IconButton class
A material design icon button.
An icon button is a picture printed on a Material widget that reacts to touches by filling with color (ink).
Icon buttons are commonly used in the AppBar.actions field, but they can be used in many other places as well.
If the onPressed callback is null, then the button will be disabled and will not react to touch.
Requires one of its ancestors to be a Material widget.
The hit region of an icon button will, if possible, be at least kMinInteractiveDimension pixels in size, regardless of the actual iconSize, to satisfy the touch target size requirements in the Material Design specification. The alignment controls how the icon itself is positioned within the hit region.
IconButton
that uses the Material icon "volume_up" to
increase the volume.
flutter create --sample=material.IconButton.1 mysample
IconButton
that uses the Material icon "volume_up" to
increase the volume.
double _volume = 0.0;
// ...
Widget build(BuildContext context) {
return Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
IconButton(
icon: Icon(Icons.volume_up),
tooltip: 'Increase volume by 10',
onPressed: () {
setState(() {
_volume += 10;
});
},
),
Text('Volume : $_volume')
],
);
}
Adding a filled background
Icon buttons don't support specifying a background color or other background decoration because typically the icon is just displayed on top of the parent widget's background. Icon buttons that appear in AppBar.actions are an example of this.
It's easy enough to create an icon button with a filled background using the Ink widget. The Ink widget renders a decoration on the underlying Material along with the splash and highlight InkResponse contributed by descendant widgets.
flutter create --sample=material.IconButton.2 mysample
Widget build(BuildContext context) {
return Material(
color: Colors.white,
child: Center(
child: Ink(
decoration: const ShapeDecoration(
color: Colors.lightBlue,
shape: CircleBorder(),
),
child: IconButton(
icon: Icon(Icons.android),
color: Colors.white,
onPressed: () {},
),
),
),
);
}
See also:
- Icons, a library of predefined icons.
- BackButton, an icon button for a "back" affordance which adapts to the current platform's conventions.
- CloseButton, an icon button for closing pages.
- AppBar, to show a toolbar at the top of an application.
- TextButton, ElevatedButton, OutlinedButton, for buttons with text labels and an optional icon.
- InkResponse and InkWell, for the ink splash effect itself.
- Inheritance
- Object
- DiagnosticableTree
- Widget
- StatelessWidget
- IconButton
Constructors
-
IconButton({Key key,
double iconSize: 24.0, VisualDensity visualDensity, EdgeInsetsGeometry padding: const EdgeInsets.all(8.0), AlignmentGeometry alignment: Alignment.center, double splashRadius, @required Widget icon, Color color, Color focusColor, Color hoverColor, Color highlightColor, Color splashColor, Color disabledColor, @required VoidCallback onPressed, MouseCursor mouseCursor: SystemMouseCursors.click, FocusNode focusNode, bool autofocus: false, String tooltip, bool enableFeedback: true, BoxConstraints constraints} ) -
Creates an icon button. [...]
const
Properties
- alignment → AlignmentGeometry
-
Defines how the icon is positioned within the IconButton. [...]
final
- autofocus → bool
-
True if this widget will be selected as the initial focus when no other
node in its scope is currently focused. [...]
final
- color → Color
-
The color to use for the icon inside the button, if the icon is enabled.
Defaults to leaving this up to the icon widget. [...]
final
- constraints → BoxConstraints
-
Optional size constraints for the button. [...]
final
- disabledColor → Color
-
The color to use for the icon inside the button, if the icon is disabled.
Defaults to the ThemeData.disabledColor of the current Theme. [...]
final
- enableFeedback → bool
-
Whether detected gestures should provide acoustic and/or haptic feedback. [...]
final
- focusColor → Color
-
The color for the button's icon when it has the input focus. [...]
final
- focusNode → FocusNode
-
An optional focus node to use as the focus node for this widget. [...]
final
- hashCode → int
-
The hash code for this object. [...]
@nonVirtual, read-only, inherited
- highlightColor → Color
-
The secondary color of the button when the button is in the down (pressed)
state. The highlight color is represented as a solid color that is overlaid over the
button color (if any). If the highlight color has transparency, the button color
will show through. The highlight fades in quickly as the button is held down. [...]
final
- hoverColor → Color
-
The color for the button's icon when a pointer is hovering over it. [...]
final
- icon → Widget
-
The icon to display inside the button. [...]
final
- iconSize → double
-
The size of the icon inside the button. [...]
final
- key → Key
-
Controls how one widget replaces another widget in the tree. [...]
final, inherited
- mouseCursor → MouseCursor
-
The cursor for a mouse pointer when it enters or is hovering over the
button. [...]
final
- onPressed → VoidCallback
-
The callback that is called when the button is tapped or otherwise activated. [...]
final
- padding → EdgeInsetsGeometry
-
The padding around the button's icon. The entire padded icon will react
to input gestures. [...]
final
- runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
- splashColor → Color
-
The primary color of the button when the button is in the down (pressed) state.
The splash is represented as a circular overlay that appears above the
highlightColor overlay. The splash overlay has a center point that matches
the hit point of the user touch event. The splash overlay will expand to
fill the button area if the touch is held for long enough time. If the splash
color has transparency then the highlight and button color will show through. [...]
final
- splashRadius → double
-
The splash radius. [...]
final
- tooltip → String
-
Text that describes the action that will occur when the button is pressed. [...]
final
- visualDensity → VisualDensity
-
Defines how compact the icon button's layout will be. [...]
final
Methods
-
build(
BuildContext context ) → Widget -
Describes the part of the user interface represented by this widget. [...]
override
-
createElement(
) → StatelessElement -
Creates a StatelessElement to manage this widget's location in the tree. [...]
inherited
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of DiagnosticsNode objects describing this node's
children. [...]
@protected, inherited
-
debugFillProperties(
DiagnosticPropertiesBuilder properties ) → void -
Add additional properties associated with the node. [...]
override
-
noSuchMethod(
Invocation invocation ) → dynamic -
Invoked when a non-existent 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 -
Returns a string representation of this object.
inherited
-
toStringDeep(
{String prefixLineOne: '', String prefixOtherLines, DiagnosticLevel minLevel: DiagnosticLevel.debug} ) → 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. [...]
@nonVirtual, inherited