BubbleGroupBuilder class

A widget that builds a vertically stacked list of chat bubbles with automatic message grouping.

Consecutive messages from the same sender (within groupingThreshold) are grouped together. The last message in each group receives a tail (GroupInfo.showTail = true); earlier messages in the same group do not.

Use itemBuilder to construct the appropriate bubble widget. The GroupInfo parameter tells you whether to show the tail, an avatar, etc.

Example

final messages = ['Hello', 'How are you?', 'Good thanks!'];
final senders  = ['alice', 'alice', 'bob'];

BubbleGroupBuilder(
  itemCount: messages.length,
  senderIdOf: (i) => senders[i],
  itemBuilder: (context, i, info) => BubbleNormal(
    text: messages[i],
    isSender: senders[i] == 'bob',
    tail: info.showTail,
    color: senders[i] == 'bob'
        ? const Color(0xFFE8E8EE)
        : const Color(0xFF1B97F3),
  ),
)

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• BubbleGroupBuilder

Constructors

BubbleGroupBuilder({Key? key, required int itemCount, required String senderIdOf(int index), required Widget itemBuilder(BuildContext context, int index, GroupInfo info), DateTime? timestampOf(int index)?, Duration groupingThreshold = const Duration(minutes: 1), double itemSpacing = 2.0, double groupSpacing = 8.0})

Creates a BubbleGroupBuilder widget

const

Properties

groupingThreshold → Duration

Maximum time gap between two consecutive messages from the same sender before they are split into separate groups. Defaults to 1 minute.

final

groupSpacing → double

Vertical spacing between separate groups

final

hashCode → int

The hash code for this object.

no setter, inherited

itemBuilder → Widget Function(BuildContext context, int index, GroupInfo info)

Builds the bubble widget for index.

final

itemCount → int

Total number of messages

final

itemSpacing → double

Vertical spacing between bubbles within the same group

final

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

senderIdOf → String Function(int index)

Returns the sender identifier for the message at index

final

timestampOf → DateTime? Function(int index)?

Optional: returns the send timestamp for the message at index. Used to break groups when a time gap exceeds groupingThreshold.

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