aboutsummaryrefslogtreecommitdiff
path: root/src/backends/dialog.rs
blob: 939b8f37c88e6a34a55a24d10ec416cb2cdf0554 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
// Copyright (C) 2019 Robin Krahl <robin.krahl@ireas.org>
// SPDX-License-Identifier: MIT

use std::process;

use crate::{Choice, Error, Input, Message, Password, Question, Result};

/// The `dialog` backend.
///
/// This backend uses the external `dialog` program (not to be confused with this crate also called
/// `dialog`) to display text-based dialog boxes in the terminal.
#[derive(Debug)]
pub struct Dialog {
    backtitle: Option<String>,
    width: String,
    height: String,
}

impl Dialog {
    /// Creates a new `Dialog` instance without configuration.
    pub fn new() -> Dialog {
        Dialog {
            backtitle: None,
            height: "0".to_string(),
            width: "0".to_string(),
        }
    }

    /// Sets the backtitle for the dialog boxes.
    ///
    /// The backtitle is displayed on the backdrop, at the top of the screen.
    pub fn set_backtitle(&mut self, backtitle: impl Into<String>) {
        self.backtitle = Some(backtitle.into());
    }

    /// Sets the height of the dialog boxes.
    ///
    /// The height is given in characters.  The actual height of the dialog box might be higher
    /// than the given height if the content would not fit otherwise.  The default height is zero.
    pub fn set_height(&mut self, height: u32) {
        self.height = height.to_string();
    }

    /// Sets the width of the dialog boxes.
    ///
    /// The width is given in characters.  The actual width of the dialog box might be higher than
    /// the given width if the content would not fit otherwise.  The default width is zero.
    pub fn set_width(&mut self, width: u32) {
        self.width = width.to_string();
    }

    fn execute(
        &self,
        args: Vec<&str>,
        post_args: Vec<&str>,
        title: &Option<String>,
    ) -> Result<process::Output> {
        let mut command = process::Command::new("dialog");
        command.stdin(process::Stdio::inherit());
        command.stdout(process::Stdio::inherit());

        if let Some(ref backtitle) = self.backtitle {
            command.arg("--backtitle");
            command.arg(backtitle);
        }
        if let Some(ref title) = title {
            command.arg("--title");
            command.arg(title);
        }

        command.args(args);
        command.arg(&self.height);
        command.arg(&self.width);
        command.args(post_args);

        command.output().map_err(Error::IoError)
    }
}

fn require_success(status: process::ExitStatus) -> Result<()> {
    if status.success() {
        Ok(())
    } else {
        Err(Error::from(("dialog", status)))
    }
}

fn get_choice(status: process::ExitStatus) -> Result<Choice> {
    if let Some(code) = status.code() {
        match code {
            0 => Ok(Choice::Yes),
            1 => Ok(Choice::No),
            255 => Ok(Choice::Cancel),
            _ => Err(Error::from(("dialog", status))),
        }
    } else {
        Err(Error::from(("dialog", status)))
    }
}

fn get_stderr(output: process::Output) -> Result<Option<String>> {
    if output.status.success() {
        String::from_utf8(output.stderr)
            .map(|s| Some(s))
            .map_err(|err| Error::from(err))
    } else {
        if let Some(code) = output.status.code() {
            match code {
                0 => Ok(None),
                1 => Ok(None),
                255 => Ok(None),
                _ => Err(Error::from(("dialog", output.status))),
            }
        } else {
            Err(Error::from(("dialog", output.status)))
        }
    }
}

impl super::Backend for Dialog {
    fn show_input(&self, input: &Input) -> Result<Option<String>> {
        let args = vec!["--inputbox", &input.text];
        let mut post_args: Vec<&str> = Vec::new();
        if let Some(ref default) = input.default {
            post_args.push(default);
        }
        self.execute(args, post_args, &input.title)
            .and_then(get_stderr)
    }

    fn show_message(&self, message: &Message) -> Result<()> {
        let args = vec!["--msgbox", &message.text];
        self.execute(args, vec![], &message.title)
            .and_then(|output| require_success(output.status))
            .map(|_| ())
    }

    fn show_password(&self, password: &Password) -> Result<Option<String>> {
        let args = vec!["--passwordbox", &password.text];
        self.execute(args, vec![], &password.title)
            .and_then(get_stderr)
    }

    fn show_question(&self, question: &Question) -> Result<Choice> {
        let args = vec!["--yesno", &question.text];
        self.execute(args, vec![], &question.title)
            .and_then(|output| get_choice(output.status))
    }
}