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.

CSS nodes

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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

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 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 “draw-value”), there is subnode with name value.

gtk_scale_new ()

GtkWidget *
gtk_scale_new (GtkOrientation orientation,
               GtkAdjustment *adjustment);

Creates a new GtkScale.

Since: 3.0

gtk_scale_new_with_range ()

GtkWidget *
gtk_scale_new_with_range (GtkOrientation orientation,
                          gdouble min,
                          gdouble max,
                          gdouble step);

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.

Since: 3.0

gtk_scale_set_digits ()

void
gtk_scale_set_digits (GtkScale *scale,
                      gint digits);

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 “draw-value” is TRUE when the value changes. If you want to enforce rounding the value when “draw-value” is FALSE, you can set “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 the “format-value” signal to format the displayed value yourself.

gtk_scale_set_draw_value ()

void
gtk_scale_set_draw_value (GtkScale *scale,
                          gboolean draw_value);

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

gtk_scale_set_has_origin ()

void
gtk_scale_set_has_origin (GtkScale *scale,
                          gboolean has_origin);

If “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.

Since: 3.4

gtk_scale_set_value_pos ()

void
gtk_scale_set_value_pos (GtkScale *scale,
                         GtkPositionType pos);

Sets the position in which the current value is displayed.

gtk_scale_get_digits ()

gint
gtk_scale_get_digits (GtkScale *scale);

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

gtk_scale_get_draw_value ()

gboolean
gtk_scale_get_draw_value (GtkScale *scale);

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

gtk_scale_get_has_origin ()

gboolean
gtk_scale_get_has_origin (GtkScale *scale);

Returns whether the scale has an origin.

Since: 3.4

gtk_scale_get_value_pos ()

GtkPositionType
gtk_scale_get_value_pos (GtkScale *scale);

Gets the position in which the current value is displayed.

gtk_scale_get_layout ()

PangoLayout *
gtk_scale_get_layout (GtkScale *scale);

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.

Since: 2.4

gtk_scale_get_layout_offsets ()

void
gtk_scale_get_layout_offsets (GtkScale *scale,
                              gint *x,
                              gint *y);

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 “draw-value” property is FALSE, the return values are undefined.

Since: 2.4

gtk_scale_add_mark ()

void
gtk_scale_add_mark (GtkScale *scale,
                    gdouble value,
                    GtkPositionType position,
                    const gchar *markup);

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 NULL, text is shown next to the tick mark.

To remove marks from a scale, use gtk_scale_clear_marks().

Since: 2.16

gtk_scale_clear_marks ()

void
gtk_scale_clear_marks (GtkScale *scale);

Removes any marks that have been added with gtk_scale_add_mark().

Since: 2.16

struct GtkScale

struct GtkScale;

The “digits” property

  “digits”                   int

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

Owner: GtkScale

Flags: Read / Write

Allowed values: [-1,64]

Default value: 1

The “draw-value” property

  “draw-value”               gboolean

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

Owner: GtkScale

Flags: Read / Write

Default value: TRUE

The “has-origin” property

  “has-origin”               gboolean

Whether the scale has an origin.

Owner: GtkScale

Flags: Read / Write

Default value: TRUE

The “value-pos” property

  “value-pos”                GtkPositionType

The position in which the current value is displayed.

Owner: GtkScale

Flags: Read / Write

Default value: GTK_POS_TOP

The “slider-length” style property

  “slider-length”            int

Length of scale's slider.

Owner: GtkScale

Flags: Read

Allowed values: >= 0

Default value: 31

The “value-spacing” style property

  “value-spacing”            int

Space between value text and the slider/trough area.

Owner: GtkScale

Flags: Read

Allowed values: >= 0

Default value: 2

The “format-value” signal

char*
user_function (GtkScale *scale,
               double    value,
               gpointer  user_data)

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 “digits” property.

Here's an example signal handler which displays a value 1.0 as with "-->1.0<--".

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

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