Struct gtk4::LevelBar

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

LevelBar is a 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 set_value() to set the current value, and 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 set_min_value() and 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 as GtkBuildable

The LevelBar implementation of the Buildable interface supports a custom element, which can contain any number of elements, each of which must have name and value attributes.

CSS nodes

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

LevelBar 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.

Accessibility

LevelBar uses the AccessibleRole::Meter role.

Implements

WidgetExt, glib::ObjectExt, AccessibleExt, BuildableExt, ConstraintTargetExt, OrientableExt, WidgetExtManual, AccessibleExtManual

Implementations

impl LevelBar

pub fn new() -> LevelBar

Creates a new LevelBar.

Returns

a LevelBar.

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

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.

pub fn add_offset_value(&self, name: &str, value: f64)

Adds a new offset marker on @self at the position specified by @value.

When the bar value is in the interval topped by @value (or between @value and property::LevelBar::max-value in case the offset is the last one on the bar) a style class named level-@name will be applied when rendering the level bar fill.

If another offset marker named @name exists, its value will be replaced by @value.

name

the name of the new offset

value

the value for the new offset

pub fn is_inverted(&self) -> bool

Returns whether the levelbar is inverted.

Returns

true if the level bar is inverted

pub fn max_value(&self) -> f64

Returns the max-value of the LevelBar.

Returns

a positive value

pub fn min_value(&self) -> f64

Returns the min-value of the [LevelBar`]crate::LevelBar.

Returns

a positive value

pub fn mode(&self) -> LevelBarMode

Returns the mode of the LevelBar.

Returns

a LevelBarMode

pub fn offset_value(&self, name: Option<&str>) -> Option<f64>

Fetches the value specified for the offset marker @name in @self.

name

the name of an offset in the bar

Returns

true if the specified offset is found

value

location where to store the value

pub fn value(&self) -> f64

Returns the value of the LevelBar.

Returns

a value in the interval between property::LevelBar::min-value[ and property::LevelBar::max-value

pub fn remove_offset_value(&self, name: Option<&str>)

Removes an offset marker from a LevelBar.

The marker must have been previously added with add_offset_value().

name

the name of an offset in the bar

pub fn set_inverted(&self, inverted: bool)

Sets whether the LevelBar is inverted.

inverted

true to invert the level bar

pub fn set_max_value(&self, value: f64)

Sets the max-value of the LevelBar.

You probably want to update preexisting level offsets after calling this function.

value

a positive value

pub fn set_min_value(&self, value: f64)

Sets the min-value of the LevelBar.

You probably want to update preexisting level offsets after calling this function.

value

a positive value

pub fn set_mode(&self, mode: LevelBarMode)

Sets the mode of the LevelBar.

mode

a LevelBarMode

pub fn set_value(&self, value: f64)

Sets the value of the LevelBar.

value

a value in the interval between property::LevelBar::min-value and property::LevelBar::max-value

pub fn connect_offset_changed<F: Fn(&Self, &str) + 'static>( &self, detail: Option<&str>, f: F ) -> SignalHandlerId

Emitted when an offset specified on the bar changes value.

This typically is the result of a add_offset_value() call.

The signal supports detailed connections; you can connect to the detailed signal “changed::x” in order to only receive callbacks when the value of offset “x” changes.

name

the name of the offset that changed value

pub fn connect_inverted_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_max_value_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_min_value_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_mode_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_value_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

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, Self: Sized,

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) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<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 !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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<Accessible> for LevelBar

impl IsA<Buildable> for LevelBar

impl IsA<ConstraintTarget> for LevelBar

impl IsA<Orientable> for LevelBar

impl IsA<Widget> for LevelBar