Struct gtk4::LevelBar

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-width: 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 <offsets> element, which can contain any number of <offset> 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.

Properties

inverted

Whether the GtkLeveBar is inverted.

Level bars normally grow from top to bottom or left to right. Inverted level bars grow in the opposite direction.

Readable | Writeable

max-value

Determines the maximum value of the interval that can be displayed by the bar.

Readable | Writeable

min-value

Determines the minimum value of the interval that can be displayed by the bar.

Readable | Writeable

mode

Determines the way LevelBar interprets the value properties to draw the level fill area.

Specifically, when the value is LevelBarMode::Continuous, LevelBar will draw a single block representing the current value in that area; when the value is LevelBarMode::Discrete, the widget will draw a succession of separate blocks filling the draw area, with the number of blocks being equal to the units separating the integral roundings of min-value and max-value.

Readable | Writeable

value

Determines the currently filled value of the level bar.

Readable | Writeable

Widget

can-focus

Whether the widget or any of its descendents can accept the input focus.

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable

can-target

Whether the widget can receive pointer events.

Readable | Writeable

css-classes

A list of css classes applied to this widget.

Readable | Writeable

css-name

The name of this widget in the CSS tree.

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable | Construct Only

cursor

The cursor used by @widget.

Readable | Writeable

focus-on-click

Whether the widget should grab focus when it is clicked with the mouse.

This property is only relevant for widgets that can take focus.

Readable | Writeable

focusable

Whether this widget itself will accept the input focus.

Readable | Writeable

halign

How to distribute horizontal space if widget gets extra space.

Readable | Writeable

has-default

Whether the widget is the default widget.

Readable

has-focus

Whether the widget has the input focus.

Readable

has-tooltip

Enables or disables the emission of the ::query-tooltip signal on @widget.

A value of true indicates that @widget can have a tooltip, in this case the widget will be queried using query-tooltip to determine whether it will provide a tooltip or not.

Readable | Writeable

height-request

Override for height request of the widget.

If this is -1, the natural request will be used.

Readable | Writeable

hexpand

Whether to expand horizontally.

Readable | Writeable

hexpand-set

Whether to use the hexpand property.

Readable | Writeable

layout-manager

The LayoutManager instance to use to compute the preferred size of the widget, and allocate its children.

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable

margin-bottom

Margin on bottom side of widget.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

margin-end

Margin on end of widget, horizontally.

This property supports left-to-right and right-to-left text directions.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

margin-start

Margin on start of widget, horizontally.

This property supports left-to-right and right-to-left text directions.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

margin-top

Margin on top side of widget.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

name

The name of the widget.

Readable | Writeable

opacity

The requested opacity of the widget.

Readable | Writeable

overflow

How content outside the widget’s content area is treated.

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable

parent

The parent widget of this widget.

Readable

receives-default

Whether the widget will receive the default action when it is focused.

Readable | Writeable

root

The Root widget of the widget tree containing this widget.

This will be None if the widget is not contained in a root widget.

Readable

scale-factor

The scale factor of the widget.

Readable

sensitive

Whether the widget responds to input.

Readable | Writeable

tooltip-markup

Sets the text of tooltip to be the given string, which is marked up with Pango markup.

Also see Tooltip::set_markup().

This is a convenience property which will take care of getting the tooltip shown if the given string is not None: has-tooltip will automatically be set to true and there will be taken care of query-tooltip in the default signal handler.

Note that if both tooltip-text and tooltip-markup are set, the last one wins.

Readable | Writeable

tooltip-text

Sets the text of tooltip to be the given string.

Also see Tooltip::set_text().

This is a convenience property which will take care of getting the tooltip shown if the given string is not None: has-tooltip will automatically be set to true and there will be taken care of query-tooltip in the default signal handler.

Note that if both tooltip-text and tooltip-markup are set, the last one wins.

Readable | Writeable

valign

How to distribute vertical space if widget gets extra space.

Readable | Writeable

vexpand

Whether to expand vertically.

Readable | Writeable

vexpand-set

Whether to use the vexpand property.

Readable | Writeable

visible

Whether the widget is visible.

Readable | Writeable

width-request

Override for width request of the widget.

If this is -1, the natural request will be used.

Readable | Writeable

Accessible

accessible-role

The accessible role of the given Accessible implementation.

The accessible role cannot be changed once set.

Readable | Writeable

Orientable

orientation

The orientation of the orientable.

Readable | Writeable

Signals

offset-changed

Emitted when an offset specified on the bar changes value.

This typically is the result of a LevelBar::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.

Detailed

Widget

destroy

Signals that all holders of a reference to the widget should release the reference that they hold.

May result in finalization of the widget if all references are released.

This signal is not suitable for saving widget state.

direction-changed

Emitted when the text direction of a widget changes.

hide

Emitted when @widget is hidden.

keynav-failed

Emitted if keyboard navigation fails.

See WidgetExt::keynav_failed() for details.

map

Emitted when @widget is going to be mapped.

A widget is mapped when the widget is visible (which is controlled with visible) and all its parents up to the toplevel widget are also visible.

The ::map signal can be used to determine whether a widget will be drawn, for instance it can resume an animation that was stopped during the emission of unmap.

mnemonic-activate

Emitted when a widget is activated via a mnemonic.

The default handler for this signal activates @widget if @group_cycling is false, or just makes @widget grab focus if @group_cycling is true.

move-focus

Emitted when the focus is moved.

The ::move-focus signal is a keybinding signal.

The default bindings for this signal are Tab to move forward, and Shift+Tab to move backward.

Action

query-tooltip

Emitted when the widget’s tooltip is about to be shown.

This happens when the has-tooltip property is true and the hover timeout has expired with the cursor hovering “above” @widget; or emitted when @widget got focus in keyboard mode.

Using the given coordinates, the signal handler should determine whether a tooltip should be shown for @widget. If this is the case true should be returned, false otherwise. Note that if @keyboard_mode is true, the values of @x and @y are undefined and should not be used.

The signal handler is free to manipulate @tooltip with the therefore destined function calls.

realize

Emitted when @widget is associated with a gdk::Surface.

This means that WidgetExt::realize() has been called or the widget has been mapped (that is, it is going to be drawn).

show

Emitted when @widget is shown.

state-flags-changed

Emitted when the widget state changes.

See WidgetExt::state_flags().

unmap

Emitted when @widget is going to be unmapped.

A widget is unmapped when either it or any of its parents up to the toplevel widget have been set as hidden.

As ::unmap indicates that a widget will not be shown any longer, it can be used to, for example, stop an animation on the widget.

unrealize

Emitted when the gdk::Surface associated with @widget is destroyed.

This means that WidgetExt::unrealize() has been called or the widget has been unmapped (that is, it is going to be hidden).

Implements

WidgetExt, [trait@glib::ObjectExt], AccessibleExt, BuildableExt, ConstraintTargetExt, AccessibleRangeExt, 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 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.

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 min-value and 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 min-value and 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 HasParamSpec for LevelBar

type ParamSpec = ParamSpecObject

type SetValue = LevelBar

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, LevelBar>

fn param_spec_builder() -> Self::BuilderFn

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) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized + PartialOrd,

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<AccessibleRange> for LevelBar

impl IsA<Buildable> for LevelBar

impl IsA<ConstraintTarget> for LevelBar

impl IsA<Orientable> for LevelBar

impl IsA<Widget> for LevelBar