Trait gtk::prelude::ScaleExt

source · [−]
pub trait ScaleExt: 'static {

Show 17 methods    fn add_mark(&self, value: f64, position: PositionType, markup: Option<&str>);
    fn clear_marks(&self);
    fn digits(&self) -> i32;
    fn draws_value(&self) -> bool;
    fn has_origin(&self) -> bool;
    fn layout(&self) -> Option<Layout>;
    fn layout_offsets(&self) -> (i32, i32);
    fn value_pos(&self) -> PositionType;
    fn set_digits(&self, digits: i32);
    fn set_draw_value(&self, draw_value: bool);
    fn set_has_origin(&self, has_origin: bool);
    fn set_value_pos(&self, pos: PositionType);
    fn connect_format_value<F: Fn(&Self, f64) -> String + 'static>(
        &self, 
        f: F
    ) -> SignalHandlerId;
    fn connect_digits_notify<F: Fn(&Self) + 'static>(
        &self, 
        f: F
    ) -> SignalHandlerId;
    fn connect_draw_value_notify<F: Fn(&Self) + 'static>(
        &self, 
        f: F
    ) -> SignalHandlerId;
    fn connect_has_origin_notify<F: Fn(&Self) + 'static>(
        &self, 
        f: F
    ) -> SignalHandlerId;
    fn connect_value_pos_notify<F: Fn(&Self) + 'static>(
        &self, 
        f: F
    ) -> SignalHandlerId;

}
Expand description

Trait containing all Scale methods.

Implementors

Scale

Required Methods

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 None, text is shown next to the tick mark.

To remove marks from a scale, use clear_marks().

value

the value at which the mark is placed, must be between the lower and upper limits of the scales’ adjustment

position

where to draw the mark. For a horizontal scale, PositionType::Top and PositionType::Left are drawn above the scale, anything else below. For a vertical scale, PositionType::Left and PositionType::Top are drawn to the left of the scale, anything else to the right.

markup

Text to be shown at the mark, using [Pango markup][PangoMarkupFormat], or None

Removes any marks that have been added with add_mark().

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

Returns

the number of decimal places that are displayed

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

Returns

whether the current value is displayed as a string

Returns whether the scale has an origin.

Returns

true if the scale has an origin.

Gets the pango::Layout used to display the scale. The returned object is owned by the scale so does not need to be freed by the caller.

Returns

the pango::Layout for this scale, or None if the property::Scale::draw-value property is false.

Obtains the coordinates where the scale will draw the pango::Layout representing the text in the scale. Remember when using the pango::Layout function you need to convert to and from pixels using PANGO_PIXELS() or PANGO_SCALE.

If the property::Scale::draw-value property is false, the return values are undefined.

Returns
x

location to store X offset of layout, or None

y

location to store Y offset of layout, or None

Gets the position in which the current value is displayed.

Returns

the position in which the current value is displayed

Sets the number of decimal places that are displayed in the value. Also causes the value of the adjustment to be rounded to this number of digits, so the retrieved value matches the displayed one, if property::Scale::draw-value is true when the value changes. If you want to enforce rounding the value when property::Scale::draw-value is false, you can set property::Range::round-digits instead.

Note that rounding to a small number of digits can interfere with the smooth autoscrolling that is built into Scale. As an alternative, you can use the signal::Scale::format-value signal to format the displayed value yourself.

digits

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

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

draw_value

true to draw the value

If property::Scale::has-origin is set to true (the default), the scale will highlight the part of the trough between the origin (bottom or left side) and the current value.

has_origin

true if the scale has an origin

Sets the position in which the current value is displayed.

pos

the position in which the current value is displayed

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.

If no user-provided handlers are installed, the value will be displayed on its own, rounded according to the value of the property::Scale::digits property.

Here’s an example signal handler which displays a value 1.0 as with “–>1.0<–”.

⚠️ The following code is in C ⚠️

static gchar*
format_value_callback (GtkScale *scale,
                       gdouble   value)
{
  return g_strdup_printf ("-->\%0.*g<--",
                          gtk_scale_get_digits (scale), value);
 }
value

the value to format

Returns

allocated string representing value

Implementors