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);


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 {
  GtkRange range;

  gint digits;
  guint draw_value : 1;
  guint value_pos : 2;
} 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 GtkScale: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 GtkScale: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