dart_pdf_printing

Optional PDF printing for Flutter apps using dart_pdf_editor. Includes the same layout preview and native printing used by the DartPDF app. The viewer and editor packages do not depend on this plugin: add it only when your app needs printing. No PDFium or other bundled PDF engine is added.

Install

Requires Flutter 3.47 or later. Add the plugin alongside the editor:

dependencies:
  dart_pdf_editor: ^4.3.0
  dart_pdf_printing: ^0.1.0

During development before the first pub.flutter-io.cn release, use a local checkout:

  dart_pdf_printing:
    path: /path/to/dart-pdf/packages/dart_pdf_printing

Run flutter pub get and rebuild the app. Flutter registers the platform implementation automatically; there is no runner code to copy or registration function to call. This follows Flutter's plugin packaging model.

Preview and print

import 'package:dart_pdf_printing/dart_pdf_printing.dart';

await printPdfWithPreview(
  context,
  document: document,
  title: 'Report.pdf',
  currentPage: viewerController.currentPage, // zero-based
  selectedPages: editingController.selectedPages,
);

Put this call in your own Print button or Cmd/Ctrl+P action. For an active editing session, unfocus the inline editor, apply pending focus changes and call editingController.finishInk() before passing editingController.document. See the complete host example. The preview captures a separate revision; printing never edits the source. Catch errors from the returned future to present your app's error UI.

The preview includes all/current/selected/custom page ranges, document paper or A0–A5/Letter/Legal/Tabloid, orientation, scaling, margins, offsets, rotation, cropping, n-up layout, copies, collation, reverse order, document/markup selection, dimming and hyperlink borders. Its preview and print output use the same sheet composer. addFiles is an optional async callback returning List<PdfDocument> for batch printing; your app handles file selection and passwords. Omit it to hide Add Files.

On Windows, the preview also selects the printer, color, duplex mode and paper source, then submits directly to that queue. Printer properties opens the driver's advanced settings only when requested. A missing saved printer must be replaced explicitly. Other platforms keep their native print dialogs.

Print choices persist across app launches, including changes made before Cancel. Common options and per-printer choices use shared_preferences; Windows also saves the complete driver preferences for each queue. Defaults resets document options while retaining the printer. Crop regions and added batch files apply only to the current job.

Use your own UI

Print PDF bytes directly, opening only the system print dialog:

await printPdfBytes(bytes: pdfBytes, title: 'Report.pdf');

Or compose physical sheets programmatically, then print them:

final sheets = preparePrintDocument(
  document,
  PrintSettings(
    pages: [0, 2, 3], // zero-based, in output order
    paperSize: PrintPaperSize.a4,
    scaling: PrintScaling.multiple,
    pagesPerSheet: 2,
  ),
);
await printPdfWithProgress(
  context,
  bytes: sheets,
  title: 'Report.pdf',
  useDocumentPageSize: true,
);

showPrintPreviewDialog returns PrintPreviewResult? for hosts that want to handle the confirmed document/settings themselves. Cancel returns null. It also returns the Windows destination: pass it to printPdfBytes or printPdfWithProgress. When composing a duplex job, pass twoSided: true to preparePrintDocument so copies repeat front/back pairs and odd copies get blank backs. printPdfWithPreview handles both steps automatically.

For a custom Windows printer picker, use listPrintPrinters, loadPrintPrinterSettings, and showPrintPrinterProperties, then pass a PrintDestination to the print call. These printer discovery and driver APIs are Windows-only. Omitting destination keeps the system print dialog.

printPdfBytes also accepts onProgress(rendered, total) for desktop page preparation. System dialog cancellation is a normal completion; the API does not claim that a physical printer finished the job. Concurrent native jobs on one channel fail with PlatformException(code: 'print_in_progress').

Localization

Print widgets default to English when no delegate is registered. To use the bundled translations, add DartPdfPrintingLocalizations.delegate to your MaterialApp.localizationsDelegates and include its supportedLocales in your app's locale list. For a small standalone host:

MaterialApp(
  localizationsDelegates: [
    ...DartPdfPrintingLocalizations.localizationsDelegates,
    DartPdfEditorLocalizations.delegate,
  ],
  supportedLocales: DartPdfPrintingLocalizations.supportedLocales,
  home: yourScreen,
)

Platforms

Platform	Print backend	Host setup
macOS 12+	PDFKit / AppKit	Enable com.apple.security.print in both entitlements files for sandboxed apps.
iOS / iPadOS	UIKit / AirPrint	iOS 15+; the plugin anchors the iPad popover to the registrar's view controller.
Android	Android PrintManager	API 24+; requires an attached Activity and a system print service.
Windows	GDI vector replay with direct queue selection	Normal Flutter Windows build tools; no downloaded native PDF library.
Linux	GTK / Cairo vector replay	Flutter's GTK 3 toolchain plus libsecret-1-dev and libjsoncpp-dev for the editor's dependencies.
Web	Browser PDF viewer and print dialog	Browser must support inline PDF printing and permit the print action.

For sandboxed macOS hosts, add this inside the <dict> in both macos/Runner/DebugProfile.entitlements and Release.entitlements:

<key>com.apple.security.print</key>
<true/>

Apple, Android and browser backends receive the PDF itself. Windows and Linux receive drawing operations from this engine, including outlined embedded fonts; unsupported advanced effects can be flattened or approximated by the vector encoder. Raster fallback is available for backends without vector capability. Printer media, duplex, trays and hardware margins remain under system/printer control; Windows reports incompatible paper substitutions instead of clipping composed sheets. Virtual PDF printers can still request an output filename. Browser/mobile services and mixed-media macOS jobs may negotiate paper sizes or scaling differently from the prepared preview.

The backend uses channel dev.milanko.dart_pdf_printing. Native registration supports ordinary Flutter hosts and desktop engines without an implicit view. Each native plugin owns its job state; Windows print preferences are scoped to the embedding application's executable rather than shared with DartPDF.

Development

From the repository root, run flutter pub get, then from this directory run flutter test. The app at ../../app consumes this plugin and exercises native registration in its platform builds. The package's tests cover sheet composition, pixel output, layout preview, localization, native protocol and job isolation. Physical-printer output still depends on the printer/driver.

tool/test_print_plugin.sh macos (or windows / linux) creates a temporary plain Flutter host and checks native registration through the plugin's channel. On headless Linux, run it under xvfb-run -a. Set DART_PDF_FLUTTER_BIN if Flutter is not on PATH. These checks also run in the desktop CI matrix and never submit an actual print job.