HelpButton class

A help button appears within a view and opens app-specific help documentation when clicked. For help documentation creation guidance, see Help. All help buttons are circular, consistently sized buttons that contain a question mark icon. Whenever possible, open a help topic related to the current context. For example, the Rules pane of Mail preferences includes a help button. When clicked, it opens directly to a Rules preferences help topic.

Inheritance

Constructors

HelpButton({Key? key, Color? color, Color? disabledColor, VoidCallback? onPressed, double? pressedOpacity = 0.4, AlignmentGeometry alignment = Alignment.center, String? semanticLabel, MouseCursor? mouseCursor = SystemMouseCursors.basic})
pressedOpacity, if non-null, must be in the range if 0.0 to 1.0
const

Properties

alignment AlignmentGeometry
The alignment of the button's child.
final
color Color?
The color of the button's background.
final
disabledColor Color?
The color of the button's background when the button is disabled.
final
enabled bool
Whether the button is enabled or disabled. Buttons are disabled by default. To enable a button, set its onPressed property to a non-null value.
no setter
hashCode int
The hash code for this object.
no setterinherited
key Key?
Controls how one widget replaces another widget in the tree.
finalinherited
mouseCursor MouseCursor?
The mouse cursor to use when hovering over this widget.
final
onPressed VoidCallback?
The callback that is called when the button is tapped or otherwise activated.
final
pressedOpacity double?
The opacity that the button will fade to when it is pressed. The button will have an opacity of 1.0 when it is not pressed.
final
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
semanticLabel String?
The semantic label used by screen readers.
final

Methods

createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() HelpButtonState
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.
override
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}) 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