes it uses itself, and which style classes may be added by applications to affect their appearance.

GTK+ defines macros for a number of style classes.

Style Regions

Widgets can also add regions with flags to their context. This feature is deprecated and will be removed in a future GTK+ update. Please use style classes instead.

GTK+ defines macros for a number of style regions.

Custom styling in UI libraries and applications

If you are developing a library with custom GtkWidgets that render differently than standard components, you may need to add a GtkStyleProvider yourself with the GTK_STYLE_PROVIDER_PRIORITY_FALLBACK priority, either a GtkCssProvider or a custom object implementing the GtkStyleProvider interface. This way themes may still attempt to style your UI elements in a different way if needed so.

If you are using custom styling on an applications, you probably want then to make your style information prevail to the theme’s, so you must use a GtkStyleProvider with the GTK_STYLE_PROVIDER_PRIORITY_APPLICATION priority, keep in mind that the user settings in XDG_CONFIG_HOME/gtk-3.0/gtk.css will still take precedence over your changes, as it uses the GTK_STYLE_PROVIDER_PRIORITY_USER priority.

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

    Declaration

    Swift

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

    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 StyleContext instance.

    Declaration

    Swift

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

    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 StyleContext 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 StyleContext 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 StyleContext instance.

    Declaration

    Swift

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

    Parameters

    op

    pointer to the underlying object
    Show on GitHub

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

    Declaration

    Swift

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

    Parameters

    op

    pointer to the underlying object
    Show on GitHub

  • Designated initialiser from the underlying C data type. Will retain GtkStyleContext. i.e., ownership is transferred to the StyleContext instance.

    Declaration

    Swift

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

    Parameters

    op

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

    Declaration

    Swift

    @inlinable
public init<T>(styleContext other: T) where T : StyleContextProtocol

    Parameters

    other

    an instance of a related type that implements StyleContextProtocol
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  • Unsafe typed initialiser. Do not use unless you know the underlying data type the pointer points to conforms to StyleContextProtocol.

    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 StyleContextProtocol.

    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 StyleContextProtocol.

    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 StyleContextProtocol.

    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 StyleContextProtocol.

    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 StyleContextProtocol.

    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 StyleContextProtocol.

    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 StyleContextProtocol.

    Declaration

    Swift

    @inlinable
override public init(retainingOpaquePointer p: OpaquePointer)

    Parameters

    p

    opaque pointer to the underlying object
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  • Creates a standalone GtkStyleContext, this style context won’t be attached to any widget, so you may want to call gtk_style_context_set_path() yourself.

    This function is only useful when using the theming layer separated from GTK+, if you are using GtkStyleContext to theme GtkWidgets, use gtk_widget_get_style_context() in order to get a style context ready to theme the widget.

    Declaration

    Swift

    @inlinable
public init()
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