ScaleProtocol

public protocol ScaleProtocol : RangeProtocol

A GtkScale is a slider control used to select a numeric value.

An example GtkScale

To use it, you’ll probably want to investigate the methods on its base class, [classGtkRange], in addition to the methods for GtkScale itself. To set the value of a scale, you would normally use [methodGtk.Range.set_value]. To detect changes to the value, you would normally use the [signalGtk.Range::value-changed] signal.

Note that using the same upper and lower bounds for the GtkScale (through the GtkRange methods) will hide the slider itself. This is useful for applications that want to show an undeterminate value on the scale, without changing the layout of the application (such as movie or music players).

GtkScale as GtkBuildable

GtkScale supports a custom <marks> element, which can contain multiple <mark&gt; elements. The “value” and “position” attributes have the same meaning as [methodGtk.Scale.add_mark] parameters of the same name. If the element is not empty, its content is taken as the markup to show at the mark. It can be translated with the usual ”translatable” and “context” attributes.

CSS nodes

scale[.fine-tune][.marks-before][.marks-after]
├── [value][.top][.right][.bottom][.left]
├── marks.top
│   ├── mark
│   ┊    ├── [label]
│   ┊    ╰── indicator
┊   ┊
│   ╰── mark
├── marks.bottom
│   ├── mark
│   ┊    ├── indicator
│   ┊    ╰── [label]
┊   ┊
│   ╰── mark
╰── trough
    ├── [fill]
    ├── [highlight]
    ╰── slider

GtkScale has a main CSS node with name scale and a subnode for its contents, with subnodes named trough and slider.

The main node gets the style class .fine-tune added when the scale is in ‘fine-tuning’ mode.

If the scale has an origin (see [methodGtk.Scale.set_has_origin]), there is a subnode with name highlight below the trough node that is used for rendering the highlighted part of the trough.

If the scale is showing a fill level (see [methodGtk.Range.set_show_fill_level]), there is a subnode with name fill below the trough node that is used for rendering the filled in part of the trough.

If marks are present, there is a marks subnode before or after the trough node, below which each mark gets a node with name mark. The marks nodes get either the .top or .bottom style class.

The mark node has a subnode named indicator. If the mark has text, it also has a subnode named label. When the mark is either above or left of the scale, the label subnode is the first when present. Otherwise, the indicator subnode is the first.

The main CSS node gets the ‘marks-before’ and/or ‘marks-after’ style classes added depending on what marks are present.

If the scale is displaying the value (see [propertyGtk.Scale:draw-value]), there is subnode with name value. This node will get the .top or .bottom style classes similar to the marks node.

Accessibility

GtkScale uses the GTK_ACCESSIBLE_ROLE_SLIDER role.

The ScaleProtocol protocol exposes the methods and properties of an underlying GtkScale instance. The default implementation of these can be found in the protocol extension below. For a concrete class that implements these methods and properties, see Scale. Alternatively, use ScaleRef as a lighweight, unowned reference if you already have an instance you just want to use.

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  • ptr

    Untyped pointer to the underlying GtkScale instance.

    Declaration

    Swift

    var ptr: UnsafeMutableRawPointer! { get }
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  • scale_ptr Default implementation

    Typed pointer to the underlying GtkScale instance.

    Default Implementation

    Return the stored, untyped pointer as a typed pointer to the GtkScale instance.

    Declaration

    Swift

    var scale_ptr: UnsafeMutablePointer<GtkScale>! { get }
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  • Required Initialiser for types conforming to ScaleProtocol

    Declaration

    Swift

    init(raw: UnsafeMutableRawPointer)
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Scale Class

  • Bind a ScalePropertyName source property to a given target object.

    Declaration

    Swift

    @discardableResult
@inlinable
func bind<Q, T>(property source_property: ScalePropertyName, to target: T, _ target_property: Q, flags f: BindingFlags = .default, transformFrom transform_from: @escaping GLibObject.ValueTransformer = { $0.transform(destValue: $1) }, transformTo transform_to: @escaping GLibObject.ValueTransformer = { $0.transform(destValue: $1) }) -> BindingRef! where Q : PropertyNameProtocol, T : ObjectProtocol

    Parameters

    source_property

    the source property to bind
    target

    the target object to bind to
    target_property

    the target property to bind to
    flags

    the flags to pass to the Binding
    transform_from

    ValueTransformer to use for forward transformation
    transform_to

    ValueTransformer to use for backwards transformation

    Return Value

    binding reference or nil in case of an error

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  • get(property:) Extension method

    Get the value of a Scale property

    Declaration

    Swift

    @inlinable
func get(property: ScalePropertyName) -> GLibObject.Value

    Parameters

    property

    the property to get the value for

    Return Value

    the value of the named property

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  • set(property:value:) Extension method

    Set the value of a Scale property. Note that this will only have an effect on properties that are writable and not construct-only!

    Declaration

    Swift

    @inlinable
func set(property: ScalePropertyName, value v: GLibObject.Value)

    Parameters

    property

    the property to get the value for

    Return Value

    the value of the named property

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Scale Class: ScaleProtocol extension (methods and fields)

  • Adds a mark at value.

    A mark is indicated visually by drawing a tick mark next to the scale, and GTK makes it easy for the user to position the scale exactly at the marks value.

    If markup is not nil, text is shown next to the tick mark.

    To remove marks from a scale, use [methodGtk.Scale.clear_marks].

    Declaration

    Swift

    @inlinable
func addMark(value: CDouble, position: GtkPositionType, markup: UnsafePointer<CChar>? = nil)
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  • clearMarks() Extension method

    Removes any marks that have been added.

    Declaration

    Swift

    @inlinable
func clearMarks()
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  • getDigits() Extension method

    Gets the number of decimal places that are displayed in the value.

    Declaration

    Swift

    @inlinable
func getDigits() -> Int
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  • getDrawValue() Extension method

    Returns whether the current value is displayed as a string next to the slider.

    Declaration

    Swift

    @inlinable
func getDrawValue() -> Bool
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  • getHasOrigin() Extension method

    Returns whether the scale has an origin.

    Declaration

    Swift

    @inlinable
func getHasOrigin() -> Bool
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  • getLayout() Extension method

    Gets the PangoLayout used to display the scale.

    The returned object is owned by the scale so does not need to be freed by the caller.

    Declaration

    Swift

    @inlinable
func getLayout() -> Pango.LayoutRef!
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  • getLayoutOffsets(x:y:) Extension method

    Obtains the coordinates where the scale will draw the PangoLayout representing the text in the scale.

    Remember when using the PangoLayout function you need to convert to and from pixels using PANGO_PIXELS() or PANGO_SCALE.

    If the [propertyGtkScale:draw-value] property is false, the return values are undefined.

    Declaration

    Swift

    @inlinable
func getLayoutOffsets(x: UnsafeMutablePointer<gint>! = nil, y: UnsafeMutablePointer<gint>! = nil)
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  • getValuePos() Extension method

    Gets the position in which the current value is displayed.

    Declaration

    Swift

    @inlinable
func getValuePos() -> GtkPositionType
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  • set(digits:) Extension method

    Sets the number of decimal places that are displayed in the value.

    Also causes the value of the adjustment to be rounded to this number of digits, so the retrieved value matches the displayed one, if [propertyGtkScale:draw-value] is true when the value changes. If you want to enforce rounding the value when [propertyGtkScale:draw-value] is false, you can set [propertyGtkRange:round-digits] instead.

    Note that rounding to a small number of digits can interfere with the smooth autoscrolling that is built into GtkScale. As an alternative, you can use [methodGtk.Scale.set_format_value_func] to format the displayed value yourself.

    Declaration

    Swift

    @inlinable
func set(digits: Int)
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  • set(drawValue:) Extension method

    Specifies whether the current value is displayed as a string next to the slider.

    Declaration

    Swift

    @inlinable
func set(drawValue: Bool)
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  • func allows you to change how the scale value is displayed.

    The given function will return an allocated string representing value. That string will then be used to display the scale’s value.

    If NULL is passed as func, the value will be displayed on its own, rounded according to the value of the [propertyGtkScale:digits] property.

    Declaration

    Swift

    @inlinable
func setFormatValueFunc(func: GtkScaleFormatValueFunc? = nil, userData: gpointer! = nil, destroyNotify: GDestroyNotify? = nil)
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  • set(hasOrigin:) Extension method

    Sets whether the scale has an origin.

    If [propertyGtkScale:has-origin] is set to true (the default), the scale will highlight the part of the trough between the origin (bottom or left side) and the current value.

    Declaration

    Swift

    @inlinable
func set(hasOrigin: Bool)
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  • setValue(pos:) Extension method

    Sets the position in which the current value is displayed.

    Declaration

    Swift

    @inlinable
func setValue(pos: GtkPositionType)
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  • digits Extension method

    The number of decimal places that are displayed in the value.

    Declaration

    Swift

    @inlinable
var digits: Int { get nonmutating set }
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  • drawValue Extension method

    Returns whether the current value is displayed as a string next to the slider.

    Declaration

    Swift

    @inlinable
var drawValue: Bool { get nonmutating set }
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  • hasOrigin Extension method

    Returns whether the scale has an origin.

    Declaration

    Swift

    @inlinable
var hasOrigin: Bool { get nonmutating set }
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  • layout Extension method

    Gets the PangoLayout used to display the scale.

    The returned object is owned by the scale so does not need to be freed by the caller.

    Declaration

    Swift

    @inlinable
var layout: Pango.LayoutRef! { get }
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  • valuePos Extension method

    Gets the position in which the current value is displayed.

    Declaration

    Swift

    @inlinable
var valuePos: GtkPositionType { get nonmutating set }
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  • parentInstance Extension method

    Undocumented

    Declaration

    Swift

    @inlinable
var parentInstance: GtkRange { get }
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