MessageListView_Body.swift

GeometryReader { geometry in
    ForEach(self.messages) { message in
        MessageView(message: message)
            .padding(.horizontal, 8)
            .padding(EdgeInsets(
                top: 0,
                leading: message.sender == .me ? geometry.size.width * 0.5 : 0 ,
                bottom: 0,
                trailing: message.sender == .me ? 0 : geometry.size.width * 0.5))
    }
}