TextArea class
A multiline text area input field for the Alter Design System built on TextInput.
Features:
- Configurable
lines(default: 4) which reserves multiline visual space. - Character limit counting and validation.
- Reuses TextInput and InputControl for full design system tokens, states, and error handling.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatelessWidget
- TextArea
Constructors
-
TextArea({Key? key, String? label = 'Description', bool isRequired = false, int? characterLimit = 200, InputControlType type = InputControlType.gray, int lines = 4, int? minLines, IconData? leftIcon, Widget? leftIconWidget, String? prefix, Widget? prefixWidget, String placeholder = 'Enter description...', String? value, TextEditingController? controller, FocusNode? focusNode, String? suffix, Widget? suffixWidget, ButtonIconGhost? rightButton, bool isError = false, bool showErrorMessage = true, String errorMessage = 'Error Message', List<
String> ? errorMessages, Widget? errorIconWidget, FormFieldValidator<String> ? validator, FormFieldSetter<String> ? onSaved, AutovalidateMode? autovalidateMode, bool enabled = true, bool readOnly = false, bool autofocus = false, TextInputType? keyboardType, List<TextInputFormatter> ? inputFormatters, ValueChanged<String> ? onChanged, ValueChanged<String> ? onSubmitted, VoidCallback? onTap}) -
Creates a TextArea multiline input instance.
const
Properties
- autofocus → bool
-
Whether the text area autofocuses.
final
- autovalidateMode → AutovalidateMode?
-
Autovalidate mode for form integration.
final
- characterLimit → int?
-
Maximum allowed character limit counter displayed on typing.
final
- controller → TextEditingController?
-
External text editing controller.
final
- enabled → bool
-
Whether the text area is interactive.
final
- errorIconWidget → Widget?
-
Custom icon widget override for the error message banner.
final
- errorMessage → String
-
Default error message text.
final
-
errorMessages
→ List<
String> ? -
Optional list of multiple error messages.
final
- focusNode → FocusNode?
-
Focus node controlling input focus.
final
- hashCode → int
-
The hash code for this object.
no setterinherited
-
inputFormatters
→ List<
TextInputFormatter> ? -
Formatters applied to the text field input.
final
- isError → bool
-
Whether the input is in an explicit error state.
final
- isRequired → bool
-
Whether to display a red required asterisk next to the label.
final
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- keyboardType → TextInputType?
-
Virtual keyboard type for software keyboards.
final
- label → String?
-
Label text displayed above the text area.
final
- leftIcon → IconData?
-
Leading icon data.
final
- leftIconWidget → Widget?
-
Custom leading widget override.
final
- lines → int
-
Number of text lines determining the height of the area.
final
- minLines → int?
-
Optional minimum number of lines for dynamic expansion.
final
-
onChanged
→ ValueChanged<
String> ? -
Callback executed on value changes.
final
-
onSaved
→ FormFieldSetter<
String> ? -
Form field on-saved callback.
final
-
onSubmitted
→ ValueChanged<
String> ? -
Callback executed on keyboard submit.
final
- onTap → VoidCallback?
-
Callback executed when the input container is tapped.
final
- placeholder → String
-
Hint placeholder text.
final
- prefix → String?
-
Prefix text displayed before the input value.
final
- prefixWidget → Widget?
-
Custom prefix widget override.
final
- readOnly → bool
-
Whether the text area is read-only.
final
- rightButton → ButtonIconGhost?
-
Trailing action button (e.g. ButtonIconGhost).
final
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- showErrorMessage → bool
-
Whether to render the error message beneath the field.
final
- suffix → String?
-
Suffix descriptor text displayed at the trailing end.
final
- suffixWidget → Widget?
-
Custom suffix widget override.
final
- type → InputControlType
-
Surface background and border style variant.
final
-
validator
→ FormFieldValidator<
String> ? -
Form field validation callback.
final
- value → String?
-
Initial or bound value string.
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.
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
- version → const String
- Component version for reference. v2.4.0: Added optional keyboardType (TextInputType?) fallback passthrough. v2.3.0: Streamlined multiline sizing: Clean minLines and lines (max height) configuration. Non-adaptive fixed height when minLines is null; adaptive auto-expanding height up to lines when minLines is provided. v2.1.0: Aligned with InputControl v2.1.0 & TextInput v2.1.0 (removed showLabel/showCharacterLimit; labelBar renders when label is provided). v2.0.0: Aligned with InputControl v2.0.0 & TextInput v2.0.0 (removed statusOverride and redundant hasX booleans in favor of clean nullable props). v1.0.0: Initial release of TextArea wrapper built on TextInput with configurable lines height.