CircularProgressIndicator class
A Material Design circular progress indicator, which spins to indicate that the application is busy.
A widget that shows progress along a circle. There are two kinds of circular progress indicators:
- Determinate. Determinate progress indicators have a specific value at each point in time, and the value should increase monotonically from 0.0 to 1.0, at which time the indicator is complete. To create a determinate progress indicator, use a non-null value between 0.0 and 1.0.
- Indeterminate. Indeterminate progress indicators do not have a specific value at each point in time and instead indicate that progress is being made without indicating how much progress remains. To create an indeterminate progress indicator, use a null value.
The indicator arc is displayed with valueColor, an animated value. To
specify a constant color use: AlwaysStoppedAnimation<Color>(color)
.
This example shows a CircularProgressIndicator with a changing value.
link
To create a local project with this code sample, run:
flutter create --sample=material.CircularProgressIndicator.1 mysample
This sample shows the creation of a CircularProgressIndicator with a changing value.
When toggling the switch, CircularProgressIndicator uses a determinate value.
As described in: https://m3.material.io/components/progress-indicators/overview
link
To create a local project with this code sample, run:
flutter create --sample=material.CircularProgressIndicator.2 mysample
See also:
- LinearProgressIndicator, which displays progress along a line.
- RefreshIndicator, which automatically displays a CircularProgressIndicator when the underlying vertical scrollable is overscrolled.
- material.io/design/components/progress-indicators.html#circular-progress-indicators
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatefulWidget
- ProgressIndicator
- CircularProgressIndicator
- Implementers
Constructors
-
CircularProgressIndicator({Key? key, double? value, Color? backgroundColor, Color? color, Animation<
Color?> ? valueColor, double strokeWidth = 4.0, double strokeAlign = strokeAlignCenter, String? semanticsLabel, String? semanticsValue, StrokeCap? strokeCap}) -
Creates a circular progress indicator.
const
-
CircularProgressIndicator.adaptive({Key? key, double? value, Color? backgroundColor, Animation<
Color?> ? valueColor, double strokeWidth = 4.0, String? semanticsLabel, String? semanticsValue, StrokeCap? strokeCap, double strokeAlign = strokeAlignCenter}) -
Creates an adaptive progress indicator that is a
CupertinoActivityIndicator in TargetPlatform.iOS & TargetPlatform.macOS and CircularProgressIndicator in
material theme/non-Apple platforms.
const
Properties
- backgroundColor → Color?
-
Color of the circular track being filled by the circular indicator.
no setteroverride
- color → Color?
-
The progress indicator's color.
finalinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- semanticsLabel → String?
-
The SemanticsProperties.label for this progress indicator.
finalinherited
- semanticsValue → String?
-
The SemanticsProperties.value for this progress indicator.
finalinherited
- strokeAlign → double
-
The relative position of the stroke on a CircularProgressIndicator.
final
- strokeCap → StrokeCap?
-
The progress indicator's line ending.
final
- strokeWidth → double
-
The width of the line used to draw the circle.
final
- value → double?
-
If non-null, the value of this progress indicator.
finalinherited
-
valueColor
→ Animation<
Color?> ? -
The progress indicator's color as an animated value.
finalinherited
Methods
-
createElement(
) → StatefulElement -
Creates a StatefulElement to manage this widget's location in the tree.
inherited
-
createState(
) → State< CircularProgressIndicator> -
Creates the mutable state for this widget at a given location in the tree.
override
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of DiagnosticsNode objects describing this node's
children.
inherited
-
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
toDiagnosticsNode(
{String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode -
Returns a debug representation of the object that is used by debugging
tools and by DiagnosticsNode.toStringDeep.
inherited
-
toString(
{DiagnosticLevel minLevel = DiagnosticLevel.info}) → String -
A string representation of this object.
inherited
-
toStringDeep(
{String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String -
Returns a string representation of this node and its descendants.
inherited
-
toStringShallow(
{String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String -
Returns a one-line detailed description of the object.
inherited
-
toStringShort(
) → String -
A short, textual description of this widget.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited
Constants
- strokeAlignCenter → const double
- The indicator stroke is drawn on the center of the indicator path, with half of the strokeWidth on the inside, and the other half on the outside of the path.
- strokeAlignInside → const double
- The indicator stroke is drawn fully inside of the indicator path.
- strokeAlignOutside → const double
- The indicator stroke is drawn on the outside of the indicator path.