Dialogs & printing

JDesk provides in-process, app-modal file dialogs and printing, so you never shell out to osascript (dialogs that belong to another process, aren't modal to your window, and don't follow your app's dark mode).

File open/save dialogs#

// Save — pre-fill a name and a type filter.
FileDialogResult saved = context.application().showSaveDialog(
        FileDialog.SaveDialog.withName("Export invoice", "invoice-1024.pdf",
            new FileDialog.Filter("PDF", List.of("pdf"))))
        .toCompletableFuture().join();
saved.path().ifPresent(path -> writePdf(path));

// Open — one or many files of a given type.
FileDialogResult picked = context.application().showOpenDialog(
        new FileDialog.OpenDialog("Import images", Optional.empty(),
            List.of(new FileDialog.Filter("Images", List.of("png", "jpg"))),
            /* allowMultiple */ true, /* chooseDirectories */ false))
        .toCompletableFuture().join();
for (String path : picked.paths()) { importImage(path); }

isCancelled() / an empty paths() means the user dismissed the dialog. The dialogs are modal to the application and follow its appearance.

Platform status: macOS uses NSOpenPanel/NSSavePanel (live-verified). Windows uses comdlg32 GetOpenFileNameW/GetSaveFileNameW; Linux uses GtkFileChooserDialog — both implemented and compile-verified (a modal dialog can't be driven on headless CI).

Printing the current page#

context.application().window(windowId).orElseThrow().print();

This opens the OS print dialog for the window's page content (macOS NSPrintOperation — live-verified; Linux webkit_print_operation_run_dialog — compile-verified). On Windows the WebView2 print UI is not yet wired, so print() reports "not supported" there.

Printing a file straight to a printer#

For unattended label/receipt printing — pick a printer and paper size, no preview app:

context.application().printFile(
        PrintJob.of("/var/labels/order-1024.pdf")
            .toPrinter("Zebra-ZD410")
            .withPaperSize("Custom.4x6in")
            .withCopies(2))
    .toCompletableFuture().join();

Platform status: macOS and Linux submit through the CUPS lp command (verified: a job to a non-existent printer is rejected, proving it reaches the spooler rather than silently succeeding). Windows uses the ShellExecute print/printto verb (default vs. named printer) — it does not honor copies/paperSize (a documented gap). Printing runs off the UI thread, so it is safe to call from a command handler.