comfy_table/utils/formatting/
content_format.rs

1#[cfg(feature = "tty")]
2use crossterm::style::{style, Stylize};
3use unicode_segmentation::UnicodeSegmentation;
4use unicode_width::UnicodeWidthStr;
5
6use super::content_split::measure_text_width;
7use super::content_split::split_line;
8
9use crate::cell::Cell;
10use crate::row::Row;
11use crate::style::CellAlignment;
12#[cfg(feature = "tty")]
13use crate::style::{map_attribute, map_color};
14use crate::table::Table;
15use crate::utils::ColumnDisplayInfo;
16
17pub fn delimiter(cell: &Cell, info: &ColumnDisplayInfo, table: &Table) -> char {
18    // Determine, which delimiter should be used
19    if let Some(delimiter) = cell.delimiter {
20        delimiter
21    } else if let Some(delimiter) = info.delimiter {
22        delimiter
23    } else if let Some(delimiter) = table.delimiter {
24        delimiter
25    } else {
26        ' '
27    }
28}
29
30/// Returns the formatted content of the table.
31/// The content is organized in the following structure
32///
33/// tc stands for table content and represents the returned value
34/// ``` text
35///      column1          column2
36/// row1 tc[0][0][0]      tc[0][0][1] <-line1
37///      tc[0][1][0]      tc[0][1][1] <-line2
38///      tc[0][2][0]      tc[0][2][1] <-line3
39///
40/// row2 tc[1][0][0]      tc[1][0][1] <-line1
41///      tc[1][1][0]      tc[1][1][1] <-line2
42///      tc[1][2][0]      tc[1][2][1] <-line3
43/// ```
44///
45/// The strings for each row will be padded and aligned according to their respective column.
46pub fn format_content(table: &Table, display_info: &[ColumnDisplayInfo]) -> Vec<Vec<Vec<String>>> {
47    // The content of the whole table
48    let mut table_content = Vec::with_capacity(table.rows.len() + 1);
49
50    // Format table header if it exists
51    if let Some(header) = table.header() {
52        table_content.push(format_row(header, display_info, table));
53    }
54
55    for row in table.rows.iter() {
56        table_content.push(format_row(row, display_info, table));
57    }
58    table_content
59}
60
61pub fn format_row(
62    row: &Row,
63    display_infos: &[ColumnDisplayInfo],
64    table: &Table,
65) -> Vec<Vec<String>> {
66    // The content of this specific row
67    let mut temp_row_content = Vec::with_capacity(display_infos.len());
68
69    let mut cell_iter = row.cells.iter();
70    // Now iterate over all cells and handle them according to their alignment
71    for info in display_infos.iter() {
72        if info.is_hidden {
73            cell_iter.next();
74            continue;
75        }
76        // Each cell is divided into several lines divided by newline
77        // Every line that's too long will be split into multiple lines
78        let mut cell_lines = Vec::new();
79
80        // Check if the row has as many cells as the table has columns.
81        // If that's not the case, create a new cell with empty spaces.
82        let cell = if let Some(cell) = cell_iter.next() {
83            cell
84        } else {
85            cell_lines.push(" ".repeat(info.width().into()));
86            temp_row_content.push(cell_lines);
87            continue;
88        };
89
90        // The delimiter is configurable, determine which one should be used for this cell.
91        let delimiter = delimiter(cell, info, table);
92
93        // Iterate over each line and split it into multiple lines if necessary.
94        // Newlines added by the user will be preserved.
95        for line in cell.content.iter() {
96            if measure_text_width(line) > info.content_width.into() {
97                let mut parts = split_line(line, info, delimiter);
98                cell_lines.append(&mut parts);
99            } else {
100                cell_lines.push(line.into());
101            }
102        }
103
104        // Remove all unneeded lines of this cell, if the row's height is capped to a certain
105        // amount of lines and there're too many lines in this cell.
106        // This then truncates and inserts a '...' string at the end of the last line to indicate
107        // that the cell has been truncated.
108        if let Some(lines) = row.max_height {
109            if cell_lines.len() > lines {
110                // We already have to many lines. Cut off the surplus lines.
111                let _ = cell_lines.split_off(lines);
112
113                // Directly access the last line.
114                let last_line = cell_lines
115                    .get_mut(lines - 1)
116                    .expect("We know it's this long.");
117
118                // Truncate any ansi codes, as the following cutoff might break ansi code
119                // otherwise anyway. This could be handled smarter, but it's simple and just works.
120                #[cfg(feature = "custom_styling")]
121                {
122                    let stripped = console::strip_ansi_codes(last_line).to_string();
123                    *last_line = stripped;
124                }
125
126                let max_width: usize = info.content_width.into();
127                let indicator_width = table.truncation_indicator.width();
128
129                let mut truncate_at = 0;
130                // Start the accumulated_width with the indicator_width, which is the minimum width
131                // we may show anyway.
132                let mut accumulated_width = indicator_width;
133                let mut full_string_fits = false;
134
135                // Leave these print statements in here in case we ever have to debug this annoying
136                // stuff again.
137                //println!("\nSTART:");
138                //println!("\nMax width: {max_width}, Indicator width: {indicator_width}");
139                //println!("Full line hex: {last_line}");
140                //println!(
141                //    "Full line hex: {}",
142                //    last_line
143                //        .as_bytes()
144                //        .iter()
145                //        .map(|byte| format!("{byte:02x}"))
146                //        .collect::<Vec<String>>()
147                //        .join(", ")
148                //);
149
150                // Iterate through the UTF-8 graphemes.
151                // Check the `split_long_word` inline function docs to see why we're using
152                // graphemes.
153                // **Note:** The `index` here is the **byte** index. So we cannot just
154                //    String::truncate afterwards. We have to convert to a byte vector to perform
155                //    the truncation first.
156                let mut grapheme_iter = last_line.grapheme_indices(true).peekable();
157                while let Some((index, grapheme)) = grapheme_iter.next() {
158                    // Leave these print statements in here in case we ever have to debug this
159                    // annoying stuff again
160                    //println!(
161                    //    "Current index: {index}, Next grapheme: {grapheme} (width: {})",
162                    //    grapheme.width()
163                    //);
164                    //println!(
165                    //    "Next grapheme hex: {}",
166                    //    grapheme
167                    //        .as_bytes()
168                    //        .iter()
169                    //        .map(|byte| format!("{byte:02x}"))
170                    //        .collect::<Vec<String>>()
171                    //        .join(", ")
172                    //);
173
174                    // Immediately save where to truncate in case this grapheme doesn't fit.
175                    // The index is just before the current grapheme actually starts.
176                    truncate_at = index;
177                    // Check if the next grapheme would break the boundary of the allowed line
178                    // length.
179                    let new_width = accumulated_width + grapheme.width();
180                    //println!(
181                    //    "Next width: {new_width}/{max_width} ({accumulated_width} + {})",
182                    //    grapheme.width()
183                    //);
184                    if new_width > max_width {
185                        //println!(
186                        //    "Breaking: {:?}",
187                        //    accumulated_width + grapheme.width() > max_width
188                        //);
189                        break;
190                    }
191
192                    // The grapheme seems to fit. Save the index and check the next one.
193                    accumulated_width += grapheme.width();
194
195                    // This is a special case.
196                    // We reached the last char, meaning that full last line + the indicator fit.
197                    if grapheme_iter.peek().is_none() {
198                        full_string_fits = true
199                    }
200                }
201
202                // Only do any truncation logic if the line doesn't fit.
203                if !full_string_fits {
204                    // Truncate the string at the byte index just behind the last valid grapheme
205                    // and overwrite the last line with the new truncated string.
206                    let mut last_line_bytes = last_line.clone().into_bytes();
207                    last_line_bytes.truncate(truncate_at);
208                    let new_last_line = String::from_utf8(last_line_bytes)
209                        .expect("We cut at an exact char boundary");
210                    *last_line = new_last_line;
211                }
212
213                // Push the truncation indicator.
214                last_line.push_str(&table.truncation_indicator);
215            }
216        }
217
218        // Iterate over all generated lines of this cell and align them
219        let cell_lines = cell_lines
220            .iter()
221            .map(|line| align_line(table, info, cell, line.to_string()));
222
223        temp_row_content.push(cell_lines.collect());
224    }
225
226    // Right now, we have a different structure than desired.
227    // The content is organized by `row->cell->line`.
228    // We want to remove the cell from our datastructure, since this makes the next step a lot easier.
229    // In the end it should look like this: `row->lines->column`.
230    // To achieve this, we calculate the max amount of lines for the current row.
231    // Afterwards, we iterate over each cell and convert the current structure to the desired one.
232    // This step basically transforms this:
233    //  tc[0][0][0]     tc[0][1][0]
234    //  tc[0][0][1]     tc[0][1][1]
235    //  tc[0][0][2]     This part of the line is missing
236    //
237    // to this:
238    //  tc[0][0][0]     tc[0][0][1]
239    //  tc[0][1][0]     tc[0][1][1]
240    //  tc[0][2][0]     tc[0][2][1] <- Now filled with placeholder (spaces)
241    let max_lines = temp_row_content.iter().map(Vec::len).max().unwrap_or(0);
242    let mut row_content = Vec::with_capacity(max_lines * display_infos.len());
243
244    // Each column should have `max_lines` for this row.
245    // Cells content with fewer lines will simply be topped up with empty strings.
246    for index in 0..max_lines {
247        let mut line = Vec::with_capacity(display_infos.len());
248        let mut cell_iter = temp_row_content.iter();
249
250        for info in display_infos.iter() {
251            if info.is_hidden {
252                continue;
253            }
254            let cell = cell_iter.next().unwrap();
255            match cell.get(index) {
256                // The current cell has content for this line. Append it
257                Some(content) => line.push(content.clone()),
258                // The current cell doesn't have content for this line.
259                // Fill with a placeholder (empty spaces)
260                None => line.push(" ".repeat(info.width().into())),
261            }
262        }
263        row_content.push(line);
264    }
265
266    row_content
267}
268
269/// Apply the alignment for a column. Alignment can be either Left/Right/Center.
270/// In every case all lines will be exactly the same character length `info.width - padding long`
271/// This is needed, so we can simply insert it into the border frame later on.
272/// Padding is applied in this function as well.
273#[allow(unused_variables)]
274fn align_line(table: &Table, info: &ColumnDisplayInfo, cell: &Cell, mut line: String) -> String {
275    let content_width = info.content_width;
276    let remaining: usize = usize::from(content_width).saturating_sub(measure_text_width(&line));
277
278    // Apply the styling before aligning the line, if the user requests it.
279    // That way non-delimiter whitespaces won't have stuff like underlines.
280    #[cfg(feature = "tty")]
281    if table.should_style() && table.style_text_only {
282        line = style_line(line, cell);
283    }
284
285    // Determine the alignment of the column cells.
286    // Cell settings overwrite the columns Alignment settings.
287    // Default is Left
288    let alignment = if let Some(alignment) = cell.alignment {
289        alignment
290    } else if let Some(alignment) = info.cell_alignment {
291        alignment
292    } else {
293        CellAlignment::Left
294    };
295
296    // Apply left/right/both side padding depending on the alignment of the column
297    match alignment {
298        CellAlignment::Left => {
299            line += &" ".repeat(remaining);
300        }
301        CellAlignment::Right => {
302            line = " ".repeat(remaining) + &line;
303        }
304        CellAlignment::Center => {
305            let left_padding = (remaining as f32 / 2f32).ceil() as usize;
306            let right_padding = (remaining as f32 / 2f32).floor() as usize;
307            line = " ".repeat(left_padding) + &line + &" ".repeat(right_padding);
308        }
309    }
310
311    line = pad_line(&line, info);
312
313    #[cfg(feature = "tty")]
314    if table.should_style() && !table.style_text_only {
315        return style_line(line, cell);
316    }
317
318    line
319}
320
321/// Apply the column's padding to this line
322fn pad_line(line: &str, info: &ColumnDisplayInfo) -> String {
323    let mut padded_line = String::new();
324
325    padded_line += &" ".repeat(info.padding.0.into());
326    padded_line += line;
327    padded_line += &" ".repeat(info.padding.1.into());
328
329    padded_line
330}
331
332#[cfg(feature = "tty")]
333fn style_line(line: String, cell: &Cell) -> String {
334    // Just return the line, if there's no need to style.
335    if cell.fg.is_none() && cell.bg.is_none() && cell.attributes.is_empty() {
336        return line;
337    }
338
339    let mut content = style(line);
340
341    // Apply text color
342    if let Some(color) = cell.fg {
343        content = content.with(map_color(color));
344    }
345
346    // Apply background color
347    if let Some(color) = cell.bg {
348        content = content.on(map_color(color));
349    }
350
351    for attribute in cell.attributes.iter() {
352        content = content.attribute(map_attribute(*attribute));
353    }
354
355    content.to_string()
356}