QR, barcodes & charts¶

All of these emit pure vector geometry — no rasterisation, no external dependencies — and render identically on every platform.

QR codes¶

qrCode(data) is a full ISO 18004 Model 2 generator (versions 1–40, all four EC levels, Reed-Solomon, all 8 masks); the smallest version that fits the payload is chosen automatically:

qrCode("https://github.com/conamobiledev/PdfKmp", size = 110.dp)

qrCode(
    data = "https://github.com/conamobiledev/PdfKmp",
    size = 110.dp,
    errorCorrection = QrErrorCorrection.H,   // L / M (default) / Q / H
    color = PdfColor(0.1f, 0.2f, 0.5f),      // brand colour; keep strong contrast
)

Barcodes — Code 128, EAN-13, UPC-A¶

barcode(data, symbology = …) draws a 1D barcode as pure vector bars. Pick the encoding with the symbology parameter (BarcodeSymbology, default Code128). The human-readable caption is not drawn automatically — add a text(data) below:

column(spacing = 4.dp) {
    barcode("INV-2026-00042", height = 50.dp)   // Code 128 — the default
    text("INV-2026-00042") { fontSize = 10.sp }
}

column(spacing = 4.dp) {
    // 12 digits → the EAN-13 check digit is computed for you (13 → verified).
    barcode("400638133393", symbology = BarcodeSymbology.Ean13, height = 50.dp)
    text("EAN-13 4006381333931") { fontSize = 10.sp }
}

column(spacing = 4.dp) {
    // 11 digits → the UPC-A check digit is computed (12 → verified).
    barcode("036000291452", symbology = BarcodeSymbology.UpcA, height = 50.dp)
    text("UPC-A 036000291452") { fontSize = 10.sp }
}

`BarcodeSymbology`	Payload	Notes
`Code128` (default)	Printable ASCII 32–126	Digit runs compress via code set C; mod-103 checksum appended for you.
`Ean13`	12 digits (check computed) or 13 (check verified)	Retail product codes.
`UpcA`	11 digits (check computed) or 12 (check verified)	Rendered as the equivalent EAN-13 symbol.

Invalid input for the chosen symbology throws IllegalArgumentException at build time.

Data Matrix (ECC 200)¶

dataMatrix(data) draws a 2D Data Matrix (ECC 200) symbol as crisp vector squares. ASCII encodation only — bytes above 127 are rejected at build time — and the smallest fitting square symbol (10×10 … 52×52) is chosen automatically:

dataMatrix("PdfKmp", size = 90.dp)
dataMatrix("SN-2026-00042", size = 90.dp, color = PdfColor(0.1f, 0.2f, 0.5f))

PDF417 is not offered

PdfKmp ships QR, Code 128, EAN-13/UPC-A, and Data Matrix — but not PDF417. Its 2,787-entry cluster tables can't be reproduced reliably without the spec at hand, and a wrong table would render unscannable symbols, so it was deliberately left out rather than shipped subtly broken.

Quiet zone

Leave a quiet zone around any symbol — page padding or a padded container usually suffices.

Charts¶

Bar, line, pie, and donut charts are extension functions on any container scope, composed entirely from the public DSL (freeDraw, row, text) so every glyph and slice stays vector. Bars / pie / donut take a List<ChartSeries> (label + value + colour).

val series = listOf(
    ChartSeries("Q1", 10f, PdfColor.Red),
    ChartSeries("Q2", 20f, PdfColor.Green),
    ChartSeries("Q3", 15f, PdfColor.Blue),
)

barChart(series, width = 300.dp, height = 160.dp)          // value captions + label row included
lineChart(listOf(3f, 7f, 4f, 9f, 6f), width = 300.dp, height = 120.dp, fillUnderLine = true)
pieChart(series, diameter = 160.dp)                         // swatch + percentage legend by default
donutChart(series, diameter = 160.dp, holeRatio = 0.55f)

Signatures (defaults shown):

barChart(
    series: List<ChartSeries>, width: Dp, height: Dp,
    showValues: Boolean = true, showAxis: Boolean = true,
    gridLines: Int = 0, axisColor: PdfColor = PdfColor.Gray, gridColor: PdfColor = PdfColor.LightGray,
)

stackedBarChart(
    groups: List<StackedBarGroup>, width: Dp, height: Dp,
    showAxis: Boolean = true, gridLines: Int = 0, showLegend: Boolean = true,
    axisColor: PdfColor = PdfColor.Gray, gridColor: PdfColor = PdfColor.LightGray,
)

lineChart(
    points: List<Float>, width: Dp, height: Dp,
    color: PdfColor = PdfColor.Blue, strokeWidth: Float = 2f, fillUnderLine: Boolean = false,
    gridLines: Int = 0, axisColor: PdfColor = PdfColor.Gray, gridColor: PdfColor = PdfColor.LightGray,
)

// Multi-series overload — one LineSeries per line, with a legend:
lineChart(
    series: List<LineSeries>, width: Dp, height: Dp,
    strokeWidth: Float = 2f, gridLines: Int = 0, showLegend: Boolean = true,
    axisColor: PdfColor = PdfColor.Gray, gridColor: PdfColor = PdfColor.LightGray,
)

pieChart(slices: List<ChartSeries>, diameter: Dp, showLegend: Boolean = true)
donutChart(slices: List<ChartSeries>, diameter: Dp, holeRatio: Float = 0.55f, showLegend: Boolean = true)

showAxis toggles (and axisColor colours) the always-present baseline + value axis on bar / stacked-bar / line charts; gridLines (0 = none) draws that many evenly-spaced reference lines behind the data in gridColor.

Empty / degenerate data draws nothing

Empty data, all-zero, or all-negative values draw nothing rather than throwing. A lineChart needs at least two points.

No bundled chart sample

Charts have no dedicated Samples.* document yet — the snippets above are the canonical, copy-pasteable examples. (Samples.barcodes() covers QR + Code 128 + EAN-13/UPC-A + Data Matrix; the design samples exercise freeDraw, which charts build on.)