Barcodes and QR codes

June 10, 2026 · View on GitHub

A barcode is a first-class canonical node: addBarcode lives on AbstractFlowBuilder, so codes drop into pageFlow, module, and section containers — and combine with rows, cards, layer stacks, and tables — like any other block. The builder is BarcodeBuilder; the result is a BarcodeNode carrying DocumentBarcodeOptions.

Quick start: a QR code

document.pageFlow()
        .addBarcode(barcode -> barcode
                .name("RepoQr")
                .qrCode()
                .data("https://github.com/DemchaAV/GraphCompose")
                .size(150, 150))
        .build();

data(...) sets the encoded content; size(width, height) (or the separate width(...) / height(...) setters) fixes the drawn box in points.

Symbologies

Five formats have fluent shortcuts — each is a single call:

barcode.qrCode();      // QR code (2D)
barcode.code128();     // Code 128 — invoice numbers, logistics ids
barcode.code39();      // Code 39 — alphanumeric asset tags
barcode.ean13();       // EAN-13 — 13-digit retail
barcode.ean8();        // EAN-8 — 8-digit compact retail

The full DocumentBarcodeType enum also covers UPC_A, PDF_417, and DATA_MATRIX — select those through the generic setter:

import com.demcha.compose.document.node.DocumentBarcodeType;

barcode.type(DocumentBarcodeType.DATA_MATRIX)
        .data("LOT-2026-04-001");

Brand tinting and quiet zone

Foreground and background take any DocumentColor, so a QR code can match the document palette instead of shipping in black-on-white. quietZone(n) adds the symbology's blank margin, measured in barcode modules:

import com.demcha.compose.document.style.DocumentColor;

section.addBarcode(barcode -> barcode
        .qrCode()
        .data("https://demcha.io/graphcompose")
        .foreground(DocumentColor.rgb(20, 80, 95))      // brand teal
        .background(DocumentColor.rgb(232, 244, 245))   // soft tint
        .quietZone(2)
        .size(150, 150));

Keep the foreground much darker than the background — scanners need the contrast.

Clickable codes

A barcode accepts the same link and bookmark metadata as paragraphs and images, so the printed QR can double as a clickable area in the PDF viewer:

import com.demcha.compose.document.node.DocumentLinkOptions;

barcode.qrCode()
        .data("https://github.com/DemchaAV/GraphCompose")
        .link(new DocumentLinkOptions("https://github.com/DemchaAV/GraphCompose"))
        .size(150, 150);

Centring a barcode in a card

Barcodes have fixed sizes, so inside a card they sit at the leading edge by default. Wrap the built node in a shape container sized to the card's content width with CENTER alignment — OVERFLOW_VISIBLE skips clipping (see the shape-as-container recipe):

import com.demcha.compose.document.dsl.BarcodeBuilder;
import com.demcha.compose.document.node.BarcodeNode;
import com.demcha.compose.document.style.ClipPolicy;

BarcodeNode code = new BarcodeBuilder()
        .ean13()
        .data("5901234123457")
        .size(190, 90)
        .build();

section
        .softPanel(DocumentColor.WHITE, 8, 14)
        .addContainer(card -> card
                .name("Ean13_Center")
                .rectangle(228, code.height())   // card content width
                .clipPolicy(ClipPolicy.OVERFLOW_VISIBLE)
                .center(code));

The container's rectangle spans the available slot; the barcode lands at the visual midline regardless of its natural aspect ratio.

Quick start: a QR code

Symbologies

Brand tinting and quiet zone

Clickable codes

Centring a barcode in a card

See also