Return printToPdf to QWebEnginePage

It doesn't use QPrinter and can be done using QtGui classes only.

Change-Id: I0e14563c1bb5e93d9803bb1a807f702b1a2a5315
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Kirill Burtsev <kirill.burtsev@qt.io>
(cherry picked from commit b405ed26336a44ad4f359cdb4e1909e31c113cd4)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

6 files changed, 130 insertions, 62 deletions

diff --git a/src/core/api/qwebenginepage.cpp b/src/core/api/qwebenginepage.cpp
index c17276a1f..17e138920 100644
--- a/src/core/api/qwebenginepage.cpp
+++ b/src/core/api/qwebenginepage.cpp
@@ -321,6 +321,8 @@ void QWebEnginePagePrivate::loadFinished(QWebEngineLoadingInfo info)
 
 void QWebEnginePagePrivate::didPrintPageToPdf(const QString &filePath, bool success)
 {
+    Q_Q(QWebEnginePage);
+    Q_EMIT q->pdfPrintingFinished(filePath, success);
     if (view)
         view->didPrintPageToPdf(filePath, success);
 }
@@ -470,8 +472,28 @@ void QWebEnginePagePrivate::didFetchDocumentInnerText(quint64 requestId, const Q
 
 void QWebEnginePagePrivate::didPrintPage(quint64 requestId, QSharedPointer<QByteArray> result)
 {
+#if QT_CONFIG(webengine_printing_and_pdf)
+    Q_Q(QWebEnginePage);
+
+    // If no currentPrinter is set that means that were printing to PDF only.
+    if (!currentPrinter) {
+        if (!result.data())
+            return;
+        if (auto callback = m_pdfResultCallbacks.take(requestId))
+            callback(*(result.data()));
+        return;
+    }
+
     if (view)
-        view->didPrintPage(requestId, result);
+        view->didPrintPage(currentPrinter, result);
+    else
+        currentPrinter = nullptr;
+#else
+    // we should never enter this branch, but just for safe-keeping...
+    Q_UNUSED(result);
+    if (auto callback = m_pdfResultCallbacks.take(requestId))
+        callback(QByteArray());
+#endif
 }
 
 bool QWebEnginePagePrivate::passOnFocus(bool reverse)
@@ -1688,6 +1710,10 @@ void QWebEnginePagePrivate::setToolTip(const QString &toolTipText)
 
 void QWebEnginePagePrivate::printRequested()
 {
+    Q_Q(QWebEnginePage);
+    QTimer::singleShot(0, q, [q]() {
+        Q_EMIT q->printRequested();
+    });
     if (view)
         view->printRequested();
 }
@@ -2234,6 +2260,74 @@ QSizeF QWebEnginePage::contentsSize() const
 */
 
 /*!
+    \fn void QWebEnginePage::pdfPrintingFinished(const QString &filePath, bool success)
+
+    This signal is emitted when printing the web page into a PDF file has
+    finished.
+    \a filePath will contain the path the file was requested to be created
+    at, and \a success will be \c true if the file was successfully created and
+    \c false otherwise.
+
+    \sa printToPdf()
+*/
+
+/*!
+    Renders the current content of the page into a PDF document and saves it
+    in the location specified in \a filePath.
+    The page size and orientation of the produced PDF document are taken from
+    the values specified in \a pageLayout, while the range of pages printed is
+    taken from \a ranges with the default being printing all pages.
+
+    This method issues an asynchronous request for printing the web page into
+    a PDF and returns immediately.
+    To be informed about the result of the request, connect to the signal
+    pdfPrintingFinished().
+
+    If a file already exists at the provided file path, it will be overwritten.
+    \sa pdfPrintingFinished()
+*/
+void QWebEnginePage::printToPdf(const QString &filePath, const QPageLayout &layout, const QPageRanges &ranges)
+{
+#if QT_CONFIG(webengine_printing_and_pdf)
+    Q_D(QWebEnginePage);
+    d->ensureInitialized();
+    d->adapter->printToPDF(layout, ranges, filePath);
+#else
+    Q_UNUSED(filePath);
+    Q_UNUSED(layout);
+    Q_UNUSED(ranges);
+#endif
+}
+
+/*!
+    Renders the current content of the page into a PDF document and returns a byte array containing the PDF data
+    as parameter to \a resultCallback.
+    The page size and orientation of the produced PDF document are taken from the values specified in \a pageLayout,
+    while the range of pages printed is taken from \a ranges with the default being printing all pages.
+
+    The \a resultCallback must take a const reference to a QByteArray as parameter. If printing was successful, this byte array
+    will contain the PDF data, otherwise, the byte array will be empty.
+
+    \warning We guarantee that the callback (\a resultCallback) is always called, but it might be done
+    during page destruction. When QWebEnginePage is deleted, the callback is triggered with an invalid
+    value and it is not safe to use the corresponding QWebEnginePage or QWebEngineView instance inside it.
+*/
+void QWebEnginePage::printToPdf(const std::function<void(const QByteArray&)> &resultCallback, const QPageLayout &layout, const QPageRanges &ranges)
+{
+    Q_D(QWebEnginePage);
+#if QT_CONFIG(webengine_printing_and_pdf)
+    d->ensureInitialized();
+    quint64 requestId = d->adapter->printToPDFCallbackResult(layout, ranges);
+    d->m_pdfResultCallbacks.insert(requestId, resultCallback);
+#else
+    Q_UNUSED(layout);
+    Q_UNUSED(ranges);
+    if (resultCallback)
+        resultCallback(QByteArray());
+#endif
+}
+
+/*!
     \internal
 */
 void QWebEnginePage::acceptAsNewWindow(QWebEngineNewWindowRequest &request)
diff --git a/src/core/api/qwebenginepage.h b/src/core/api/qwebenginepage.h
index 1bdcf6539..9f35cffeb 100644
--- a/src/core/api/qwebenginepage.h
+++ b/src/core/api/qwebenginepage.h
@@ -49,6 +49,8 @@
 #include <QtCore/qurl.h>
 #include <QtCore/qvariant.h>
 #include <QtGui/qaction.h>
+#include <QtGui/qpagelayout.h>
+#include <QtGui/qpageranges.h>
 
 #include <functional>
 
@@ -301,6 +303,13 @@ public:
     bool recentlyAudible() const;
     qint64 renderProcessPid() const;
 
+    void printToPdf(const QString &filePath,
+                    const QPageLayout &layout = QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF()),
+                    const QPageRanges &ranges = {});
+    void printToPdf(const std::function<void(const QByteArray&)> &resultCallback,
+                    const QPageLayout &layout = QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF()),
+                    const QPageRanges &ranges = {});
+
     void setInspectedPage(QWebEnginePage *page);
     QWebEnginePage *inspectedPage() const;
     void setDevToolsPage(QWebEnginePage *page);
@@ -355,6 +364,9 @@ Q_SIGNALS:
     void recentlyAudibleChanged(bool recentlyAudible);
     void renderProcessPidChanged(qint64 pid);
 
+    void pdfPrintingFinished(const QString &filePath, bool success);
+    void printRequested();
+
     void visibleChanged(bool visible);
 
     void lifecycleStateChanged(LifecycleState state);
diff --git a/src/core/api/qwebenginepage_p.h b/src/core/api/qwebenginepage_p.h
index f9eb2ad71..40b6ddd29 100644
--- a/src/core/api/qwebenginepage_p.h
+++ b/src/core/api/qwebenginepage_p.h
@@ -70,6 +70,7 @@ class WebContentsAdapter;
 }
 
 QT_BEGIN_NAMESPACE
+class QPrinter;
 class QWebEngineFindTextResult;
 class QWebEngineHistory;
 class QWebEnginePage;
@@ -102,7 +103,7 @@ public:
     virtual void unhandledKeyEvent(QKeyEvent *event) = 0;
     virtual bool passOnFocus(bool reverse) = 0;
     virtual QObject *accessibilityParentObject() = 0;
-    virtual void didPrintPage(quint64 requestId, QSharedPointer<QByteArray> result) = 0;
+    virtual void didPrintPage(QPrinter *&printer, QSharedPointer<QByteArray> result) = 0;
     virtual void didPrintPageToPdf(const QString &filePath, bool success) = 0;
     virtual void printRequested() = 0;
 };
@@ -222,9 +223,13 @@ public:
     qreal defaultZoomFactor;
     QTimer wasShownTimer;
     QtWebEngineCore::RenderWidgetHostViewQtDelegateWidget *widget = nullptr;
+#if QT_CONFIG(webengine_printing_and_pdf)
+    QPrinter *currentPrinter = nullptr;
+#endif
 
     mutable QMap<quint64, std::function<void(const QVariant &)>> m_variantCallbacks;
     mutable QMap<quint64, std::function<void(const QString &)>> m_stringCallbacks;
+    QMap<quint64, std::function<void(const QByteArray&)>> m_pdfResultCallbacks;
     mutable QAction *actions[QWebEnginePage::WebActionCount];
 };
 
diff --git a/src/webenginewidgets/api/qwebengineview.cpp b/src/webenginewidgets/api/qwebengineview.cpp
index aed80427c..d312fe70c 100644
--- a/src/webenginewidgets/api/qwebengineview.cpp
+++ b/src/webenginewidgets/api/qwebengineview.cpp
@@ -359,9 +359,6 @@ QWebEngineViewPrivate::QWebEngineViewPrivate()
     , m_dragEntered(false)
     , m_ownsPage(false)
     , m_contextRequest(nullptr)
-#if QT_CONFIG(webengine_printing_and_pdf)
-    , currentPrinter(nullptr)
-#endif
 {
 #ifndef QT_NO_ACCESSIBILITY
     QAccessible::installFactory(&webAccessibleFactory);
@@ -512,19 +509,12 @@ QObject *QWebEngineViewPrivate::accessibilityParentObject()
     return q;
 }
 
-void QWebEngineViewPrivate::didPrintPage(quint64 requestId, QSharedPointer<QByteArray> result)
+void QWebEngineViewPrivate::didPrintPage(QPrinter *&currentPrinter, QSharedPointer<QByteArray> result)
 {
 #if QT_CONFIG(webengine_printing_and_pdf)
     Q_Q(QWebEngineView);
 
-    // If no currentPrinter is set that means that were printing to PDF only.
-    if (!currentPrinter) {
-        if (!result.data())
-            return;
-        if (auto callback = m_pdfResultCallbacks.take(requestId))
-            callback(*(result.data()));
-        return;
-    }
+    Q_ASSERT(currentPrinter);
 
     QThread *printerThread = new QThread;
     QObject::connect(printerThread, &QThread::finished, printerThread, &QThread::deleteLater);
@@ -536,7 +526,7 @@ void QWebEngineViewPrivate::didPrintPage(quint64 requestId, QSharedPointer<QByte
     printerWorker->m_documentCopies = currentPrinter->copyCount();
     printerWorker->m_collateCopies = currentPrinter->collateCopies();
 
-    QObject::connect(printerWorker, &QtWebEngineCore::PrinterWorker::resultReady, q, [this, q](bool success) {
+    QObject::connect(printerWorker, &QtWebEngineCore::PrinterWorker::resultReady, q, [q, &currentPrinter](bool success) {
         currentPrinter = nullptr;
         Q_EMIT q->printFinished(success);
     });
@@ -548,17 +538,15 @@ void QWebEngineViewPrivate::didPrintPage(quint64 requestId, QSharedPointer<QByte
     QMetaObject::invokeMethod(printerWorker, "print");
 
 #else
-    // we should never enter this branch, but just for safe-keeping...
+    Q_UNUSED(currentPrinter);
     Q_UNUSED(result);
-    if (auto callback = m_pdfResultCallbacks.take(requestId))
-        callback(QByteArray());
 #endif
 }
 
 void QWebEngineViewPrivate::didPrintPageToPdf(const QString &filePath, bool success)
 {
     Q_Q(QWebEngineView);
-        Q_EMIT q->pdfPrintingFinished(filePath, success);
+    Q_EMIT q->pdfPrintingFinished(filePath, success);
 }
 
 void QWebEngineViewPrivate::printRequested()
@@ -1000,19 +988,7 @@ QWebEngineContextMenuRequest *QWebEngineView::lastContextMenuRequest() const
 */
 void QWebEngineView::printToPdf(const QString &filePath, const QPageLayout &layout, const QPageRanges &ranges)
 {
-#if QT_CONFIG(webengine_printing_and_pdf)
-    Q_D(QWebEngineView);
-    if (d->currentPrinter) {
-        qWarning("Cannot print to PDF while printing at the same time.");
-        return;
-    }
-    page()->d_ptr->ensureInitialized();
-    page()->d_ptr->adapter->printToPDF(layout, ranges, filePath);
-#else
-    Q_UNUSED(filePath);
-    Q_UNUSED(layout);
-    Q_UNUSED(ranges);
-#endif
+    page()->printToPdf(filePath, layout, ranges);
 }
 
 /*!
@@ -1032,23 +1008,7 @@ void QWebEngineView::printToPdf(const QString &filePath, const QPageLayout &layo
 */
 void QWebEngineView::printToPdf(const std::function<void(const QByteArray&)> &resultCallback, const QPageLayout &layout, const QPageRanges &ranges)
 {
-    Q_D(QWebEngineView);
-#if QT_CONFIG(webengine_printing_and_pdf)
-    if (d->currentPrinter) {
-        qWarning("Cannot print to PDF while printing at the same time.");
-        if (resultCallback)
-            resultCallback(QByteArray());
-        return;
-    }
-    page()->d_ptr->ensureInitialized();
-    quint64 requestId = page()->d_ptr->adapter->printToPDFCallbackResult(layout, ranges);
-    d->m_pdfResultCallbacks.insert(requestId, resultCallback);
-#else
-    Q_UNUSED(layout);
-    Q_UNUSED(ranges);
-    if (resultCallback)
-        resultCallback(QByteArray());
-#endif
+    page()->printToPdf(resultCallback, layout, ranges);
 }
 
 /*!
@@ -1093,13 +1053,12 @@ void QWebEngineView::printToPdf(const std::function<void(const QByteArray&)> &re
 void QWebEngineView::print(QPrinter *printer)
 {
 #if QT_CONFIG(webengine_printing_and_pdf)
-    Q_D(QWebEngineView);
-    if (d->currentPrinter) {
+    if (page()->d_ptr->currentPrinter) {
         qWarning("Cannot print page on printer %ls: Already printing on a device.", qUtf16Printable(printer->printerName()));
         return;
     }
 
-    d->currentPrinter = printer;
+    page()->d_ptr->currentPrinter = printer;
     page()->d_ptr->ensureInitialized();
     page()->d_ptr->adapter->printToPDFCallbackResult(printer->pageLayout(),
                                                      printer->pageRanges(),
diff --git a/src/webenginewidgets/api/qwebengineview_p.h b/src/webenginewidgets/api/qwebengineview_p.h
index db22c95b5..13b346df9 100644
--- a/src/webenginewidgets/api/qwebengineview_p.h
+++ b/src/webenginewidgets/api/qwebengineview_p.h
@@ -94,7 +94,7 @@ public:
     QWebEngineContextMenuRequest *lastContextMenuRequest() const override;
     QWebEnginePage *createPageForWindow(QWebEnginePage::WebWindowType type) override;
     QObject *accessibilityParentObject() override;
-    void didPrintPage(quint64 requestId, QSharedPointer<QByteArray> result) override;
+    void didPrintPage(QPrinter *&printer, QSharedPointer<QByteArray> result) override;
     void didPrintPageToPdf(const QString &filePath, bool success) override;
     void printRequested() override;
 
@@ -114,10 +114,6 @@ public:
     bool m_dragEntered;
     mutable bool m_ownsPage;
     QWebEngineContextMenuRequest *m_contextRequest;
-#if QT_CONFIG(webengine_printing_and_pdf)
-    QPrinter *currentPrinter;
-#endif
-    QMap<quint64, std::function<void(const QByteArray&)>> m_pdfResultCallbacks;
 };
 
 #ifndef QT_NO_ACCESSIBILITY
diff --git a/tests/auto/widgets/printing/tst_printing.cpp b/tests/auto/widgets/printing/tst_printing.cpp
index 3f1344ed4..0559fb787 100644
--- a/tests/auto/widgets/printing/tst_printing.cpp
+++ b/tests/auto/widgets/printing/tst_printing.cpp
@@ -58,10 +58,10 @@ void tst_Printing::printToPdfBasic()
     view.load(QUrl("qrc:///resources/basic_printing_page.html"));
     QTRY_VERIFY(spy.count() == 1);
 
-    QSignalSpy savePdfSpy(&view, &QWebEngineView::pdfPrintingFinished);
+    QSignalSpy savePdfSpy(view.page(), &QWebEnginePage::pdfPrintingFinished);
     QPageLayout layout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF(0.0, 0.0, 0.0, 0.0));
     QString path = tempDir.path() + "/print_1_success.pdf";
-    view.printToPdf(path, layout);
+    view.page()->printToPdf(path, layout);
     QTRY_VERIFY2(savePdfSpy.count() == 1, "Printing to PDF file failed without signal");
 
     QList<QVariant> successArguments = savePdfSpy.takeFirst();
@@ -73,7 +73,7 @@ void tst_Printing::printToPdfBasic()
 #else
     path = tempDir.path() + "/print_|2_failed.pdf";
 #endif
-    view.printToPdf(path, QPageLayout());
+    view.page()->printToPdf(path, QPageLayout());
     QTRY_VERIFY2(savePdfSpy.count() == 1, "Printing to PDF file failed without signal");
 
     QList<QVariant> failedArguments = savePdfSpy.takeFirst();
@@ -81,11 +81,11 @@ void tst_Printing::printToPdfBasic()
     QVERIFY2(failedArguments.at(1).toBool() == false, "Printing to PDF file succeeded though it should fail");
 
     CallbackSpy<QByteArray> successfulSpy;
-    view.printToPdf(successfulSpy.ref(), layout);
+    view.page()->printToPdf(successfulSpy.ref(), layout);
     QVERIFY(successfulSpy.waitForResult().length() > 0);
 
     CallbackSpy<QByteArray> failedInvalidLayoutSpy;
-    view.printToPdf(failedInvalidLayoutSpy.ref(), QPageLayout());
+    view.page()->printToPdf(failedInvalidLayoutSpy.ref(), QPageLayout());
     QCOMPARE(failedInvalidLayoutSpy.waitForResult().length(), 0);
 }
 
@@ -95,6 +95,7 @@ void tst_Printing::printRequest()
      QPageLayout layout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF(0.0, 0.0, 0.0, 0.0));
      QSignalSpy loadFinishedSpy(&view, &QWebEngineView::loadFinished);
      QSignalSpy printRequestedSpy(&view, &QWebEngineView::printRequested);
+     QSignalSpy printRequestedSpy2(view.page(), &QWebEnginePage::printRequested);
      QSignalSpy savePdfSpy(&view, &QWebEngineView::pdfPrintingFinished);
      CallbackSpy<QByteArray> resultSpy;
 
@@ -102,6 +103,7 @@ void tst_Printing::printRequest()
      QTRY_VERIFY(loadFinishedSpy.count() == 1);
      view.page()->runJavaScript("window.print()");
      QTRY_VERIFY(printRequestedSpy.count() == 1);
+     QVERIFY(printRequestedSpy2.count() == 1);
      //check if printing still works
      view.printToPdf(resultSpy.ref(), layout);
      const QByteArray data = resultSpy.waitForResult();