Styling topic

Everything that controls how a cell looks: CellStyle gathers font, colour, fill, borders, and alignment; ExcelColor names a colour; Border a cell edge; and GradientFill a gradient. Number formatting lives in its own category (see NumFormat).

Apply a style when writing a cell, or set it on an existing cell:

sheet.updateCell(
  CellIndex.indexByString('A1'),
  TextCellValue('Header'),
  cellStyle: CellStyle(
    bold: true,
    italic: true,
    fontSize: 14,
    fontColorHex: ExcelColor.white,
    backgroundColorHex: ExcelColor.fromHexString('#21A366'),
    horizontalAlign: HorizontalAlign.Center,
    verticalAlign: VerticalAlign.Center,
    textWrapping: TextWrapping.WrapText,
  ),
);

Colours can be a literal hex, or a theme/indexed reference that round-trips as such:

ExcelColor.fromHexString('#2962FF');        // literal RGB
ExcelColor.theme(ThemeColor.accent1, tint: -0.2); // darker accent 1
ExcelColor.indexed(10);                     // legacy palette index

Borders are per edge; each takes a BorderStyle and an optional colour:

sheet.cell(CellIndex.indexByString('A1')).cellStyle = CellStyle(
  leftBorder: Border(borderStyle: BorderStyle.Thin),
  rightBorder: Border(borderStyle: BorderStyle.Thin),
  topBorder: Border(borderStyle: BorderStyle.Medium),
  bottomBorder:
      Border(borderStyle: BorderStyle.Medium, borderColorHex: ExcelColor.red),
);

Fills can be solid (backgroundColorHex), a pattern (CellStyle.fillPattern with FillPatternType), or a gradient:

sheet.cell(CellIndex.indexByString('A2')).cellStyle = CellStyle(
  gradientFill: GradientFill.linear(degree: 90, stops: [
    GradientStop(0, ExcelColor.fromHexString('#2962FF')),
    GradientStop(1, ExcelColor.white),
  ]),
);

Classes

Border Styling
Represents a border on one side of a cell.
CellStyle Styling
Styling class for cells.
ExcelColor Styling
Represents a color value for use in cell styling.
GradientFill Styling
A gradient cell fill, a smooth blend between two or more colour stops.
GradientStop Styling
One colour stop of a GradientFill: color placed at position along the gradient (0.0 = start, 1.0 = end). A gradient needs at least two stops.

Enums

BorderStyle Styling
Available border line styles in Excel.
ColorType Styling
Color type category.
FillPatternType Styling
Cell fill pattern. solid fills the cell with a single colour (the cell style's backgroundColor); the other patterns draw a hatch/shade using the backgroundColor as the pattern colour over an optional fillBackgroundColor.
FontFamily Styling
Available font families.
FontScheme Styling
Font scheme setting.
GradientType Styling
The geometry of a GradientFill.
HorizontalAlign Styling
Horizontal alignment of cell content.
TextWrapping Styling
Text wrapping mode for cells.
ThemeColor Styling
The twelve document-theme color slots, in the order Excel indexes them in styles.xml (theme="N"). Use with ExcelColor.theme to author a color that follows the workbook's theme.
Underline Styling
Text underline style.
VerticalAlign Styling
Vertical alignment of cell content.