How to create a table cell with text of different color?

[JSchoeck]

How is it possible to create a table cell with text that has different color?

Only one style can be applied to a single cell, so it seems to not be possible.
ANSI escape characters can format text "inline", but are unfortunately not supported (yet?).

Any hints or opinions about this?

I looked at the implementation of cells in the code and am wondering where it could be implemented.
Copilot had a suggestion, which amazingly even does work, almost correctly:

import re
from typing import Literal
from fpdf import FPDF

class AnsiFPDF(FPDF):
    def __init__(self):
        super().__init__()
        self.ansi_escape = re.compile(r"\x1B\[[0-?]*[ -/]*[@-~]")

    def set_ansi_text_color(self, code: str) -> None:
        if code == "\033[90m":
            self.set_text_color(128, 128, 128)  # Grey
        elif code == "\033[0m":
            self.set_text_color(0, 0, 0)  # Reset to black

    def cell_with_ansi(
        self,
        w: float,
        h: float = 0,
        txt: str = "",
        border: bool | str | Literal[0, 1] = 0,
        align: str = "",
        fill: bool = False,
        link: str = "",
        center: bool = False,
    ) -> None:
        parts = self.ansi_escape.split(txt)
        matches = self.ansi_escape.findall(txt)

        x, y = self.get_x(), self.get_y()
        for i, part in enumerate(parts):
            if i < len(matches):
                self.set_ansi_text_color(matches[i])
            self.set_xy(x, y)
            super().cell(w, h, text=part, border=border, align=align, fill=fill, link=link, center=center)
            x += self.get_string_width(part)

# Usage example
if __name__ == "__main__":
    pdf = AnsiFPDF()
    pdf.add_page()
    pdf.set_font("Arial", size=12)
    pdf.cell_with_ansi(0, 10, "Normal text \033[90mGrey text\033[0m Normal text")
    pdf.output("example.pdf")

Could this be used here in FPDF2's table method _render_table_cell? It looks like replacing multi_cell with an adapted method should do the trick.

with self._fpdf.use_font_face(style):
    page_break_text, cell_height = self._fpdf.multi_cell(

Actually, diving one level deeper, I think _render_styled_text_line needs to be adapted, as it is passed the fragments of the text. This would need to be parsed for the escape characters. Is the text color finally applied here?

for i, frag in enumerate(fragments):
    if frag.graphics_state["text_color"] != last_used_color:
        # allow to change color within the line of text.
        last_used_color = frag.graphics_state["text_color"]
        sl.append(last_used_color.serialize().lower())
        fill_color_changed = True

Any thoughts? It would be an elegant way to make working with tables more flexible, in my opinion.

[Lucas-C]

Hi @JSchoeck

How is it possible to create a table cell with text that has different color?

Sure, you can even find examples of that in our documentation:

• example to set table headings text color: https://py-pdf.github.io/fpdf2/Tables.html#style-table-headings
• example to set text color in a single cell: https://py-pdf.github.io/fpdf2/Tables.html#setting-cell-padding

A style= parameter can also be specified at the row level.

[JSchoeck]

Thanks for you answer. Using a single color is easy, yes. However, I need to have different colors. i.e. a single cell with green, black, and red words.

[Lucas-C]

Oh alright, I didn't quite understand what you were trying to achieve, sorry 😅

Support for ANSI escape characters, is an interesting idea,
and yes it would allow to color fragments of text in a single cell in different shades.

And yes, it should be implemented at the FPDF._render_styled_text_line() level,
but also beforehand in fpdf.line_break when parsing lines into TextLine & Fragment objects.

A Fragment already has a .graphics_state attribute that contains its text_color.

Is this something that you would be interested on working on @JSchoeck? 🙂

[JSchoeck]

Yeah, I think so. Would a PR be welcome?

[Lucas-C]

Yes, very welcome! 🙂