Gtk.Scale

g Atk.ImplementorIface Atk.ImplementorIface Gtk.Widget Gtk.Widget Atk.ImplementorIface->Gtk.Widget GObject.GInterface GObject.GInterface GObject.GInterface->Atk.ImplementorIface Gtk.Buildable Gtk.Buildable GObject.GInterface->Gtk.Buildable Gtk.Orientable Gtk.Orientable GObject.GInterface->Gtk.Orientable GObject.InitiallyUnowned GObject.InitiallyUnowned GObject.InitiallyUnowned->Gtk.Widget GObject.Object GObject.Object GObject.Object->GObject.InitiallyUnowned Gtk.Buildable->Gtk.Widget Gtk.Range Gtk.Range Gtk.Orientable->Gtk.Range Gtk.Scale Gtk.Scale Gtk.Range->Gtk.Scale Gtk.Widget->Gtk.Range

Example

../_images/Scale.png
Subclasses:Gtk.HScale, Gtk.VScale

Methods

Inherited:Gtk.Range (28), Gtk.Widget (278), GObject.Object (37), Gtk.Buildable (10), Gtk.Orientable (2)
Structs:Gtk.WidgetClass (12), GObject.ObjectClass (5)
class new (orientation, adjustment)
class new_with_range (orientation, min, max, step)
  add_mark (value, position, markup)
  clear_marks ()
  get_digits ()
  get_draw_value ()
  get_has_origin ()
  get_layout ()
  get_layout_offsets ()
  get_value_pos ()
  set_digits (digits)
  set_draw_value (draw_value)
  set_has_origin (has_origin)
  set_value_pos (pos)

Properties

Inherited:Gtk.Range (8), Gtk.Widget (39), Gtk.Orientable (1)
Name Type Flags Short Description
digits int r/w/en The number of decimal places that are displayed in the value
draw-value bool r/w/en Whether the current value is displayed as a string next to the slider
has-origin bool r/w/en Whether the scale has an origin
value-pos Gtk.PositionType r/w/en The position in which the current value is displayed

Style Properties

Inherited:Gtk.Range (8), Gtk.Widget (17)
Name Type Default Flags Short Description
slider-length int 31 d/r Length of scale’s slider deprecated
value-spacing int 2 d/r Space between value text and the slider/trough area deprecated

Signals

Inherited:Gtk.Range (4), Gtk.Widget (69), GObject.Object (1)
Name Short Description
format-value Signal which allows you to change how the scale value is displayed.

Fields

Inherited:Gtk.Range (4), Gtk.Widget (69), GObject.Object (1)
Name Type Access Description
range Gtk.Range r  

Class Details

class Gtk.Scale(**kwargs)
Bases:Gtk.Range
Abstract:No
Structure:Gtk.ScaleClass

A Gtk.Scale is a slider control used to select a numeric value. To use it, you’ll probably want to investigate the methods on its base class, Gtk.Range, in addition to the methods for Gtk.Scale 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 Gtk.Range ::value-changed signal.

Note that using the same upper and lower bounds for the Gtk.Scale (through the Gtk.Range 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).

Gtk.Scale as Gtk.Buildable

Gtk.Scale 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.

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

Gtk.Scale 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 contents 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 Gtk.Scale :draw-value), there is subnode with name value.

classmethod new(orientation, adjustment)[source]
Parameters:
Returns:

a new Gtk.Scale

Return type:

Gtk.Widget

Creates a new Gtk.Scale.

New in version 3.0.

classmethod new_with_range(orientation, min, max, step)[source]
Parameters:
  • orientation (Gtk.Orientation) – the scale’s orientation.
  • min (float) – minimum value
  • max (float) – maximum value
  • step (float) – step increment (tick size) used with keyboard shortcuts
Returns:

a new Gtk.Scale

Return type:

Gtk.Widget

Creates a new scale widget with the given orientation that lets 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 Gtk.Scale.set_digits() to correct it.

New in version 3.0.

add_mark(value, position, markup)[source]
Parameters:

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 None, text is shown next to the tick mark.

To remove marks from a scale, use Gtk.Scale.clear_marks().

New in version 2.16.

clear_marks()[source]

Removes any marks that have been added with Gtk.Scale.add_mark().

New in version 2.16.

get_digits()[source]
Returns:the number of decimal places that are displayed
Return type:int

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

get_draw_value()[source]
Returns:whether the current value is displayed as a string
Return type:bool

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

get_has_origin()[source]
Returns:True if the scale has an origin.
Return type:bool

Returns whether the scale has an origin.

New in version 3.4.

get_layout()[source]
Returns:the Pango.Layout for this scale, or None if the Gtk.Scale :draw-value property is False.
Return type:Pango.Layout or None

Gets the Pango.Layout used to display the scale. The returned object is owned by the scale so does not need to be freed by the caller.

New in version 2.4.

get_layout_offsets()[source]
Returns:
x:location to store X offset of layout, or None
y:location to store Y offset of layout, or None
Return type:(x: int, y: int)

Obtains the coordinates where the scale will draw the Pango.Layout representing the text in the scale. Remember when using the Pango.Layout function you need to convert to and from pixels using PANGO_PIXELS() or Pango.SCALE.

If the Gtk.Scale :draw-value property is False, the return values are undefined.

New in version 2.4.

get_value_pos()[source]
Returns:the position in which the current value is displayed
Return type:Gtk.PositionType

Gets the position in which the current value is displayed.

set_digits(digits)[source]
Parameters:digits (int) – the number of decimal places to display, e.g. use 1 to display 1.0, 2 to display 1.00, etc

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 Gtk.Scale :draw-value is True when the value changes. If you want to enforce rounding the value when Gtk.Scale :draw-value is False, you can set Gtk.Range :round-digits instead.

Note that rounding to a small number of digits can interfere with the smooth autoscrolling that is built into Gtk.Scale. As an alternative, you can use the Gtk.Scale ::format-value signal to format the displayed value yourself.

set_draw_value(draw_value)[source]
Parameters:draw_value (bool) – True to draw the value

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

set_has_origin(has_origin)[source]
Parameters:has_origin (bool) – True if the scale has an origin

If Gtk.Scale :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.

New in version 3.4.

set_value_pos(pos)[source]
Parameters:pos (Gtk.PositionType) – the position in which the current value is displayed

Sets the position in which the current value is displayed.

do_draw_value() virtual
do_format_value(value) virtual
Parameters:value (float) –
Return type:str
do_get_layout_offsets() virtual
Returns:
x:location to store X offset of layout, or None
y:location to store Y offset of layout, or None
Return type:(x: int, y: int)

Obtains the coordinates where the scale will draw the Pango.Layout representing the text in the scale. Remember when using the Pango.Layout function you need to convert to and from pixels using PANGO_PIXELS() or Pango.SCALE.

If the Gtk.Scale :draw-value property is False, the return values are undefined.

New in version 2.4.

Signal Details

Gtk.Scale.signals.format_value(scale, value)
Signal Name:

format-value

Flags:

RUN_LAST

Parameters:
  • scale (Gtk.Scale) – The object which received the signal
  • value (float) – the value to format
Returns:

allocated string representing value

Return type:

str

Signal which allows you to change how the scale value is displayed. Connect a signal handler which returns an allocated string representing value. That string will then be used to display the scale’s value.

If no user-provided handlers are installed, the value will be displayed on its own, rounded according to the value of the Gtk.Scale :digits property.

Here’s an example signal handler which displays a value 1.0 as with “–>1.0<–”.

static gchar*
format_value_callback (GtkScale *scale,
                       gdouble   value)
{
  return g_strdup_printf ("-->\%0.*g<--",
                          gtk_scale_get_digits (scale), value);
 }

Property Details

Gtk.Scale.props.digits
Name:digits
Type:int
Default Value:1
Flags:READABLE, WRITABLE, EXPLICIT_NOTIFY

The number of decimal places that are displayed in the value

Gtk.Scale.props.draw_value
Name:draw-value
Type:bool
Default Value:True
Flags:READABLE, WRITABLE, EXPLICIT_NOTIFY

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

Gtk.Scale.props.has_origin
Name:has-origin
Type:bool
Default Value:True
Flags:READABLE, WRITABLE, EXPLICIT_NOTIFY

Whether the scale has an origin

Gtk.Scale.props.value_pos
Name:value-pos
Type:Gtk.PositionType
Default Value:Gtk.PositionType.TOP
Flags:READABLE, WRITABLE, EXPLICIT_NOTIFY

The position in which the current value is displayed