builder method

@override Widget builder(BuildContext context, ChatViewModel viewModel, Widget? child)

A function that builds the UI to be shown from the ViewModel - Required

viewModel is the ViewModel passed in and child is the staticChildBuilder result

Implementation

@override
Widget builder(
  BuildContext context,
  ChatViewModel viewModel,
  Widget? child,
) {
  return Scaffold(
    appBar: appBar ??
        AppBar(
          centerTitle: true,
          title: const Text("Firebase Realtime Individual Chat"),
        ),
    body: Stack(
      children: [
        ListView.builder(
            itemCount: viewModel.chatRooms.length,
            itemBuilder: (context, index) {
              ChatRoom chatRoom = viewModel.chatRooms[index];
              return InkWell(
                onTap: () {
                  UserModel? otherUser =
                      chatRoom.members["senderId"]?.userId == userData.userId
                          ? chatRoom.members["receiverId"]
                          : chatRoom.members["senderId"];
                  Navigator.push(
                    context,
                    MaterialPageRoute(
                      builder: (context) => ChatRoomView(
                        iconColor: iconColor,
                        textFieldBorderColor: textFieldBorderColor,
                        imageQuality: imageQuality,
                        defaultImage: defaultImage,
                        imageDownloadButton: imageDownloadButton,
                        ownerBubbleColor: ownerBubbleColor,
                        otherBubbleColor: otherBubbleColor,
                        senderMember: UserModel(
                          userId: userData.userId,
                          name: userData.name,
                          profile: userData.profile,
                        ),
                        receiverMember: UserModel(
                          userId: otherUser?.userId ?? "",
                          name: otherUser?.name ?? "",
                          profile: otherUser?.profile ?? "",
                        ),
                      ),
                    ),
                  );
                },
                child: Card(
                  margin:
                      const EdgeInsets.symmetric(vertical: 2, horizontal: 10),
                  child: ListTile(
                    leading: CircleAvatar(
                      backgroundImage: NetworkImage((viewModel
                                      .userData?.userId !=
                                  chatRoom.members["senderId"]?.userId
                              ? chatRoom.members["senderId"]?.profile
                              : chatRoom.members["receiverId"]?.profile) ??
                          "https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTUUfNCnMwMeh_5WuKXe55VTTVQcF1CN7Yb6Jw5TWYcngvaPF_z7yapb8o0PCoQMVv3UTs&usqp=CAU"),
                    ),
                    title: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          "${userData.userId != chatRoom.members["senderId"]?.userId ? chatRoom.members["senderId"]?.name : chatRoom.members["receiverId"]?.name}",
                          style: const TextStyle(
                              color: Colors.black54,
                              fontWeight: FontWeight.w600),
                        ),
                        Text(
                          maxLines: 1,
                          ((chatRoom.lastMessage?.text ?? "").isNotEmpty
                                  ? chatRoom.lastMessage?.text
                                  : (chatRoom.lastMessage?.url ?? "")
                                          .isNotEmpty
                                      ? chatRoom.lastMessage?.type
                                      : "")
                              .toString(),
                          overflow: TextOverflow.ellipsis,
                          style: const TextStyle(color: Colors.grey),
                        ),
                      ],
                    ),
                    trailing: Text(timeAgo(chatRoom.lastMessage!.createdOn)),
                  ),
                ),
              );
            }),
        if (viewModel.isBusy)
          Center(
            child: foundation.defaultTargetPlatform == TargetPlatform.iOS
                ? const CupertinoActivityIndicator()
                : const CircularProgressIndicator(),
          ),
      ],
    ),
  );
}