:right-sidebar: True Scale =================================================================== .. currentmodule:: gi.repository.Gtk .. class:: Scale(**properties: ~typing.Any) :no-contents-entry: Superclasses: :class:`~gi.repository.Gtk.Range`, :class:`~gi.repository.Gtk.Widget`, :class:`~gi.repository.GObject.InitiallyUnowned`, :class:`~gi.repository.GObject.Object` Implemented Interfaces: :class:`~gi.repository.Gtk.Accessible`, :class:`~gi.repository.Gtk.AccessibleRange`, :class:`~gi.repository.Gtk.Buildable`, :class:`~gi.repository.Gtk.ConstraintTarget`, :class:`~gi.repository.Gtk.Orientable` A ``GtkScale`` is a slider control used to select a numeric value. .. image:: https://docs.gtk.org/gtk4/scales.png To use it, you’ll probably want to investigate the methods on its base class, :obj:`~gi.repository.Gtk.Range`\, in addition to the methods for ``GtkScale`` itself. To set the value of a scale, you would normally use :obj:`~gi.repository.Gtk.Range.set_value`\. To detect changes to the value, you would normally use the :obj:`~gi.repository.Gtk.Range.signals.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 ```` element, which can contain multiple ```` elements. The “value” and “position” attributes have the same meaning as :obj:`~gi.repository.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 :kbd:`Ctrl`\. - :kbd:`PgUp` and :kbd:`PgDn` will increment or decrement by page. - :kbd:`Home` and :kbd:`End` will set the minimum or maximum value. CSS nodes -------------------------------------------------------------------------------- .. code-block:: :dedent: 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 :obj:`~gi.repository.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 :obj:`~gi.repository.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 :obj:`~gi.repository.Gtk.Scale.props.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 :const:`~gi.repository.Gtk.AccessibleRole.SLIDER` role. Constructors ------------ .. rst-class:: interim-class .. class:: Scale :no-index: .. classmethod:: new(orientation: ~gi.repository.Gtk.Orientation, adjustment: ~gi.repository.Gtk.Adjustment | None = None) -> ~gi.repository.Gtk.Widget Creates a new ``GtkScale``\. :param orientation: the scale’s orientation. :param adjustment: the :obj:`~gi.repository.Gtk.Adjustment` which sets the range of the scale, or :const:`None` to create a new adjustment. .. classmethod:: new_with_range(orientation: ~gi.repository.Gtk.Orientation, min: float, max: float, step: float) -> ~gi.repository.Gtk.Widget Creates a new scale widget with a range from ``min`` to ``max``\. The returns scale will have the given orientation and will let the user input a number between ``min`` and ``max`` (including ``min`` and ``max``\) with the increment ``step``\. ``step`` must be nonzero; it’s the distance the slider moves when using the arrow keys to adjust the scale value. Note that the way in which the precision is derived works best if ``step`` is a power of ten. If the resulting precision is not suitable for your needs, use :obj:`~gi.repository.Gtk.Scale.set_digits` to correct it. :param orientation: the scale’s orientation. :param min: minimum value :param max: maximum value :param step: step increment (tick size) used with keyboard shortcuts Methods ------- .. rst-class:: interim-class .. class:: Scale :no-index: .. method:: add_mark(value: float, position: ~gi.repository.Gtk.PositionType, markup: str | None = None) -> None 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 :const:`None`, text is shown next to the tick mark. To remove marks from a scale, use :obj:`~gi.repository.Gtk.Scale.clear_marks`\. :param value: the value at which the mark is placed, must be between the lower and upper limits of the scales’ adjustment :param position: where to draw the mark. For a horizontal scale, :const:`~gi.repository.Gtk.PositionType.TOP` and :const:`~gi.repository.Gtk.PositionType.LEFT` are drawn above the scale, anything else below. For a vertical scale, :const:`~gi.repository.Gtk.PositionType.LEFT` and :const:`~gi.repository.Gtk.PositionType.TOP` are drawn to the left of the scale, anything else to the right. :param markup: Text to be shown at the mark, using Pango markup .. method:: clear_marks() -> None Removes any marks that have been added. .. method:: do_get_layout_offsets(self) -> ~typing.Tuple[int, int] .. method:: get_digits() -> int Gets the number of decimal places that are displayed in the value. .. method:: get_draw_value() -> bool Returns whether the current value is displayed as a string next to the slider. .. method:: get_has_origin() -> bool Returns whether the scale has an origin. .. method:: get_layout() -> ~gi.repository.Pango.Layout | None 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. .. method:: get_layout_offsets() -> ~typing.Tuple[int, int] 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 :obj:`~gi.repository.Gtk.Scale.props.draw_value` property is :const:`False`, the return values are undefined. .. method:: get_value_pos() -> ~gi.repository.Gtk.PositionType Gets the position in which the current value is displayed. .. method:: set_digits(digits: int) -> None 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 :obj:`~gi.repository.Gtk.Scale.props.draw_value` is :const:`True` when the value changes. If you want to enforce rounding the value when :obj:`~gi.repository.Gtk.Scale.props.draw_value` is :const:`False`, you can set :obj:`~gi.repository.Gtk.Range.props.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 :obj:`~gi.repository.Gtk.Scale.set_format_value_func` to format the displayed value yourself. :param digits: the number of decimal places to display, e.g. use 1 to display 1.0, 2 to display 1.00, etc .. method:: set_draw_value(draw_value: bool) -> None Specifies whether the current value is displayed as a string next to the slider. :param draw_value: :const:`True` to draw the value .. method:: set_format_value_func(func: ~typing.Callable[[~gi.repository.Gtk.Scale, float, ~typing.Any], str] | None = None, user_data: ~typing.Any = None) -> None ``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 :obj:`~gi.repository.None` is passed as ``func``\, the value will be displayed on its own, rounded according to the value of the :obj:`~gi.repository.Gtk.Scale.props.digits` property. :param func: function that formats the value :param user_data: user data to pass to ``func`` .. method:: set_has_origin(has_origin: bool) -> None Sets whether the scale has an origin. If :obj:`~gi.repository.Gtk.Scale.props.has_origin` is set to :const:`True` (the default), the scale will highlight the part of the trough between the origin (bottom or left side) and the current value. :param has_origin: :const:`True` if the scale has an origin .. method:: set_value_pos(pos: ~gi.repository.Gtk.PositionType) -> None Sets the position in which the current value is displayed. :param pos: the position in which the current value is displayed Properties ---------- .. rst-class:: interim-class .. class:: Scale :no-index: .. attribute:: props.digits :type: int The type of the None singleton. .. attribute:: props.draw_value :type: bool The type of the None singleton. .. attribute:: props.has_origin :type: bool The type of the None singleton. .. attribute:: props.value_pos :type: ~gi.repository.Gtk.PositionType The type of the None singleton. Virtual Methods --------------- .. rst-class:: interim-class .. class:: Scale :no-index: .. method:: do_get_layout_offsets() -> ~typing.Tuple[int, int] 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 :obj:`~gi.repository.Gtk.Scale.props.draw_value` property is :const:`False`, the return values are undefined. Fields ------ .. rst-class:: interim-class .. class:: Scale :no-index: .. attribute:: parent_instance