call_ui_kit

A ready-to-use Flutter call UI kit that handles personal audio calls, personal video calls, and group calls. Zero external dependencies — only Flutter SDK.

Inspired by WhatsApp call design. Fully customizable through themes and localized strings.

Screenshots

Screenshot	Description
Personal Audio Call	1:1 audio call with caller avatar, status text, and controls
Personal Video Call	1:1 video call with draggable PiP, flip camera, and more sheet
Screen Share	Group call with screen sharing and participant thumbnails
More Sheet	Customizable bottom sheet with encryption label
Speaker View	7+ participants — active speaker prominent with thumbnail row
Speaking Border	Animated green border on the active speaker's tile

Features

Personal audio call — caller avatar, call status, speaker toggle
Personal video call — remote/local video, draggable PiP, camera flip, swap on tap
Group video call — adaptive grid (2x2, 2x3), speaker view (7+ participants), thumbnail row
Group audio call — participant tiles with avatars, speaking indicators
Screen sharing — dedicated layout with screen share banner and stop button
Auto-hide controls — top bar, bottom bar, and side buttons hide after 4 seconds
Participants panel — draggable bottom sheet with host actions (mute, remove)
"More" bottom sheet — customizable actions sheet with encryption label
Full localization — every user-facing string is configurable via CallStrings
Full theming — every color is configurable via CallTheme
Speaking indicators — animated sine-wave bars and glowing tile borders
Signal strength — 4-level indicator per participant
PiP view — draggable and corner-snapping; follows the controls, expanding into the bar areas while they are hidden and keeping the corner you left it in
Reconnection-safe video — opaque video surfaces and per-build participant data, so a recreated renderer never leaves a blank or stale frame

Installation

Add to your pubspec.yaml:

dependencies:
  call_ui_kit: ^0.5.0

Quick Start

Personal Audio Call

CallScreen(
  callerName: 'Sarah Johnson',
  callerAvatarUrl: 'https://example.com/avatar.jpg',
  callType: CallType.audio,
  localParticipant: const CallParticipant(
    id: 'local',
    displayName: 'You',
    isLocalUser: true,
  ),
  isMuted: _isMuted,
  isSpeakerOn: _isSpeakerOn,
  callStatusText: '02:45',
  onEndCall: () => Navigator.pop(context),
  onToggleMute: () => setState(() => _isMuted = !_isMuted),
  onToggleSpeaker: () => setState(() => _isSpeakerOn = !_isSpeakerOn),
)

Personal Video Call

CallScreen(
  callerName: 'Alex Rivera',
  callerAvatarUrl: 'https://example.com/avatar.jpg',
  callType: CallType.video,
  localParticipant: const CallParticipant(
    id: 'local',
    displayName: 'You',
    isLocalUser: true,
  ),
  localVideoWidget: localVideoView,   // your camera widget
  remoteVideoWidget: remoteVideoView, // remote camera widget
  isMuted: _isMuted,
  isCameraOff: _isCameraOff,
  isSpeakerOn: _isSpeakerOn,
  callStatusText: '04:23',
  onEndCall: () => Navigator.pop(context),
  onToggleMute: () => setState(() => _isMuted = !_isMuted),
  onToggleCamera: () => setState(() => _isCameraOff = !_isCameraOff),
  onToggleSpeaker: () => setState(() => _isSpeakerOn = !_isSpeakerOn),
  onFlipCamera: () => /* flip camera logic */,
)

Group Video Call

CallScreen(
  callerName: 'Team Meeting',
  isGroupCall: true,
  callType: CallType.video,
  localParticipant: const CallParticipant(
    id: 'local',
    displayName: 'You',
    isLocalUser: true,
    isHost: true,
  ),
  participants: [
    CallParticipant(
      id: '2',
      displayName: 'Alex Rivera',
      avatarUrl: 'https://example.com/alex.jpg',
      videoWidget: alexVideoView, // or null if camera off
      isSpeaking: true,
    ),
    CallParticipant(
      id: '3',
      displayName: 'Priya Sharma',
      avatarUrl: 'https://example.com/priya.jpg',
      isMuted: true,
      isCameraOff: true,
    ),
    // ... more participants
  ],
  isMuted: _isMuted,
  isCameraOff: _isCameraOff,
  isSpeakerOn: _isSpeakerOn,
  callStatusText: '12:07',
  onEndCall: () => Navigator.pop(context),
  onToggleMute: () => setState(() => _isMuted = !_isMuted),
  onToggleCamera: () => setState(() => _isCameraOff = !_isCameraOff),
  onToggleSpeaker: () => setState(() => _isSpeakerOn = !_isSpeakerOn),
  onAddParticipant: () => /* invite logic */,
  onMuteParticipant: (p) => /* mute participant */,
  onRemoveParticipant: (p) => /* remove participant */,
)

CallScreen(
  callerName: 'Design Review',
  isGroupCall: true,
  callType: CallType.video,
  localParticipant: localParticipant,
  participants: participants,
  screenShareWidget: screenShareView, // the shared screen widget
  isScreenSharing: _isLocalSharing,
  onStopScreenShare: () => setState(() => _isLocalSharing = false),
  // ... other required params
)

Incoming / Outgoing Call

IncomingCallScreen(
  callerName: 'Alex Rivera',
  callerAvatarUrl: 'https://example.com/avatar.jpg',
  callType: CallType.video,
  onAccept: _acceptCall,
  onDecline: () => Navigator.pop(context),
)

OutgoingCallScreen(
  callerName: 'Alex Rivera',
  callType: CallType.video,
  isMuted: _isMuted,
  isSpeakerOn: _isSpeakerOn,
  onEndCall: () => Navigator.pop(context),
  onToggleMute: () => setState(() => _isMuted = !_isMuted),
  onToggleSpeaker: () => setState(() => _isSpeakerOn = !_isSpeakerOn),
)

API Reference

CallScreen

The main widget. All UI is driven by the parameters you pass — the kit does not manage call state.

Required Parameters

Parameter	Type	Description
`callerName`	`String`	Caller or group name shown in the top bar
`localParticipant`	`CallParticipant`	The local user's participant data
`onEndCall`	`VoidCallback`	Called when end-call button is tapped
`onToggleMute`	`VoidCallback`	Called when mute button is tapped
`onToggleSpeaker`	`VoidCallback`	Called when speaker button is tapped

Optional Parameters

Parameter	Type	Default	Description
`callerAvatarUrl`	`String?`	`null`	Avatar URL for the caller
`isGroupCall`	`bool`	`false`	Enables group call layout
`callType`	`CallType`	`CallType.video`	`.audio` or `.video`
`participants`	`List<CallParticipant>`	`[]`	Remote participants (group call)
`localVideoWidget`	`Widget?`	`null`	Local camera stream widget
`remoteVideoWidget`	`Widget?`	`null`	Remote camera stream widget (personal call)
`screenShareWidget`	`Widget?`	`null`	Screen share stream widget
`isMuted`	`bool`	`false`	Local mic muted state
`isCameraOff`	`bool`	`false`	Local camera off state
`isSpeakerOn`	`bool`	`false`	Speaker active state
`isScreenSharing`	`bool`	`false`	Local screen sharing state
`connectionState`	`CallConnectionState`	`.connected`	Shows a persistent "Connecting…"/"Reconnecting…" banner
`showEncryptionLabel`	`bool`	`true`	Show encryption label in "more" sheet
`theme`	`CallTheme`	`CallTheme.whatsApp()`	Color theme
`strings`	`CallStrings?`	`null` (English defaults)	Localized strings
`callStatusText`	`String?`	`null`	Status text override (e.g. "02:45")
`callStatusListenable`	`ValueListenable<String>?`	`null`	Status text for values that tick; rebuilds only the status line

Optional Callbacks

All optional callbacks — when null, the corresponding button is hidden.

Callback	Type	Description
`onToggleCamera`	`VoidCallback?`	Camera toggle button
`onFlipCamera`	`VoidCallback?`	Flip camera button (top bar)
`onToggleScreenShare`	`VoidCallback?`	Screen share button (bottom bar)
`onStopScreenShare`	`VoidCallback?`	Stop button on screen share banner
`onAddParticipant`	`VoidCallback?`	Add participant button (right side)
`onEffects`	`VoidCallback?`	Effects button (right side)
`onMinimize`	`VoidCallback?`	Minimize/PiP button (top bar)
`onMuteParticipant`	`void Function(CallParticipant)?`	Host mutes a participant
`onMuteAll`	`VoidCallback?`	Host taps "Mute all" in the participants panel
`onRemoveParticipant`	`void Function(CallParticipant)?`	Host removes a participant
`moreSheetBuilder`	`Widget Function(BuildContext, CallTheme)?`	Custom "more" sheet content

CallParticipant

Immutable data model for a single participant. Supports copyWith() and proper equality (==/hashCode).

const CallParticipant({
  required String id,
  required String displayName,
  String? avatarUrl,
  bool isMuted = false,
  bool isCameraOff = false,
  bool isSpeaking = false,
  bool isScreenSharing = false,
  bool isHost = false,
  bool isLocalUser = false,
  SignalStrength signalStrength = SignalStrength.excellent,
  Widget? videoWidget,
  Widget? screenShareWidget,
})

Field	Description
`id`	Unique identifier for the participant
`displayName`	Name shown on tile and in participant list
`avatarUrl`	Network image URL; falls back to colored initials
`isMuted`	Shows mute icon on tile
`isCameraOff`	Shows avatar instead of video
`isSpeaking`	Activates animated speaking border and indicator
`isScreenSharing`	Shows screen share badge
`isHost`	Shows host badge; enables host actions in panel
`isLocalUser`	Marks as local user
`signalStrength`	`.excellent`, `.good`, `.poor`, or `.none`
`videoWidget`	The live video stream widget
`screenShareWidget`	The screen share stream widget

CallTheme

Controls all colors. Use CallTheme.whatsApp() as a starting point and copyWith() to customize.

CallTheme(
  background: Color(0xFF000000),
  barBackground: Color(0xFF1C1C1E),
  buttonBackground: Color(0xFF2C2C2E),
  endCallColor: Color(0xFFE53935),
  speakingColor: Color(0xFF25D366),
  speakerActiveBackground: Colors.white,
  speakerActiveIconColor: Colors.black,
  textPrimary: Colors.white,
  textSecondary: Color(0xFFAAAAAA),
  dividerColor: Color(0xFF3A3A3C),
)

Custom theme example:

final myTheme = const CallTheme.whatsApp().copyWith(
  endCallColor: Colors.red,
  speakingColor: Colors.blue,
);

CallStrings

Every user-facing string is configurable. Use CallStrings.english() as default, or provide your own for localization.

CallStrings(
  calling: 'Calling...',
  cameraIsOff: 'Camera is off',
  you: 'You',
  endToEndEncrypted: 'End-to-end encrypted',
  shareScreen: 'Share screen',
  sendMessage: 'Send message',
  participants: 'Participants',
  shareCallLink: 'Share call link',
  cancel: 'Cancel',
  stop: 'Stop',
  youAreSharingYourScreen: 'You are sharing your screen',
  speaking: 'Speaking',
  muted: 'Muted',
  muteAll: 'Mute all',
  invite: 'Invite',
  mute: 'Mute',
  unmute: 'Unmute',
  removeFromCall: 'Remove from call',
  pictureInPicture: 'Picture in picture',
  addParticipant: 'Add participant',
  flipCamera: 'Flip camera',
  effects: 'Effects',
  connecting: 'Connecting…',      // optional, defaulted
  reconnecting: 'Reconnecting…',  // optional, defaulted
  isSharingScreen: (name) => '$name is sharing their screen',
  participantsCount: (count) => '$count participant${count == 1 ? '' : 's'}',
  moreParticipants: (count) => '+$count more',
)

CallType

enum CallType { audio, video }

CallConnectionState

enum CallConnectionState { connected, connecting, reconnecting }

Pass it to CallScreen.connectionState. Anything other than connected shows a persistent banner under the top bar, using CallStrings.connecting / CallStrings.reconnecting. The banner is never auto-hidden.

SignalStrength

enum SignalStrength { excellent, good, poor, none }

Reconnection

This kit is presentational: it renders the renderer widgets you hand it, in place. That matters when a call reconnects.

When a call drops, most WebRTC stacks dispose the old renderer and create a new one. If the widget you pass has the same type and no key as the previous one, Flutter treats it as an update to the existing element rather than a new widget — initState does not re-run, and a renderer widget that subscribed to the old (now dead) texture keeps painting nothing.

Give video widgets a key tied to renderer identity. Bump a generation counter whenever you recreate a renderer:

int _rendererGeneration = 0;

void _onReconnected() {
  // ... recreate RTCVideoRenderer instances ...
  setState(() => _rendererGeneration++);
}

CallScreen(
  // ...
  connectionState: _isReconnecting
      ? CallConnectionState.reconnecting
      : CallConnectionState.connected,
  localVideoWidget: RTCVideoView(
    _localRenderer,
    key: ValueKey('local-$_rendererGeneration'),
  ),
  remoteVideoWidget: RTCVideoView(
    _remoteRenderer,
    key: ValueKey('remote-$_rendererGeneration'),
  ),
)

The same applies to CallParticipant.videoWidget and screenShareWidget in group calls.

Two things the kit guarantees on its side:

Every externally-provided video widget is mounted on an opaque VideoSurface. A renderer that paints nothing — because its texture is being attached, was disposed, or threw during paint — shows as black, never as a transparent hole in the UI.
Participant data is read fresh on every build. Replacing a participant's videoWidget via copyWith takes effect immediately, even though CallParticipant equality deliberately ignores widget fields.

Performance

Two host-side habits decide how much work a call screen does per second. Both are measured by test/screens/call_screen_rebuild_test.dart.

Push ticking values through a listenable. A call-duration timer updated via setState re-runs CallScreen.build every second, and with it every video surface: with three participants that is 30 extra video widget builds over ten seconds. Pass callStatusListenable instead and only the status line rebuilds:

final _callStatus = ValueNotifier<String>('00:00');

// ... a periodic timer writes into _callStatus.value, no setState involved.

CallScreen(
  callStatusListenable: _callStatus,  // instead of callStatusText
  // ...
)

Hold renderer widgets in fields, don't build them inline. Constructing RTCVideoView(...) inside build hands the kit a new instance every rebuild, so Flutter cannot skip the video subtree. Build them once per renderer generation (see Reconnection) and store them:

late Widget _localVideo;   // rebuilt only when the renderer changes
late Widget _remoteVideo;

With both in place, a ticking timer costs one Text rebuild — zero video rebuilds. example/lib/demos/personal_video_call.dart implements this pattern.

Group Call Layouts

The layout is automatically resolved based on participant count:

Participants	Layout
1-2	Full screen + PiP
3-4	2x2 grid
5-6	2x3 grid
7+	Speaker view (active speaker + thumbnail row)
Any + screen share	Screen share view + thumbnail row

"More" Bottom Sheet

The moreSheetBuilder callback lets you add custom actions to the "more" bottom sheet. The kit wraps your content with a handle bar, encryption label, and cancel button.

CallScreen(
  // ...
  moreSheetBuilder: (context, theme) => Container(
    margin: const EdgeInsets.symmetric(horizontal: 16),
    decoration: BoxDecoration(
      color: theme.buttonBackground,
      borderRadius: BorderRadius.circular(12),
    ),
    child: Column(
      children: [
        ListTile(
          title: Text('Share Screen', style: TextStyle(color: theme.textPrimary)),
          trailing: Icon(Icons.screen_share, color: theme.textPrimary),
          onTap: () {
            Navigator.pop(context);
            // your logic
          },
        ),
        ListTile(
          title: Text('Send Message', style: TextStyle(color: theme.textPrimary)),
          trailing: Icon(Icons.message, color: theme.textPrimary),
          onTap: () {
            Navigator.pop(context);
            // your logic
          },
        ),
      ],
    ),
  ),
)

Exported Widgets

These widgets are exported for standalone use if needed:

Widget	Description
`CallAvatar`	Circle avatar with network image or colored initials fallback
`ParticipantTile`	Single participant tile with video, overlays, and speaking border
`FloatingPipView`	Draggable picture-in-picture overlay that snaps to corners
`SpeakingIndicator`	Animated 3-bar sine-wave speaking indicator
`ScreenShareBanner`	Slide-in banner for screen sharing status
`ConnectionStateBanner`	Persistent "Connecting…"/"Reconnecting…" status banner
`MoreBottomSheet`	Bottom sheet with handle bar, encryption label, and cancel button
`ParticipantsPanel`	Draggable scrollable participant list with host actions
`SignalStrengthIcon`	4-bar signal strength indicator
`VideoSurface`	Opaque mounting surface for externally-provided video widgets

Exported Utilities

Utility	Description
`GroupCallLayoutResolver`	Resolves grid layout mode based on participant count
`PipSnapCalculator`	Resolves the PiP's anchor corner (`PipCorner`) and the offset for it

Requirements

Flutter SDK >= 3.22.0
Dart SDK ^3.4.0

License

See LICENSE file.

call_ui_kit

Screenshots

Features

Installation

Quick Start

Personal Audio Call

Personal Video Call

Group Video Call

Incoming / Outgoing Call

API Reference

CallScreen

Required Parameters

Optional Parameters

Optional Callbacks

CallParticipant

CallTheme

CallStrings

CallType

CallConnectionState

SignalStrength

Reconnection

Performance

Group Call Layouts

"More" Bottom Sheet

Exported Widgets

Exported Utilities

Requirements

License

Libraries

call_ui_kit package

call_ui_kit

Screenshots

Features

Installation

Quick Start

Personal Audio Call

Personal Video Call

Group Video Call

Screen Sharing

Incoming / Outgoing Call

API Reference

CallScreen

Required Parameters

Optional Parameters

Optional Callbacks

CallParticipant

CallTheme

CallStrings

CallType

CallConnectionState

SignalStrength

Reconnection

Performance

Group Call Layouts

"More" Bottom Sheet

Exported Widgets

Exported Utilities

Requirements

License

Libraries

call_ui_kit package