component DeltasList {
    in property <string> delta;
    VerticalBox {
        Text {
            vertical-stretch: 0;
            text: "change";
        }

        ScrollView {
            vertical-stretch: 1;
            viewport-width <=> text.width;
            viewport-height <=> text.height;
            text := Text {
                width: 100%;
                text: delta;
            }
        }
    }
}

            preferred-width: 500px;

            // preferred-width: 400px;

    preferred-width: 960px;
    preferred-height: 720px;

    in-out property <string> delta <=> deltas.delta;

    callback request-change-delta(string);

                if log.selected >= 0 {
                    root.request-change-delta(changes_log[log.selected].hash)
                } else {
                    delta = "";
                }

                horizontal-stretch: 0;

            log := Changelog { }

            log := Changelog {
                horizontal-stretch: 2;
                selection-changed => {
                    if log.selected >= 0 {
                        root.request-change-delta(changes_log[log.selected].hash)
                    } else {
                        delta = "";
                    }
                }
            }
            deltas := DeltasList {
                horizontal-stretch: 3;
            }

        }
    });
    ui.on_request_change_delta({
        let ui_handle = ui.as_weak();
        move |change_hash: SharedString| {
            let change_hash = change_hash.as_str();
            let ui = ui_handle.unwrap();
            let exe_path_string = ui.get_exe_path();
            let exe_path = Path::new(exe_path_string.as_str());
            let repo_path_string = ui.get_repo_path();
            let repo_path = Path::new(repo_path_string.as_str());
            let change_output = cmds::change(exe_path, repo_path, change_hash);
            let delta = match change_output {
                Ok(delta) => delta,
                Err(e) => {
                    println!("{:?}", e);
                    return;
                }
            };
            ui.set_delta((&String::from(delta)[..]).into());

}
pub fn change(exe: &std::path::Path, repo: &std::path::Path, hash: &str) -> Result<String, Error> {
    let mut cmd = Command::new(exe);
    let cmd = cmd
        .arg("change")
        .arg("--no-prompt")
        .arg("--repository")
        .arg(repo)
        .arg(hash);
    let output = cmd.output()?;
    check_exit_status(cmd, output.status)?;
    // TODO this will fail when diffing binary data
    Ok(String::from_utf8(output.stdout)?)

///////////////////////////////////////////////////////////////////////////////
// copied from https://users.rust-lang.org/t/best-error-handing-practices-when-using-std-command/42259/7

// end copy
///////////////////////////////////////////////////////////////////////////////