GtkScale

GtkScale — Base class for GtkHScale and GtkVScale

Synopsis


#include <gtk/gtk.h>


                    GtkScale;
void                gtk_scale_set_digits                (GtkScale *scale,
                                                         gint digits);
void                gtk_scale_set_draw_value            (GtkScale *scale,
                                                         gboolean draw_value);
void                gtk_scale_set_value_pos             (GtkScale *scale,
                                                         GtkPositionType pos);
gint                gtk_scale_get_digits                (GtkScale *scale);
gboolean            gtk_scale_get_draw_value            (GtkScale *scale);
GtkPositionType     gtk_scale_get_value_pos             (GtkScale *scale);
PangoLayout*        gtk_scale_get_layout                (GtkScale *scale);
void                gtk_scale_get_layout_offsets        (GtkScale *scale,
                                                         gint *x,
                                                         gint *y);


Object Hierarchy


  GObject
   +----GInitiallyUnowned
         +----GtkObject
               +----GtkWidget
                     +----GtkRange
                           +----GtkScale
                                 +----GtkHScale
                                 +----GtkVScale

Implemented Interfaces

GtkScale implements AtkImplementorIface and GtkBuildable.

Properties


  "digits"                   gint                  : Read / Write
  "draw-value"               gboolean              : Read / Write
  "value-pos"                GtkPositionType       : Read / Write

Style Properties


  "slider-length"            gint                  : Read
  "value-spacing"            gint                  : Read

Signals


  "format-value"                                   : Run Last

Description

A GtkScale 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, 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 "value_changed" signal.

The GtkScale widget is an abstract class, used only for deriving the subclasses GtkHScale and GtkVScale. To create a scale widget, call gtk_hscale_new_with_range() or gtk_vscale_new_with_range().

Details

GtkScale

typedef struct _GtkScale GtkScale;

The GtkScale struct contains the following fields. (These fields should be considered read-only. They should never be set by an application.)

guint draw_value; non-zero if the scale's current value is displayed next to the slider.
guint value_pos; the position in which the textual value is displayed, selected from GtkPositionType.


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 off to this number of digits, so the retrieved value matches the value the user saw.

scale :

a GtkScale.

digits :

the number of decimal places to display, e.g. use 1 to display 1.0, 2 to display 1.00 etc.

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.

scale :

a GtkScale.

draw_value :

a boolean.

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.

scale :

a GtkScale.

pos :

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.

scale :

a GtkScale.

Returns :

the number of decimal places that are displayed.

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.

scale :

a GtkScale.

Returns :

whether the current value is displayed as a string.

gtk_scale_get_value_pos ()

GtkPositionType     gtk_scale_get_value_pos             (GtkScale *scale);

Gets the position in which the current value is displayed.

scale :

a GtkScale.

Returns :

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.

scale :

A GtkScale

Returns :

the PangoLayout for this scale, or NULL if the "draw-value" property is FALSE.

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.

scale :

a GtkScale

x :

location to store X offset of layout, or NULL

y :

location to store Y offset of layout, or NULL

Since 2.4

Property Details

The "digits" property

  "digits"                   gint                  : Read / Write

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

Allowed values: [-1,64]

Default value: 1


The "draw-value" property

  "draw-value"               gboolean              : Read / Write

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

Default value: TRUE


The "value-pos" property

  "value-pos"                GtkPositionType       : Read / Write

The position in which the current value is displayed.

Default value: GTK_POS_TOP

Style Property Details

The "slider-length" style property

  "slider-length"            gint                  : Read

Length of scale's slider.

Allowed values: >= 0

Default value: 31


The "value-spacing" style property

  "value-spacing"            gint                  : Read

Space between value text and the slider/trough area.

Allowed values: >= 0

Default value: 2

Signal Details

The "format-value" signal

gchar*              user_function                      (GtkScale *scale,
                                                        gdouble   arg1,
                                                        gpointer  user_data)      : Run Last

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. 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);
}

scale :

the object which received the signal.

arg1 :

user_data :

user data set when the signal handler was connected.

Returns :

allocated string representing value