GtkAdjustment

typedef struct _GtkAdjustment GtkAdjustment;

The GtkAdjustment struct contains the following fields.

gtk_adjustment_new ()

GtkObject*          gtk_adjustment_new                  (gdouble value,
                                                         gdouble lower,
                                                         gdouble upper,
                                                         gdouble step_increment,
                                                         gdouble page_increment,
                                                         gdouble page_size);

Creates a new GtkAdjustment.

gtk_adjustment_get_value ()

gdouble             gtk_adjustment_get_value            (GtkAdjustment *adjustment);

Gets the current value of the adjustment. See gtk_adjustment_set_value().

gtk_adjustment_set_value ()

void                gtk_adjustment_set_value            (GtkAdjustment *adjustment,
                                                         gdouble value);

Sets the GtkAdjustment value. The value is clamped to lie between adjustment->lower and adjustment->upper.

Note that for adjustments which are used in a GtkScrollbar, the effective range of allowed values goes from adjustment->lower to adjustment->upper - adjustment->page_size.

gtk_adjustment_clamp_page ()

void                gtk_adjustment_clamp_page           (GtkAdjustment *adjustment,
                                                         gdouble lower,
                                                         gdouble upper);

Updates the GtkAdjustment value to ensure that the range between lower and upper is in the current page (i.e. between value and value + page_size). If the range is larger than the page size, then only the start of it will be in the current page. A "changed" signal will be emitted if the value is changed.

gtk_adjustment_changed ()

void                gtk_adjustment_changed              (GtkAdjustment *adjustment);

Emits a "changed" signal from the GtkAdjustment. This is typically called by the owner of the GtkAdjustment after it has changed any of the GtkAdjustment fields other than the value.

gtk_adjustment_value_changed ()

void                gtk_adjustment_value_changed        (GtkAdjustment *adjustment);

Emits a "value_changed" signal from the GtkAdjustment. This is typically called by the owner of the GtkAdjustment after it has changed the GtkAdjustment value field.

gtk_adjustment_configure ()

void                gtk_adjustment_configure            (GtkAdjustment *adjustment,
                                                         gdouble value,
                                                         gdouble lower,
                                                         gdouble upper,
                                                         gdouble step_increment,
                                                         gdouble page_increment,
                                                         gdouble page_size);

Sets all properties of the adjustment at once.

Use this function to avoid multiple emissions of the "changed" signal. See gtk_adjustment_set_lower() for an alternative way of compressing multiple emissions of "changed" into one.

Since 2.14

gtk_adjustment_get_lower ()

gdouble             gtk_adjustment_get_lower            (GtkAdjustment *adjustment);

Retrieves the minimum value of the adjustment.

Since 2.14

gtk_adjustment_get_page_increment ()

gdouble             gtk_adjustment_get_page_increment   (GtkAdjustment *adjustment);

Retrieves the page increment of the adjustment.

Since 2.14

gtk_adjustment_get_page_size ()

gdouble             gtk_adjustment_get_page_size        (GtkAdjustment *adjustment);

Retrieves the page size of the adjustment.

Since 2.14

gtk_adjustment_get_step_increment ()

gdouble             gtk_adjustment_get_step_increment   (GtkAdjustment *adjustment);

Retrieves the step increment of the adjustment.

Since 2.14

gtk_adjustment_get_upper ()

gdouble             gtk_adjustment_get_upper            (GtkAdjustment *adjustment);

Retrieves the maximum value of the adjustment.

Since 2.14

gtk_adjustment_set_lower ()

void                gtk_adjustment_set_lower            (GtkAdjustment *adjustment,
                                                         gdouble lower);

Sets the minimum value of the adjustment.

When setting multiple adjustment properties via their individual setters, multiple "changed" signals will be emitted. However, since the emission of the "changed" signal is tied to the emission of the "GObject::notify" signals of the changed properties, it's possible to compress the "changed" signals into one by calling g_object_freeze_notify() and g_object_thaw_notify() around the calls to the individual setters.

Alternatively, using a single g_object_set() for all the properties to change, or using gtk_adjustment_configure() has the same effect of compressing "changed" emissions.

Since 2.14

gtk_adjustment_set_page_increment ()

void                gtk_adjustment_set_page_increment   (GtkAdjustment *adjustment,
                                                         gdouble page_increment);

Sets the page increment of the adjustment.

See gtk_adjustment_set_lower() about how to compress multiple emissions of the "changed" signal when setting multiple adjustment properties.

Since 2.14

gtk_adjustment_set_page_size ()

void                gtk_adjustment_set_page_size        (GtkAdjustment *adjustment,
                                                         gdouble page_size);

Sets the page size of the adjustment.

See gtk_adjustment_set_lower() about how to compress multiple emissions of the "changed" signal when setting multiple adjustment properties.

Since 2.14

gtk_adjustment_set_step_increment ()

void                gtk_adjustment_set_step_increment   (GtkAdjustment *adjustment,
                                                         gdouble step_increment);

Sets the step increment of the adjustment.

See gtk_adjustment_set_lower() about how to compress multiple emissions of the "changed" signal when setting multiple adjustment properties.

Since 2.14

gtk_adjustment_set_upper ()

void                gtk_adjustment_set_upper            (GtkAdjustment *adjustment,
                                                         gdouble upper);

Sets the maximum value of the adjustment.

Note that values will be restricted by upper - page-size if the page-size property is nonzero.

See gtk_adjustment_set_lower() about how to compress multiple emissions of the "changed" signal when setting multiple adjustment properties.

Since 2.14

The "lower" property

  "lower"                    gdouble               : Read / Write

The minimum value of the adjustment.

Default value: 0

Since 2.4

The "page-increment" property

  "page-increment"           gdouble               : Read / Write

The page increment of the adjustment.

Default value: 0

Since 2.4

The "page-size" property

  "page-size"                gdouble               : Read / Write

The page size of the adjustment. Note that the page-size is irrelevant and should be set to zero if the adjustment is used for a simple scalar value, e.g. in a GtkSpinButton.

Default value: 0

Since 2.4

The "step-increment" property

  "step-increment"           gdouble               : Read / Write

The step increment of the adjustment.

Default value: 0

Since 2.4

The "upper" property

  "upper"                    gdouble               : Read / Write

The maximum value of the adjustment. Note that values will be restricted by upper - page-size if the page-size property is nonzero.

Default value: 0

Since 2.4

The "value" property

  "value"                    gdouble               : Read / Write

The value of the adjustment.

Default value: 0

Since 2.4

The "changed" signal

void                user_function                      (GtkAdjustment *adjustment,
                                                        gpointer       user_data)       : Run First / No Recursion

Emitted when one or more of the GtkAdjustment fields have been changed, other than the value field.

The "value-changed" signal

void                user_function                      (GtkAdjustment *adjustment,
                                                        gpointer       user_data)       : Run First / No Recursion

Emitted when the GtkAdjustment value field has been changed.