class Gtk::LevelBar

• Gtk::LevelBar
• Gtk::Widget
• GObject::InitiallyUnowned
• GObject::Object
• Reference
• Object

Overview

Gtk::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 Gtk::LevelBar#value= to set the current value, and Gtk::LevelBar#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: %GTK_LEVEL_BAR_OFFSET_LOW, %GTK_LEVEL_BAR_OFFSET_HIGH and %GTK_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

WARNING ⚠️ The following code is in c ⚠️

static Gtk::Widget *
create_level_bar (void)
{
  Gtk::Widget *widget;
  Gtk::LevelBar *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 Gtk::LevelBar#min_value= and Gtk::LevelBar#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 %GTK_LEVEL_BAR_MODE_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.

Gtk::LevelBar as Gtk::Buildable

The Gtk::LevelBar implementation of the Gtk::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
    ┊

Gtk::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

Gtk::LevelBar uses the %GTK_ACCESSIBLE_ROLE_METER role.

Included Modules

• Gtk::Accessible
• Gtk::Buildable
• Gtk::ConstraintTarget
• Gtk::Orientable

Defined in:

Constructors

• .new : self

  Creates a new Gtk::LevelBar.

• .new(*, accessible_role : Gtk::AccessibleRole? = nil, can_focus : Bool? = nil, can_target : Bool? = nil, css_classes : Enumerable(String)? = nil, css_name : String? = nil, cursor : Gdk::Cursor? = nil, focus_on_click : Bool? = nil, focusable : Bool? = nil, halign : Gtk::Align? = nil, has_default : Bool? = nil, has_focus : Bool? = nil, has_tooltip : Bool? = nil, height_request : Int32? = nil, hexpand : Bool? = nil, hexpand_set : Bool? = nil, inverted : Bool? = nil, layout_manager : Gtk::LayoutManager? = nil, margin_bottom : Int32? = nil, margin_end : Int32? = nil, margin_start : Int32? = nil, margin_top : Int32? = nil, max_value : Float64? = nil, min_value : Float64? = nil, mode : Gtk::LevelBarMode? = nil, name : String? = nil, opacity : Float64? = nil, orientation : Gtk::Orientation? = nil, overflow : Gtk::Overflow? = nil, parent : Gtk::Widget? = nil, receives_default : Bool? = nil, root : Gtk::Root? = nil, scale_factor : Int32? = nil, sensitive : Bool? = nil, tooltip_markup : String? = nil, tooltip_text : String? = nil, valign : Gtk::Align? = nil, value : Float64? = nil, vexpand : Bool? = nil, vexpand_set : Bool? = nil, visible : Bool? = nil, width_request : Int32? = nil)
• .new_for_interval(min_value : Float64, max_value : Float64) : self

  Creates a new Gtk::LevelBar for the specified interval.

Class Method Summary

• .g_type : UInt64

  Returns the type id (GType) registered in GLib type system.

Instance Method Summary

• #add_offset_value(name : String, value : Float64) : Nil

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

• #inverted : Bool

  Returns whether the levelbar is inverted.

• #inverted=(inverted : Bool) : Nil

  Sets whether the Gtk::LevelBar is inverted.

• #inverted? : Bool
• #max_value : Float64

  Returns the max-value of the Gtk::LevelBar.

• #max_value=(value : Float64) : Nil

  Sets the max-value of the Gtk::LevelBar.

• #min_value : Float64

  Returns the min-value of theGtk::LevelBar`.

• #min_value=(value : Float64) : Nil

  Sets the min-value of the Gtk::LevelBar.

• #mode : Gtk::LevelBarMode

  Returns the #mode of the Gtk::LevelBar.

• #mode=(mode : Gtk::LevelBarMode) : Nil

  Sets the #mode of the Gtk::LevelBar.

• #offset_changed_signal
• #offset_value(name : String?, value : Float64) : Bool

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

• #remove_offset_value(name : String?) : Nil

  Removes an offset marker from a Gtk::LevelBar.

• #value : Float64

  Returns the #value of the Gtk::LevelBar.

• #value=(value : Float64) : Nil

  Sets the value of the Gtk::LevelBar.

Constructor Detail

Class Method Detail

Instance Method Detail