cosmic/widget/text_input/
value.rs

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
// Copyright 2019 H�ctor Ram�n, Iced contributors
// Copyright 2023 System76 <info@system76.com>
// SPDX-License-Identifier: MIT

use unicode_segmentation::UnicodeSegmentation;

/// The value of a [`TextInput`].
///
/// [`TextInput`]: crate::widget::TextInput
// TODO: Reduce allocations, cache results (?)
#[derive(Debug, Clone)]
pub struct Value {
    graphemes: Vec<String>,
}

impl Value {
    /// Creates a new [`Value`] from a string slice.
    pub fn new(string: &str) -> Self {
        let graphemes = UnicodeSegmentation::graphemes(string, true)
            .map(String::from)
            .collect();

        Self { graphemes }
    }

    /// Returns whether the [`Value`] is empty or not.
    ///
    /// A [`Value`] is empty when it contains no graphemes.
    #[must_use]
    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Returns the total amount of graphemes in the [`Value`].
    #[must_use]
    pub fn len(&self) -> usize {
        self.graphemes.len()
    }

    /// Returns the position of the previous start of a word from the given
    /// grapheme `index`.
    #[must_use]
    pub fn previous_start_of_word(&self, index: usize) -> usize {
        let previous_string = &self.graphemes[..index.min(self.graphemes.len())].concat();

        UnicodeSegmentation::split_word_bound_indices(previous_string as &str)
            .filter(|(_, word)| !word.trim_start().is_empty())
            .next_back()
            .map_or(0, |(i, previous_word)| {
                index
                    - UnicodeSegmentation::graphemes(previous_word, true).count()
                    - UnicodeSegmentation::graphemes(
                        &previous_string[i + previous_word.len()..] as &str,
                        true,
                    )
                    .count()
            })
    }

    /// Returns the position of the next end of a word from the given grapheme
    /// `index`.
    #[must_use]
    pub fn next_end_of_word(&self, index: usize) -> usize {
        let next_string = &self.graphemes[index..].concat();

        UnicodeSegmentation::split_word_bound_indices(next_string as &str)
            .find(|(_, word)| !word.trim_start().is_empty())
            .map_or(self.len(), |(i, next_word)| {
                index
                    + UnicodeSegmentation::graphemes(next_word, true).count()
                    + UnicodeSegmentation::graphemes(&next_string[..i] as &str, true).count()
            })
    }

    /// Returns a new [`Value`] containing the graphemes from `start` until the
    /// given `end`.
    #[must_use]
    pub fn select(&self, start: usize, end: usize) -> Self {
        let graphemes = self.graphemes[start.min(self.len())..end.min(self.len())].to_vec();

        Self { graphemes }
    }

    /// Returns a new [`Value`] containing the graphemes until the given
    /// `index`.
    #[must_use]
    pub fn until(&self, index: usize) -> Self {
        let graphemes = self.graphemes[..index.min(self.len())].to_vec();

        Self { graphemes }
    }

    /// Inserts a new `char` at the given grapheme `index`.
    pub fn insert(&mut self, index: usize, c: char) {
        self.graphemes.insert(index, c.to_string());

        self.graphemes = UnicodeSegmentation::graphemes(&self.to_string() as &str, true)
            .map(String::from)
            .collect();
    }

    /// Inserts a bunch of graphemes at the given grapheme `index`.
    pub fn insert_many(&mut self, index: usize, mut value: Value) {
        let _ = self
            .graphemes
            .splice(index..index, value.graphemes.drain(..));
    }

    /// Removes the grapheme at the given `index`.
    pub fn remove(&mut self, index: usize) {
        let _ = self.graphemes.remove(index);
    }

    /// Removes the graphemes from `start` to `end`.
    pub fn remove_many(&mut self, start: usize, end: usize) {
        let _ = self.graphemes.splice(start..end, std::iter::empty());
    }

    /// Returns a new [`Value`] with all its graphemes replaced with the
    /// dot ('•') character.
    #[must_use]
    pub fn secure(&self) -> Self {
        Self {
            graphemes: std::iter::repeat(String::from("•"))
                .take(self.graphemes.len())
                .collect(),
        }
    }
}

impl ToString for Value {
    fn to_string(&self) -> String {
        self.graphemes.concat()
    }
}