Drop printsupport dependency from core

Prevent linkage of core to widgets by moving printing API from
QWebEnginePage to View and using QPagedPaintDevice (the QtGui ancestor
of QPrinter) where it's needed.

Change-Id: I6ea96edb495b0dcaaa584bbe72632fda025c18d3
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

3 files changed, 140 insertions, 1 deletions

diff --git a/src/webenginewidgets/api/qwebengineview.cpp b/src/webenginewidgets/api/qwebengineview.cpp
index 9ce954e06..a34c841e3 100644
--- a/src/webenginewidgets/api/qwebengineview.cpp
+++ b/src/webenginewidgets/api/qwebengineview.cpp
@@ -80,6 +80,13 @@
 #include <QStyle>
 #include <QGuiApplication>
 
+#if QT_CONFIG(webengine_printing_and_pdf)
+#include "printing/printer_worker.h"
+
+#include <QPrinter>
+#include <QThread>
+#endif
+
 QT_BEGIN_NAMESPACE
 
 void QWebEngineViewPrivate::pageChanged(QWebEnginePage *oldPage, QWebEnginePage *newPage)
@@ -344,7 +351,13 @@ static QAccessibleInterface *webAccessibleFactory(const QString &, QObject *obje
 #endif // QT_NO_ACCESSIBILITY
 
 QWebEngineViewPrivate::QWebEngineViewPrivate()
-    : page(0), m_dragEntered(false), m_ownsPage(false), m_contextRequest(nullptr)
+    : page(0)
+    , 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);
@@ -495,6 +508,61 @@ QObject *QWebEngineViewPrivate::accessibilityParentObject()
     return q;
 }
 
+void QWebEngineViewPrivate::didPrintPage(quint64 requestId, 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;
+        page->d_ptr->m_callbacks.invoke(requestId, *(result.data()));
+        return;
+    }
+
+    QThread *printerThread = new QThread;
+    QObject::connect(printerThread, &QThread::finished, printerThread, &QThread::deleteLater);
+    printerThread->start();
+
+    QtWebEngineCore::PrinterWorker *printerWorker = new QtWebEngineCore::PrinterWorker(result, currentPrinter);
+    printerWorker->m_deviceResolution = currentPrinter->resolution();
+    printerWorker->m_firstPageFirst = currentPrinter->pageOrder() == QPrinter::FirstPageFirst;
+    printerWorker->m_documentCopies = currentPrinter->copyCount();
+    printerWorker->m_collateCopies = currentPrinter->collateCopies();
+
+    QObject::connect(printerWorker, &QtWebEngineCore::PrinterWorker::resultReady, q, [requestId, this](bool success) {
+        currentPrinter = nullptr;
+        page->d_ptr->m_callbacks.invoke(requestId, success);
+    });
+
+    QObject::connect(printerWorker, &QtWebEngineCore::PrinterWorker::resultReady, printerThread, &QThread::quit);
+    QObject::connect(printerThread, &QThread::finished, printerWorker, &QtWebEngineCore::PrinterWorker::deleteLater);
+
+    printerWorker->moveToThread(printerThread);
+    QMetaObject::invokeMethod(printerWorker, "print");
+
+#else
+    // we should never enter this branch, but just for safe-keeping...
+    Q_UNUSED(result);
+    page->d_ptr->m_callbacks.invoke(requestId, QByteArray());
+#endif
+}
+
+void QWebEngineViewPrivate::didPrintPageToPdf(const QString &filePath, bool success)
+{
+    Q_Q(QWebEngineView);
+        Q_EMIT q->pdfPrintingFinished(filePath, success);
+}
+
+void QWebEngineViewPrivate::printRequested()
+{
+    Q_Q(QWebEngineView);
+    QTimer::singleShot(0, q, [q]() {
+        Q_EMIT q->printRequested();
+    });
+}
+
 bool QWebEngineViewPrivate::isVisible() const
 {
     Q_Q(const QWebEngineView);
@@ -878,6 +946,62 @@ QWebEngineContextMenuRequest *QWebEngineView::lastContextMenuRequest() const
     return d->m_contextRequest;
 }
 
+void QWebEngineView::printToPdf(const QString &filePath, const QPageLayout &layout)
+{
+#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, filePath);
+#else
+    Q_UNUSED(filePath);
+    Q_UNUSED(layout);
+#endif
+}
+
+void QWebEngineView::printToPdf(const QWebEngineCallback<const QByteArray&> &resultCallback, const QPageLayout &layout)
+{
+#if QT_CONFIG(webengine_printing_and_pdf)
+    Q_D(QWebEngineView);
+    if (d->currentPrinter) {
+        qWarning("Cannot print to PDF while printing at the same time.");
+        page()->d_ptr->m_callbacks.invokeEmpty(resultCallback);
+        return;
+    }
+    page()->d_ptr->ensureInitialized();
+    quint64 requestId = page()->d_ptr->adapter->printToPDFCallbackResult(layout);
+    page()->d_ptr->m_callbacks.registerCallback(requestId, resultCallback);
+#else
+    Q_UNUSED(layout);
+    page()->d_ptr->m_callbacks.invokeEmpty(resultCallback);
+#endif
+}
+
+void QWebEngineView::print(QPrinter *printer, const QWebEngineCallback<bool> &resultCallback)
+{
+#if QT_CONFIG(webengine_printing_and_pdf)
+    Q_D(QWebEngineView);
+    if (d->currentPrinter) {
+        qWarning("Cannot print page on printer %ls: Already printing on a device.", qUtf16Printable(printer->printerName()));
+        page()->d_ptr->m_callbacks.invokeDirectly(resultCallback, false);
+        return;
+    }
+
+    d->currentPrinter = printer;
+    page()->d_ptr->ensureInitialized();
+    quint64 requestId = page()->d_ptr->adapter->printToPDFCallbackResult(printer->pageLayout(),
+                                                                         printer->colorMode() == QPrinter::Color,
+                                                                         false);
+    page()->d_ptr->m_callbacks.registerCallback(requestId, resultCallback);
+#else
+    Q_UNUSED(printer);
+    page()->d_ptr->m_callbacks.invokeDirectly(resultCallback, false);
+#endif
+}
+
 #ifndef QT_NO_ACCESSIBILITY
 bool QWebEngineViewAccessible::isValid() const
 {
diff --git a/src/webenginewidgets/api/qwebengineview.h b/src/webenginewidgets/api/qwebengineview.h
index d7f9d6a45..136df0b93 100644
--- a/src/webenginewidgets/api/qwebengineview.h
+++ b/src/webenginewidgets/api/qwebengineview.h
@@ -51,6 +51,7 @@
 
 QT_BEGIN_NAMESPACE
 class QContextMenuEvent;
+class QPrinter;
 class QUrl;
 class QWebEnginePage;
 class QWebEngineSettings;
@@ -107,6 +108,10 @@ public:
 #endif
     QWebEngineContextMenuRequest *lastContextMenuRequest() const;
 
+    void printToPdf(const QString &filePath, const QPageLayout &layout = QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF()));
+    void printToPdf(const QWebEngineCallback<const QByteArray&> &resultCallback, const QPageLayout &layout = QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF()));
+    void print(QPrinter *printer, const QWebEngineCallback<bool> &resultCallback);
+
 public Q_SLOTS:
     void stop();
     void back();
@@ -124,6 +129,8 @@ Q_SIGNALS:
     void iconChanged(const QIcon&);
     void renderProcessTerminated(QWebEnginePage::RenderProcessTerminationStatus terminationStatus,
                              int exitCode);
+    void pdfPrintingFinished(const QString &filePath, bool success);
+    void printRequested();
 
 protected:
     virtual QWebEngineView *createWindow(QWebEnginePage::WebWindowType type);
diff --git a/src/webenginewidgets/api/qwebengineview_p.h b/src/webenginewidgets/api/qwebengineview_p.h
index 40f195522..71e7d04f7 100644
--- a/src/webenginewidgets/api/qwebengineview_p.h
+++ b/src/webenginewidgets/api/qwebengineview_p.h
@@ -58,6 +58,7 @@
 #include <QtWidgets/qaccessiblewidget.h>
 
 namespace QtWebEngineCore {
+class QPrinter;
 class RenderWidgetHostViewQtDelegateWidget;
 class RenderWidgetHostViewQtDelegate;
 }
@@ -92,6 +93,10 @@ public:
     QWebEngineContextMenuRequest *lastContextMenuRequest() const override;
     QWebEnginePage *createPageForWindow(QWebEnginePage::WebWindowType type) override;
     QObject *accessibilityParentObject() override;
+    void didPrintPage(quint64 requestId, QSharedPointer<QByteArray> result) override;
+    void didPrintPageToPdf(const QString &filePath, bool success) override;
+    void printRequested() override;
+
     QWebEngineViewPrivate();
     virtual ~QWebEngineViewPrivate();
     static void bindPageAndView(QWebEnginePage *page, QWebEngineView *view);
@@ -108,6 +113,9 @@ public:
     bool m_dragEntered;
     mutable bool m_ownsPage;
     QWebEngineContextMenuRequest *m_contextRequest;
+#if QT_CONFIG(webengine_printing_and_pdf)
+    QPrinter *currentPrinter;
+#endif
 };
 
 #ifndef QT_NO_ACCESSIBILITY