StreamMessageLayoutData class

The layout data for a message.

Combines positional properties — alignment (start vs end), stackPosition (single, top, middle, bottom) — with environmental context — channelKind (direct vs group), listKind (channel vs thread), presentation (standard vs preview) — and content classification — contentKind (standard, singleAttachment, jumbomoji) — into a single value that StreamMessageLayoutProperty resolvers use to compute layout-dependent styling.

{@tool snippet}

Create layout data for an end-aligned, single image message at the top of a stack in a group channel:

const layout = StreamMessageLayoutData(
  alignment: StreamMessageAlignment.end,
  stackPosition: StreamMessageStackPosition.top,
  channelKind: StreamMessageChannelKind.group,
  listKind: StreamMessageListKind.channel,
  contentKind: StreamMessageContentKind.singleAttachment,
  presentation: StreamMessagePresentation.standard,
);

print(layout.alignment);       // StreamMessageAlignment.end
print(layout.stackPosition);   // StreamMessageStackPosition.top
print(layout.channelKind);     // StreamMessageChannelKind.group
print(layout.listKind);        // StreamMessageListKind.channel
print(layout.contentKind);     // StreamMessageContentKind.singleAttachment
print(layout.presentation);    // StreamMessagePresentation.standard

{@end-tool}

See also:

• StreamMessageAlignment, the horizontal alignment axis.
• StreamMessageStackPosition, the vertical stacking axis.
• StreamMessageChannelKind, the kind of channel the message is displayed in.
• StreamMessageListKind, the kind of list the message is displayed in.
• StreamMessageContentKind, the kind of content the message carries.
• StreamMessagePresentation, how the message is presented to the user.
• StreamMessageLayoutProperty, which resolves values from this context.

Annotations

• @immutable

Constructors

StreamMessageLayoutData({StreamMessageAlignment alignment = .start, StreamMessageStackPosition stackPosition = .single, StreamMessageChannelKind channelKind = .group, StreamMessageListKind listKind = .channel, StreamMessageContentKind contentKind = .standard, StreamMessagePresentation presentation = .standard})

Creates message layout data.

const

Properties

alignment → StreamMessageAlignment

The horizontal alignment of the message.

final

channelKind → StreamMessageChannelKind

The kind of channel this message is displayed in.

final

contentKind → StreamMessageContentKind

The kind of content this message carries.

final

hashCode → int

The hash code for this object.

no setter, override

listKind → StreamMessageListKind

The kind of list this message is displayed in.

final

presentation → StreamMessagePresentation

How this message is presented to the user.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

stackPosition → StreamMessageStackPosition

The position of the message within a consecutive stack.

final

Methods

copyWith({StreamMessageAlignment? alignment, StreamMessageStackPosition? stackPosition, StreamMessageChannelKind? channelKind, StreamMessageListKind? listKind, StreamMessageContentKind? contentKind, StreamMessagePresentation? presentation}) → StreamMessageLayoutData

Returns a copy of this StreamMessageLayoutData with the given fields replaced with new values.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

override