Gtk.Scale
Description: Reference for Gtk.Scale

### Class

# GtkScale

#### Description [src]

    class Gtk.Scale : Gtk.Range
      implements Gtk.Accessible, Gtk.AccessibleRange, Gtk.Buildable, Gtk.ConstraintTarget, Gtk.Orientable {
      /* No available fields */
    }

Allows to select a numeric value with a slider control.

To use it, you’ll probably want to investigate the methods on its base class, `GtkRange`, in addition to the methods for `GtkScale` itself. To set the value of a scale, you would normally use `gtk_range_set_value()`. To detect changes to the value, you would normally use the `GtkRange::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\>` elements. The “value” and “position” attributes have the same meaning as `gtk_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.

# Shortcuts and Gestures

`GtkPopoverMenu` supports the following keyboard shortcuts:

- Arrow keys, `+` and `-` will increment or decrement by step, or by page when combined with `Ctrl`.
- `PgUp` and `PgDn` will increment or decrement by page.
- `Home` and `End` will set the minimum or maximum value.

# 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 `gtk_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 `gtk_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 `GtkScale: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.

#### Ancestors

- GtkRange
- GtkWidget
- GInitiallyUnowned
- GObject

#### Implements

- GtkAccessible
- GtkAccessibleRange
- GtkBuildable
- GtkConstraintTarget
- GtkOrientable

#### Constructors

###### gtk_scale_new

Creates a new `GtkScale`.

###### gtk_scale_new_with_range

Creates a new scale widget with a range from `min` to `max`.

#### Instance methods

###### gtk_scale_add_mark

Adds a mark at `value`.

###### gtk_scale_clear_marks

Removes any marks that have been added.

###### gtk_scale_get_digits

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

###### gtk_scale_get_draw_value

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

###### gtk_scale_get_has_origin

Returns whether the scale has an origin.

###### gtk_scale_get_layout

Gets the `PangoLayout` used to display the scale.

###### gtk_scale_get_layout_offsets

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

###### gtk_scale_get_value_pos

Gets the position in which the current value is displayed.

###### gtk_scale_set_digits

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

###### gtk_scale_set_draw_value

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

###### gtk_scale_set_format_value_func

`func` allows you to change how the scale value is displayed.

###### gtk_scale_set_has_origin

Sets whether the scale has an origin.

###### gtk_scale_set_value_pos

Sets the position in which the current value is displayed.

##### Methods inherited from GtkRange (22)

###### gtk_range_get_adjustment

Get the adjustment which is the “model” object for `GtkRange`.

###### gtk_range_get_fill_level

Gets the current position of the fill level indicator.

###### gtk_range_get_flippable

Gets whether the `GtkRange` respects text direction.

###### gtk_range_get_inverted

Gets whether the range is inverted.

###### gtk_range_get_range_rect

This function returns the area that contains the range’s trough, in coordinates relative to `range`‘s origin.

###### gtk_range_get_restrict_to_fill_level

Gets whether the range is restricted to the fill level.

###### gtk_range_get_round_digits

Gets the number of digits to round the value to when it changes.

###### gtk_range_get_show_fill_level

Gets whether the range displays the fill level graphically.

###### gtk_range_get_slider_range

This function returns sliders range along the long dimension, in widget->window coordinates.

###### gtk_range_get_slider_size_fixed

This function is useful mainly for `GtkRange` subclasses.

###### gtk_range_get_value

Gets the current value of the range.

###### gtk_range_set_adjustment

Sets the adjustment to be used as the “model” object for the `GtkRange`.

###### gtk_range_set_fill_level

Set the new position of the fill level indicator.

###### gtk_range_set_flippable

Sets whether the `GtkRange` respects text direction.

###### gtk_range_set_increments

Sets the step and page sizes for the range.

###### gtk_range_set_inverted

Sets whether to invert the range.

###### gtk_range_set_range

Sets the allowable values in the `GtkRange`.

###### gtk_range_set_restrict_to_fill_level

Sets whether the slider is restricted to the fill level.

###### gtk_range_set_round_digits

Sets the number of digits to round the value to when it changes.

###### gtk_range_set_show_fill_level

Sets whether a graphical fill level is show on the trough.

###### gtk_range_set_slider_size_fixed

Sets whether the range’s slider has a fixed size, or a size that depends on its adjustment’s page size.

###### gtk_range_set_value

Sets the current value of the range.

##### Methods inherited from GtkWidget (164)

Please see GtkWidget for a full list of methods.

##### Methods inherited from GObject (43)

Please see GObject for a full list of methods.

##### Methods inherited from GtkAccessible (20)

###### gtk_accessible_announce

Requests the user’s screen reader to announce the given message.

since: 4.14

###### gtk_accessible_get_accessible_parent

Retrieves the accessible parent for an accessible object.

since: 4.10

###### gtk_accessible_get_accessible_role

Retrieves the accessible role of an accessible object.

###### gtk_accessible_get_at_context

Retrieves the implementation for the given accessible object.

since: 4.10

###### gtk_accessible_get_bounds

Queries the coordinates and dimensions of this accessible.

since: 4.10

###### gtk_accessible_get_first_accessible_child

Retrieves the first accessible child of an accessible object.

since: 4.10

###### gtk_accessible_get_next_accessible_sibling

Retrieves the next accessible sibling of an accessible object.

since: 4.10

###### gtk_accessible_get_platform_state

Queries a platform state, such as focus.

since: 4.10

###### gtk_accessible_reset_property

Resets the accessible property to its default value.

###### gtk_accessible_reset_relation

Resets the accessible relation to its default value.

###### gtk_accessible_reset_state

Resets the accessible state to its default value.

###### gtk_accessible_set_accessible_parent

Sets the parent and sibling of an accessible object.

since: 4.10

###### gtk_accessible_update_next_accessible_sibling

Updates the next accessible sibling.

since: 4.10

###### gtk_accessible_update_platform_state

Informs ATs that the platform state has changed.

since: 4.18

###### gtk_accessible_update_property

Updates a list of accessible properties.

###### gtk_accessible_update_property_value

Updates an array of accessible properties.

###### gtk_accessible_update_relation

Updates a list of accessible relations.

###### gtk_accessible_update_relation_value

Updates an array of accessible relations.

###### gtk_accessible_update_state

Updates a list of accessible states.

###### gtk_accessible_update_state_value

Updates an array of accessible states.

##### Methods inherited from GtkBuildable (1)

###### gtk_buildable_get_buildable_id

Gets the ID of the `buildable` object.

##### Methods inherited from GtkOrientable (2)

###### gtk_orientable_get_orientation

Retrieves the orientation of the `orientable`.

###### gtk_orientable_set_orientation

Sets the orientation of the `orientable`.

#### Properties

###### Gtk.Scale:digits

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

###### Gtk.Scale:draw-value

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

###### Gtk.Scale:has-origin

Whether the scale has an origin.

###### Gtk.Scale:value-pos

The position in which the current value is displayed.

##### Properties inherited from GtkRange (6)

###### Gtk.Range:adjustment

The adjustment that is controlled by the range.

###### Gtk.Range:fill-level

The fill level (e.g. prebuffering of a network stream).

###### Gtk.Range:inverted

If `TRUE`, the direction in which the slider moves is inverted.

###### Gtk.Range:restrict-to-fill-level

Controls whether slider movement is restricted to an upper boundary set by the fill level.

###### Gtk.Range:round-digits

The number of digits to round the value to when it changes.

###### Gtk.Range:show-fill-level

Controls whether fill level indicator graphics are displayed on the trough.

##### Properties inherited from GtkWidget (35)

###### Gtk.Widget:can-focus

Whether the widget or any of its descendents can accept the input focus.

###### Gtk.Widget:can-target

Whether the widget can receive pointer events.

###### Gtk.Widget:css-classes

A list of css classes applied to this widget.

###### Gtk.Widget:css-name

The name of this widget in the CSS tree.

###### Gtk.Widget:cursor

The cursor used by `widget`.

###### Gtk.Widget:focus-on-click

Whether the widget should grab focus when it is clicked with the mouse.

###### Gtk.Widget:focusable

Whether this widget itself will accept the input focus.

###### Gtk.Widget:halign

How to distribute horizontal space if widget gets extra space.

###### Gtk.Widget:has-default

Whether the widget is the default widget.

###### Gtk.Widget:has-focus

Whether the widget has the input focus.

###### Gtk.Widget:has-tooltip

Enables or disables the emission of the `GtkWidget::query-tooltip` signal on `widget`.

###### Gtk.Widget:height-request

Overrides for height request of the widget.

###### Gtk.Widget:hexpand

Whether to expand horizontally.

###### Gtk.Widget:hexpand-set

Whether to use the `hexpand` property.

###### Gtk.Widget:layout-manager

The `GtkLayoutManager` instance to use to compute the preferred size of the widget, and allocate its children.

###### Gtk.Widget:limit-events

Makes this widget act like a modal dialog, with respect to event delivery.

since: 4.18

###### Gtk.Widget:margin-bottom

Margin on bottom side of widget.

###### Gtk.Widget:margin-end

Margin on end of widget, horizontally.

###### Gtk.Widget:margin-start

Margin on start of widget, horizontally.

###### Gtk.Widget:margin-top

Margin on top side of widget.

###### Gtk.Widget:name

The name of the widget.

###### Gtk.Widget:opacity

The requested opacity of the widget.

###### Gtk.Widget:overflow

How content outside the widget’s content area is treated.

###### Gtk.Widget:parent

The parent widget of this widget.

###### Gtk.Widget:receives-default

Whether the widget will receive the default action when it is focused.

###### Gtk.Widget:root

The `GtkRoot` widget of the widget tree containing this widget.

###### Gtk.Widget:scale-factor

The scale factor of the widget.

###### Gtk.Widget:sensitive

Whether the widget responds to input.

###### Gtk.Widget:tooltip-markup

Sets the text of tooltip to be the given string, which is marked up with Pango markup.

###### Gtk.Widget:tooltip-text

Sets the text of tooltip to be the given string.

###### Gtk.Widget:valign

How to distribute vertical space if widget gets extra space.

###### Gtk.Widget:vexpand

Whether to expand vertically.

###### Gtk.Widget:vexpand-set

Whether to use the `vexpand` property.

###### Gtk.Widget:visible

Whether the widget is visible.

###### Gtk.Widget:width-request

Overrides for width request of the widget.

##### Properties inherited from GtkAccessible (1)

###### GtkAccessible:accessible-role

The accessible role of the given `GtkAccessible` implementation.

##### Properties inherited from GtkOrientable (1)

###### GtkOrientable:orientation

The orientation of the orientable.

#### Signals

##### Signals inherited from GtkRange (4)

###### GtkRange::adjust-bounds

Emitted before clamping a value, to give the application a chance to adjust the bounds.

###### GtkRange::change-value

Emitted when a scroll action is performed on a range.

###### GtkRange::move-slider

Virtual function that moves the slider.

###### GtkRange::value-changed

Emitted when the range value changes.

##### Signals inherited from GtkWidget (13)

###### GtkWidget::destroy

Signals that all holders of a reference to the widget should release the reference that they hold.

###### GtkWidget::direction-changed

Emitted when the text direction of a widget changes.

###### GtkWidget::hide

Emitted when `widget` is hidden.

###### GtkWidget::keynav-failed

Emitted if keyboard navigation fails.

###### GtkWidget::map

Emitted when `widget` is going to be mapped.

###### GtkWidget::mnemonic-activate

Emitted when a widget is activated via a mnemonic.

###### GtkWidget::move-focus

Emitted when the focus is moved.

###### GtkWidget::query-tooltip

Emitted when the widget’s tooltip is about to be shown.

###### GtkWidget::realize

Emitted when `widget` is associated with a `GdkSurface`.

###### GtkWidget::show

Emitted when `widget` is shown.

###### GtkWidget::state-flags-changed

Emitted when the widget state changes.

###### GtkWidget::unmap

Emitted when `widget` is going to be unmapped.

###### GtkWidget::unrealize

Emitted when the `GdkSurface` associated with `widget` is destroyed.

##### Signals inherited from GObject (1)

###### GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

#### Class structure

    struct GtkScaleClass {
      GtkRangeClass parent_class;
      void (* get_layout_offsets) (
        GtkScale* scale,
        int* x,
        int* y
      );

    }

No description available.

###### Class members

`parent_class: GtkRangeClass`

  No description available.

`get_layout_offsets: void (* get_layout_offsets) ( GtkScale* scale, int* x, int* y )`

  No description available.

#### Virtual methods

###### Gtk.ScaleClass.get_layout_offsets

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