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GTK+ Reference Manual | |
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| Top | Description | Object Hierarchy | Implemented Interfaces | Properties | Style Properties | Signals | ||||
#include <gtk/gtk.h> struct 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); void gtk_scale_add_mark (GtkScale *scale,gdouble value,GtkPositionType position,const gchar *markup); void gtk_scale_clear_marks (GtkScale *scale);
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().
struct GtkScale;
The fields of the GtkScale struct should only be accessed via the accessor functions.
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.
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a GtkScale |
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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.
void gtk_scale_set_value_pos (GtkScale *scale,GtkPositionType pos);
Sets the position in which the current value is displayed.
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a GtkScale |
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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.
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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.
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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.
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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.
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A GtkScale |
Returns : |
the PangoLayout for this scale, or NULL
if the "draw-value" property is FALSE. |
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.
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a GtkScale |
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location to store X offset of layout, or NULL
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location to store Y offset of layout, or NULL
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Since 2.4
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().
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a GtkScale |
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the value at which the mark is placed, must be between the lower and upper limits of the scales' adjustment |
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where to draw the mark. For a horizontal scale, GTK_POS_TOP is drawn above the scale, anything else below. For a vertical scale, GTK_POS_LEFT is drawn to the left of the scale, anything else to the right. |
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Text to be shown at the mark, using Pango markup, or NULL
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Since 2.16
void gtk_scale_clear_marks (GtkScale *scale);
Removes any marks that have been added with gtk_scale_add_mark().
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a GtkScale |
Since 2.16
"digits" property"digits" gint : Read / Write
The number of decimal places that are displayed in the value.
Allowed values: [G_MAXULONG,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 value,
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<--".
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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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the object which received the signal |
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the value to format |
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user data set when the signal handler was connected. |
Returns : |
allocated string representing value
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