Overview
CellFormat controls how raw cell values are displayed. It is purely visual —
the underlying data is not modified. Set it on ColumnDef::format:
col.format = Some(CellFormat::Number {
decimal_places: 2,
thousands_sep: Some(' '),
decimal_sep: '.',
});
Number
CellFormat::Number {
decimal_places: u8, // digits after decimal
thousands_sep: Option<char>, // e.g. Some(' ') or Some(',')
decimal_sep: char, // e.g. '.' or ','
}
Percent
CellFormat::Percent {
decimal_places: u8,
}
Multiplies by 100 and appends %:
Currency
CellFormat::Currency {
symbol: String, // e.g. "$" or "€"
decimal_places: u8,
thousands_sep: Option<char>,
symbol_after: bool, // true → "42.50 €", false → "$42.50"
}
Boolean
CellFormat::Boolean {
true_label: String, // e.g. "✓" or "Yes"
false_label: String, // e.g. "✗" or "No"
}
Truthy values: "true", "1", "yes" (case-insensitive). Everything
else is falsy. Displayed centered.
Image
CellFormat::Image {
base_url: Option<String>, // URL prefix (None = raw is full URL)
border_radius: f64, // corner radius in px
padding: f64, // padding inside the cell
}
Renders the cell value as an image. The final URL is base_url + raw_value.
ImageText
CellFormat::ImageText {
base_url: String, // e.g. "https://flagcdn.com/w40/"
suffix: String, // e.g. ".png"
image_size: f64, // square image size in px
border_radius: f64,
gap: f64, // gap between image and text
}
Raw value format: "KEY Label" — first token is the image key (lowercased
for the URL), rest is the display text.
Example: "FR France" → image URL https://flagcdn.com/w40/fr.png + text "France"
Custom
CellFormat::Custom(Rc::new(|raw: &str| FormattedCell {
text: raw.to_uppercase(),
bold: true,
color: Some([255, 0, 0, 255]), // red
..Default::default()
}))
Full control over text, alignment, bold, and color via a callback.
All formats produce a FormattedCell:
pub struct FormattedCell {
pub text: String,
pub align: Option<CellAlign>, // Left, Center, Right
pub bold: bool,
pub color: Option<[u8; 4]>, // RGBA override
}
Fallback behavior
If the raw value cannot be parsed (e.g. "abc" for a Number format), the
raw value is displayed as-is with no formatting applied.
