ChatColors class

Customisation surface for the chat's visual palette.

widget_chat is sold to many tenants — each one wants the chat surface to match their brand without forking the SDK. Rather than piling color fields onto BotConfiguration (host plumbing per session) or hardcoding them on every widget, we expose them as a Flutter ThemeExtension: hosts attach an instance to their MaterialApp.theme.extensions and every chat widget reads from it.

Every field is nullable. A null field falls back to a derived value from the ambient ColorScheme so an out-of-the-box host (no extension wired) still gets a usable, MD3-tonal chat. That also means a host can override just one field (say, the user bubble background to match their brand) and leave everything else at the sensible default.

Wiring example for a tenant:

MaterialApp(
  theme: ThemeData(
    colorScheme: ColorScheme.fromSeed(seedColor: Colors.pink),
    extensions: const [
      ChatColors(
        userBubbleBackground: Color(0xFFFCE4EC),
        userBubbleForeground: Color(0xFF7A1D3F),
      ),
    ],
  ),
  home: ChatWidget(/* ... */),
);

Inheritance

Annotations

@immutable

Constructors

ChatColors({Color? surfaceBackground, Color? botBubbleBackground, Color? userBubbleBackground, Color? botBubbleForeground, Color? userBubbleForeground, Color? botBubbleShadow}): const

Properties

botBubbleBackground → Color?: Bot message bubble background. Default: ColorScheme.surface (clean white in light themes; deep neutral in dark themes).
final
botBubbleForeground → Color?: Foreground (text + icon) color for bot bubbles. Default: ColorScheme.onSurface. Picks the readable contrast color for whatever botBubbleBackground resolves to.
final
botBubbleShadow → Color?: Drop-shadow color for bot bubbles. Default: a soft black at ~6% alpha — enough to lift the bubble off a same-color surface without looking like a Material card.
final
hashCode → int: The hash code for this object.
no setterinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
surfaceBackground → Color?: The chat surface — what sits behind the message list. Keep this slightly off-white (or off-black in dark mode) so white/gray bubbles read as raised cards rather than blending into the page. Default: ColorScheme.surfaceContainerLow.
final
type → Object: The extension's type.
no setterinherited
userBubbleBackground → Color?: User message bubble background. Default: ColorScheme.surfaceContainerHigh (a slightly darker tone than the bot bubble so the two speakers read as distinct without either looking like an error/accent surface). Override to a brand-tinted color to give visitor messages a signature.
final
userBubbleForeground → Color?: Foreground (text + icon) color for user bubbles. Default: ColorScheme.onSurface over the lighter user bubble background.
final

Methods

copyWith({Color? surfaceBackground, Color? botBubbleBackground, Color? userBubbleBackground, Color? botBubbleForeground, Color? userBubbleForeground, Color? botBubbleShadow}) → ChatColors: Creates a copy of this theme extension with the given fields replaced by the non-null parameter values.
override
lerp(covariant ThemeExtension<ChatColors>? other, double t) → ChatColors: Linearly interpolate with another ThemeExtension object.
override
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
resolveBotBubble(ColorScheme scheme) → Color
resolveBotForeground(ColorScheme scheme) → Color
resolveBotShadow(ColorScheme scheme) → Color
resolveSurface(ColorScheme scheme) → Color: Resolved chat-surface background. Pull-with-fallback so call sites stay terse.
resolveUserBubble(ColorScheme scheme) → Color
resolveUserForeground(ColorScheme scheme) → Color
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

of(BuildContext context) → ChatColors: Look up the ChatColors from a BuildContext. Returns a const empty instance when the host hasn't wired one, so call sites never deal with null.