Struct gtk::LevelBar

#[repr(transparent)]
pub struct LevelBar { /* private fields */ }

The LevelBar is a bar widget that can be used as a level indicator. Typical use cases are displaying the strength of a password, or showing the charge level of a battery.

Use LevelBarExt::set_value() to set the current value, and LevelBarExt::add_offset_value() to set the value offsets at which the bar will be considered in a different state. GTK will add a few offsets by default on the level bar: LEVEL_BAR_OFFSET_LOW, LEVEL_BAR_OFFSET_HIGH and LEVEL_BAR_OFFSET_FULL, with values 0.25, 0.75 and 1.0 respectively.

Note that it is your responsibility to update preexisting offsets when changing the minimum or maximum value. GTK+ will simply clamp them to the new range.

Adding a custom offset on the bar

⚠️ The following code is in C ⚠️

static GtkWidget *
create_level_bar (void)
{
  GtkWidget *widget;
  GtkLevelBar *bar;

  widget = gtk_level_bar_new ();
  bar = GTK_LEVEL_BAR (widget);

  // This changes the value of the default low offset

  gtk_level_bar_add_offset_value (bar,
                                  GTK_LEVEL_BAR_OFFSET_LOW,
                                  0.10);

  // This adds a new offset to the bar; the application will
  // be able to change its color CSS like this:
  //
  // levelbar block.my-offset {
  //   background-color: magenta;
  //   border-style: solid;
  //   border-color: black;
  //   border-style: 1px;
  // }

  gtk_level_bar_add_offset_value (bar, "my-offset", 0.60);

  return widget;
}

The default interval of values is between zero and one, but it’s possible to modify the interval using LevelBarExt::set_min_value() and LevelBarExt::set_max_value(). The value will be always drawn in proportion to the admissible interval, i.e. a value of 15 with a specified interval between 10 and 20 is equivalent to a value of 0.5 with an interval between 0 and 1. When LevelBarMode::Discrete is used, the bar level is rendered as a finite number of separated blocks instead of a single one. The number of blocks that will be rendered is equal to the number of units specified by the admissible interval.

For instance, to build a bar rendered with five blocks, it’s sufficient to set the minimum value to 0 and the maximum value to 5 after changing the indicator mode to discrete.

GtkLevelBar was introduced in GTK+ 3.6.

GtkLevelBar as GtkBuildable

The GtkLevelBar implementation of the GtkBuildable interface supports a custom <offsets> element, which can contain any number of <offset> elements, each of which must have “name” and “value” attributes.

CSS nodes

⚠️ The following code is in plain ⚠️

levelbar[.discrete]
╰── trough
    ├── block.filled.level-name
    ┊
    ├── block.empty
    ┊

GtkLevelBar has a main CSS node with name levelbar and one of the style classes .discrete or .continuous and a subnode with name trough. Below the trough node are a number of nodes with name block and style class .filled or .empty. In continuous mode, there is exactly one node of each, in discrete mode, the number of filled and unfilled nodes corresponds to blocks that are drawn. The block.filled nodes also get a style class .level-name corresponding to the level for the current value.

In horizontal orientation, the nodes are always arranged from left to right, regardless of text direction.

Implements

LevelBarExt, WidgetExt, glib::ObjectExt, BuildableExt, OrientableExt, WidgetExtManual, BuildableExtManual

Implementations

impl LevelBar

pub const NONE: Option<&'static LevelBar> = None

pub fn new() -> LevelBar

Creates a new LevelBar.

Returns

a LevelBar.

pub fn for_interval(min_value: f64, max_value: f64) -> LevelBar

Utility constructor that creates a new LevelBar for the specified interval.

min_value

a positive value

max_value

a positive value

Returns

a LevelBar

pub fn builder() -> LevelBarBuilder

Creates a new builder-pattern struct instance to construct LevelBar objects.

This method returns an instance of LevelBarBuilder which can be used to create LevelBar objects.

Trait Implementations

impl Clone for LevelBar

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LevelBar

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LevelBar

fn default() -> Self

Returns the “default value” for a type.

impl Display for LevelBar

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for LevelBar

fn hash<H>(&self, state: &mut H) where
    H: Hasher, 

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Ord for LevelBar

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl ParentClassIs for LevelBar

type Parent = Widget

impl<OT: ObjectType> PartialEq<OT> for LevelBar

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<OT: ObjectType> PartialOrd<OT> for LevelBar

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for LevelBar

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for LevelBar

impl IsA<Buildable> for LevelBar

impl IsA<Orientable> for LevelBar

impl IsA<Widget> for LevelBar