Struct gtk4::LevelBar [−][src]
pub struct LevelBar(_);Expand description
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 <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.
Implements
WidgetExt, glib::ObjectExt, AccessibleExt, BuildableExt, ConstraintTargetExt, OrientableExt, WidgetExtManual, AccessibleExtManual
Implementations
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.
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
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 connect_offset_changed<F: Fn(&Self, &str) + 'static>(
&self,
detail: Option<&str>,
f: F
) -> SignalHandlerId
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
Trait Implementations
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Returns the type identifier of Self.
Auto Trait Implementations
impl RefUnwindSafe for LevelBar
impl UnwindSafe for LevelBar
Blanket Implementations
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T. Read more
Upcasts an object to a reference of its superclass or interface T. Read more
Tries to downcast to a subclass or interface implementor T. Read more
Tries to downcast to a reference of its subclass or interface implementor T. Read more
Tries to cast to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Casts to T unconditionally. Read more
Casts to &T unconditionally. Read more
Returns true if the object is an instance of (can be cast to) T.
pub fn set_property<'a, N, V>(
&self,
property_name: N,
value: V
) -> Result<(), BoolError> where
N: Into<&'a str>,
V: ToValue,
pub fn set_property_from_value<'a, N>(
&self,
property_name: N,
value: &Value
) -> Result<(), BoolError> where
N: Into<&'a str>,
pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value)]
) -> Result<(), BoolError>
pub fn has_property<'a, N>(&self, property_name: N, type_: Option<Type>) -> bool where
N: Into<&'a str>,
pub fn find_property<'a, N>(&self, property_name: N) -> Option<ParamSpec> where
N: Into<&'a str>,
Safety Read more
Safety Read more
Safety Read more
Safety Read more
pub fn connect<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value> + Send + Sync,
Same as connect but takes a SignalId instead of a signal name.
pub fn connect_local<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value>,
Same as connect_local but takes a SignalId instead of a signal name.
pub unsafe fn connect_unsafe<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: Fn(&[Value]) -> Option<Value>,
Same as connect_unsafe but takes a SignalId instead of a signal name.
Emit signal by signal id.
Same as emit but takes Value for the arguments.
Emit signal by its name.
Same as emit_by_name but takes Value for the arguments.
Emit signal with details by signal id.
Same as emit_with_details but takes Value for the arguments.
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync,
pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec),
pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec),
pub fn bind_property<'a, O, N, M>(
&'a self,
source_property: N,
target: &'a O,
target_property: M
) -> BindingBuilder<'a> where
O: ObjectType,
N: Into<&'a str>,
M: Into<&'a str>,
Returns a SendValue clone of self.