Print Preview

Two ways to preview the same document: an HTML paper view sized in real millimetres (what window.print() sends to your printer) and the PDF view generated on the server. Change any setting and both update.

Document The HTML paper view is available for invoices; every document has the PDF view. Page setup preset

Paper size Orientation Watermark Zoom 80%

Download PDF

Tip: the browser's print dialog also offers "Save as PDF" - a quick way to compare the HTML print with the server PDF.

Northwind Print Co., Ltd.

88 Rama VI Road, Ratchathewi, Bangkok 10400

Tax ID 0105559999999

INVOICE

INV-202610-005
DRAFT

BILL TO

Green Valley International School
300 Moo 5, Nong Prue, Bang Lamung, Chon Buri 20150

Issue date21 Oct 2026

Due date20 Nov 2026

Amount due8,448.72

#	Description	Qty	Unit price	Amount
1	Thermal Labels 50 x 30 mm (1,000)	12	250.00	3,000.00
2	Price Tag Labels (10 rolls)	11	160.00	1,760.00
3	Kraft Mailer Box S	6	12.00	72.00
4	Price Tag Labels (10 rolls)	10	160.00	1,600.00
5	Binder Clips Assorted (box)	11	120.00	1,320.00
6	Kraft Mailer Box S	12	12.00	144.00

Subtotal	7,896.00
VAT 7%	552.72
Total (THB)	8,448.72

How it works

HTML paper view - the page is a <div> sized in real mm. CSS @page { size: 210mm 297mm; margin: 0 } sets the paper for the print dialog, and @media print in app.css hides the sidebar and buttons.
PDF view - the iframe loads /doc/view?key=invoice:5&preset=1... (HomeController.view). The response header Content-Disposition: inline makes the browser show it; attachment downloads it.
Print PDF calls iframe.contentWindow.print() - the browser's PDF viewer prints the server-made PDF.

return ResponseEntity.ok()
    .header(HttpHeaders.CONTENT_DISPOSITION, ContentDisposition.inline().filename(doc.fileName()).build().toString())
    .contentType(MediaType.APPLICATION_PDF)
    .body(doc.bytes());

Files: web/PrintSetupController.java, templates/preview.html, web/Downloads.java.