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Print, share & export (1.63)

LoB pattern for “send this view somewhere” without a QWinUI3 print engine. Prefer grab → save → reveal over inventing a second chrome stack.

Step Tool Module
Capture Item.grabToImage Qt Quick
Choose path FilePicker.saveFile Platform
Show in folder WindowHelper.revealFileInFolder Platform
Optional print Qt PrintSupport (QPrinter) in your app Not a QWinUI3 dependency

Gallery: Print / share / export (PrintSharePage).

Related: system-integration.md · drag-drop.md · shell-extras.md · window-helper.md · platform-linux-wayland.md.

Out of scope (1.63): built-in PDF product, cloud share providers, screenshot farms (python scripts/smoke_gallery.py visual subset is separate).

Recipe A — Export a view as PNG

import QtQuick
import QWinUI3.Platform

Item {
    id: exportRoot
    // … the chrome or chart you want to capture …

    function exportPng() {
        FilePicker.saveFile(
            qsTr("Export PNG"),
            ["PNG (*.png)", "All (*.*)"],
            function (path) {
                if (!path || !path.length)
                    return // cancelled
                exportRoot.grabToImage(function (result) {
                    if (!result || !result.saveToFile(path)) {
                        console.warn("export failed", path)
                        return
                    }
                    if (!WindowHelper.revealFileInFolder(path))
                        console.warn("reveal failed", path)
                })
            },
            "png",
            Window.window)
    }
}
Topic Detail
Size Grab uses the item’s current size (including DPR). Prefer a fixed export host if you need stable pixels.
Timing Call after layout/polish; for animated content set Theme.reducedMotion or wait a frame.
Filters Always pass Window.window to FilePicker (HWND / portal parent).
Reveal After save, revealFileInFolder lands the user on the file — shell-extras.md.

Recipe B — Share path (clipboard / drop)

Once you have a file path:

WindowHelper.copyText(path)           // clipboard — docs/drag-drop.md
// or CopyButton { textToCopy: path }

Dragging out of the app / OLE shell DnD remains out of scope (same as drag-drop.md).

Recipe C — Print / PDF via Qt PrintSupport (app-side)

QWinUI3 does not link Qt PrintSupport. Apps that need system print dialogs or PDF writers:

  1. Enable PrintSupport in your CMake (find_package(Qt6 COMPONENTS PrintSupport)).
  2. Grab to an image (Recipe A) or paint with QPainter on QPrinter.
  3. On Linux, PDF via QPrinter::PdfFormat is often more reliable than a physical printer from CI/headless hosts.

Sketch (C++):

#include <QPrinter>
#include <QPainter>
#include <QImage>

bool printImage(const QImage &img, const QString &pdfPath)
{
    QPrinter printer(QPrinter::HighResolution);
    if (!pdfPath.isEmpty()) {
        printer.setOutputFormat(QPrinter::PdfFormat);
        printer.setOutputFileName(pdfPath);
    }
    QPainter p(&printer);
    if (!p.isActive())
        return false;
    const QRect r = printer.pageRect(QPrinter::DevicePixel).toRect();
    p.drawImage(r, img);
    return true;
}

Then reveal the PDF with WindowHelper.revealFileInFolder from QML after the C++ call returns the path.

Win / Linux caveats

Host Expectation
Windows FilePicker uses IFileDialog; reveal uses Explorer /select. Grab needs a visible / realized item.
Linux X11 Portal FilePicker gets parent_window. Reveal best-effort via FileManager DBus / open parent dir.
Linux Wayland Pass Window.window anyway; portal parent may be empty — platform-linux-wayland.md. Prefer Solid chrome shells.
Headless / CI --smoke / offscreen: do not expect interactive FilePicker; use Recipe A only in interactive Gallery.
PrintSupport Optional app dependency — not redistributed by QWinUI3 shared zips.

Checklist

  • [ ] Export uses grabToImage + FilePicker.saveFile + revealFileInFolder
  • [ ] FilePicker always gets Window.window
  • [ ] No cloud share SDK required for the LoB path
  • [ ] Print/PDF only if the app already owns PrintSupport
  • [ ] Skim upgrade-notes.md for this minor
Page Role
Print / share / export Interactive grab + save + reveal
System integration FilePicker / reveal demos
FileDropZone Import side of the pipe
CopyButton Path / text clipboard