StreamMessageComposerAttachment class

A styled container that wraps composer attachment content with a themed background, shape, and border.

StreamMessageComposerAttachment sizes itself to its child, paints a rounded surface behind it, and clips the child to that shape. An outlined border is composed onto the shape. The container also adds an outer margin so adjacent attachments in a row don't touch.

When onRemovePressed is non-null, a circular StreamRemoveControl is overlaid at the top-end corner, slightly outside the shape so it visually attaches to the edge.

{@tool snippet}

Basic usage — a rounded card with a subtle 1px border:

StreamMessageComposerAttachment(
  onRemovePressed: () => removeAttachment(),
  child: MyAttachmentContent(),
)

{@end-tool}

{@tool snippet}

With explicit style overrides:

StreamMessageComposerAttachment(
  style: StreamMessageComposerAttachmentThemeData(
    backgroundColor: Colors.blue.shade50,
    side: BorderSide(color: Colors.blue.shade200),
  ),
  child: MyAttachmentContent(),
)

{@end-tool}

Theming

StreamMessageComposerAttachment uses StreamMessageComposerAttachmentThemeData for default styling — background color, shape, border side, and outer padding. Per-instance style takes precedence over the inherited theme.

See also:

• StreamMessageComposerAttachmentTheme, for customizing attachment containers globally.
• StreamRemoveControl, the remove button shown when onRemovePressed is provided.
• StreamMessageAttachment, the analogous container for message-list attachments.
• DefaultStreamMessageComposerAttachment, the default visual implementation.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• StreamMessageComposerAttachment

Constructors

StreamMessageComposerAttachment({Key? key, required Widget child, VoidCallback? onRemovePressed, String? semanticLabel, StreamMessageComposerAttachmentThemeData? style})

Creates a composer attachment container.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

props → StreamMessageComposerAttachmentProps

The properties that configure this attachment container.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

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