You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: viewer.rs
    path of file: ./repos/diem/language/tools/move-bytecode-viewer/src
    
    the code of the file until where you have to start completion: // Copyright (c) The Diem Core Contributors
// SPDX-License-Identifier: Apache-2.0

#![forbid(unsafe_code)]
use crate::{
    interfaces::{LeftScreen, RightScreen},
    tui::{
        text_builder::TextBuilder,
        tui_interface::{TUIInterface, TUIOutput},
    },
};
use tui::{
    style::{Color, Style},
    text::Spans,
};

#[derive(Debug, Clone)]
pub struct Viewer<BytecodeViewer: LeftScreen, SourceViewer: RightScreen<BytecodeViewer>> {
    bytecode_text: Vec<String>,
    source_viewer: SourceViewer,
    bytecode_viewer: BytecodeViewer,
}

impl<BytecodeViewer: LeftScreen, SourceViewer: RightScreen<BytecodeViewer>>
    Viewer<BytecodeViewer, SourceViewer>
{
    pub fn new(source_viewer: SourceViewer, bytecode_viewer: BytecodeViewer) -> Self {
        Self {
         
    
    fn on_redraw(&mut self, line_number: u16, column_number: u16) -> TUIOutput {
        // Highlight style
        let style: Style = Style::default().bg(Color::Red);
        let report = match self
            .bytecode_viewer
            .get_source_index_for_line(line_number as usize, column_number as usize)
        {
            None => {
                let mut builder = TextBuilder::new();
                builder.add(self.source_viewer.backing_string(), Style::default());
                builder.finish()
            }
            Some(info) => {
                let source_context = self.source_viewer.source_for_code_location(info).unwrap();

                let mut builder = TextBuilder::new();
                builder.add(source_context.left, Style::default());
                builder.add(source_context.highlight, style);
                builder.add(source_context.remainder, Style::default());
                builder.finish()
            }
        };

        TUIOutput {
            left_screen: self
                .bytecode_text
                .iter()
                .map(|x| Spans::from(x.clone()))
                .collect(),
            right_screen: report,
        }
    }