PageThumbnailer: Rewrite to load thumbnails with QML WebEngineView

This way it is possible to get thumbnail even without showing the
webview.

src/lib/data/data.qrc

@@ -1,7 +1,8 @@
 <RCC>
     <qresource prefix="/">
+        <file>data/bookmarks.json</file>
         <file>data/browsedata.db</file>
         <file>data/profiles.ini</file>
-        <file>data/bookmarks.json</file>
+        <file>data/thumbnailer.qml</file>
     </qresource>
 </RCC>

src/lib/data/data/thumbnailer.qml

@@ -0,0 +1,15 @@
+import QtQuick 2.2
+import QtWebEngine 1.0
+
+WebEngineView {
+    width: 1280
+    height: 720
+
+    onLoadingChanged: {
+        if (loadRequest.status == WebEngineView.LoadStartedStatus)
+            return;
+
+        var ok = loadRequest.status == WebEngineView.LoadSucceededStatus;
+        thumbnailer.createThumbnail(ok);
+    }
+}

src/lib/lib.pro

@@ -1,4 +1,4 @@
-QT += webenginewidgets webenginewidgets-private webchannel network widgets sql script
+QT += webenginewidgets webenginewidgets-private webchannel network widgets sql script quickwidgets
 
 TARGET = QupZilla
 TEMPLATE = lib

src/lib/tools/pagethumbnailer.cpp

@@ -19,24 +19,21 @@
 
 #include <QTimer>
 #include <QApplication>
-#include <QWebEngineView>
+
+#include <QQmlContext>
+#include <QQuickItem>
+#include <QQuickWidget>
 
 PageThumbnailer::PageThumbnailer(QObject* parent)
     : QObject(parent)
-    , m_view(new QWebEngineView())
+    , m_view(new QQuickWidget())
     , m_size(QSize(450, 253))
     , m_loadTitle(false)
 {
-    // Every page should fit in this resolution
-    m_view->resize(QSize(1280, 720));
-
-    // Well ...
-    QWidget *w = QApplication::activeWindow();
+    m_view->setAttribute(Qt::WA_DontShowOnScreen);
+    m_view->setSource(QUrl(QSL("qrc:data/thumbnailer.qml")));
+    m_view->rootContext()->setContextProperty(QSL("thumbnailer"), this);
     m_view->show();
-    if (w) {
-        QApplication::setActiveWindow(w);
-        w->activateWindow();
-    }
 }
 
 void PageThumbnailer::setSize(const QSize &size)
@@ -79,9 +76,14 @@ QString PageThumbnailer::title()
 
 void PageThumbnailer::start()
 {
-    m_view->load(m_url);
-
-    connect(m_view, &QWebEngineView::loadFinished, this, &PageThumbnailer::createThumbnail);
+    if (m_view->rootObject()) {
+        m_view->rootObject()->setProperty("url", m_url);
+    }
+    else {
+        QTimer::singleShot(0, this, [this]() {
+            emit thumbnailCreated(QPixmap());
+        });
+    }
 }
 
 void PageThumbnailer::createThumbnail(bool status)
@@ -92,8 +94,8 @@ void PageThumbnailer::createThumbnail(bool status)
     }
 
     QTimer::singleShot(1000, this, [this]() {
-        m_title = m_view->title().trimmed();
-        emit thumbnailCreated(m_view->grab().scaled(m_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation));
+        m_title = m_view->rootObject()->property("title").toString().trimmed();
+        emit thumbnailCreated(QPixmap::fromImage(m_view->grabFramebuffer().scaled(m_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation)));
     });
 }
 

src/lib/tools/pagethumbnailer.h

@@ -24,7 +24,7 @@
 
 #include "qzcommon.h"
 
-class QWebEngineView;
+class QQuickWidget;
 class QPixmap;
 
 class QUPZILLA_EXPORT PageThumbnailer : public QObject
@@ -49,12 +49,10 @@ signals:
     void thumbnailCreated(const QPixmap &);
 
 public slots:
-
-private slots:
     void createThumbnail(bool status);
 
 private:
-    QWebEngineView* m_view;
+    QQuickWidget *m_view;
 
     QSize m_size;
     QUrl m_url;