Add widgets API for printing on a QPrinter

Renders the content to a PDF document and then renders this on a
QPrinter-backed QPainter using the PDFium library.

PDFium bitmap to QImage conversion based on work by Paulo Pinheiro
<paulvap.os@gmail.com>.

[ChangeLog][QtWebEngineWidgets][Printing] Enables printing QWebPage
content on a QPrinter. Currently does not support previewing the
document. Widgets only for the moment.

Change-Id: I9a5264433093379aee90f5e4f69bf2aee8814f2b
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 29 insertions, 0 deletions

diff --git a/src/webenginewidgets/api/qwebenginepage.cpp b/src/webenginewidgets/api/qwebenginepage.cpp
index c180699f3..428cccd9a 100644
--- a/src/webenginewidgets/api/qwebenginepage.cpp
+++ b/src/webenginewidgets/api/qwebenginepage.cpp
@@ -373,6 +373,13 @@ void QWebEnginePagePrivate::didPrintPage(quint64 requestId, const QByteArray &re
     m_callbacks.invoke(requestId, result);
 }
 
+#ifndef QT_NO_PRINTER
+void QWebEnginePagePrivate::didPrintPageOnPrinter(quint64 requestId, bool result)
+{
+    m_callbacks.invoke(requestId, result);
+}
+#endif
+
 void QWebEnginePagePrivate::passOnFocus(bool reverse)
 {
     if (view)
@@ -1841,6 +1848,28 @@ void QWebEnginePage::printToPdf(const QWebEngineCallback<const QByteArray&> &res
     d->m_callbacks.registerCallback(requestId, resultCallback);
 }
 
+#ifndef QT_NO_PRINTER
+/*!
+    \fn void QWebEnginePage::print(const QPrinter &printer, FunctorOrLambda resultCallback)
+    Renders the current content of the page into a temporary PDF document, then prints it using \a printer.
+
+    The settings for creating and printing the PDF document will be retrieved from the \a printer
+    object.
+    It is the users responsibility to ensure the \a printer remains valid until \a resultCallback
+    has been called.
+
+    The \a resultCallback must take a boolean as parameter. If printing was successful, this
+    boolean will have the value \c true, otherwise, its value will be \c false.
+    \since 5.8
+*/
+void QWebEnginePage::print(QPrinter *printer, const QWebEngineCallback<bool> &resultCallback)
+{
+    Q_D(QWebEnginePage);
+    quint64 requestId = d->adapter->printOnPrinterCallbackResult(printer);
+    d->m_callbacks.registerCallback(requestId, resultCallback);
+}
+#endif // QT_NO_PRINTER
+
 /*!
     \since 5.7