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GTK+ Reference Manual | |
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#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);
GObject +----GInitiallyUnowned +----GtkObject +----GtkWidget +----GtkRange +----GtkScale +----GtkHScale +----GtkVScale
"digits" gint : Read / Write "draw-value" gboolean : Read / Write "value-pos" GtkPositionType : Read / Write
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().
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. |
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. |
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. |
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. |
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. |
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. |
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. |
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.
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Since 2.4
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
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y : |
location to store Y offset of layout, or NULL
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Since 2.4
"digits" property"digits" gint : Read / Write
The number of decimal places that are displayed in the value.
Allowed values: [-1,64]
Default value: 1
"draw-value" property"draw-value" gboolean : Read / Write
Whether the current value is displayed as a string next to the slider.
Default value: TRUE
"value-pos" property"value-pos" GtkPositionType : Read / Write
The position in which the current value is displayed.
Default value: GTK_POS_TOP
"slider-length" style property"slider-length" gint : Read
Length of scale's slider.
Allowed values: >= 0
Default value: 31
"value-spacing" style property"value-spacing" gint : Read
Space between value text and the slider/trough area.
Allowed values: >= 0
Default value: 2
"format-value" signalgchar* 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 : |
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user_data : |
user data set when the signal handler was connected. |
| Returns : | allocated string representing value
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