Start to implement scroll percentage

messageviewer/src/viewer/webengine/mailwebengineview.cpp

@@ -200,3 +200,25 @@ void MailWebEngineView::handleScrollToAnchor(const QVariant &result)
         }
     }
 }
+
+
+void MailWebEngineView::scrollPageDown(int percent)
+{
+#if 0
+    const qint64 height =  page()->viewportSize().height();
+    const qint64 current = page()->mainFrame()->scrollBarValue(Qt::Vertical);
+    // do arithmetic in higher precision, and check for overflow:
+    const qint64 newPosition = current + height * percent / 100;
+    if (newPosition > std::numeric_limits<int>::max()) {
+        qCWarning(MESSAGEVIEWER_LOG) << "new position" << newPosition << "exceeds range of 'int'!";
+    }
+    page()->mainFrame()->setScrollBarValue(Qt::Vertical, newPosition);
+#endif
+}
+
+void MailWebEngineView::scrollPageUp(int percent)
+{
+#if 0
+    scrollPageDown(-percent);
+#endif
+}

messageviewer/src/viewer/webengine/mailwebengineview.h

@@ -44,6 +44,8 @@ public:
     bool removeAttachmentMarking(const QString &id);
     void markAttachment(const QString &id, const QString &style);
     void scrollToAnchor(const QString &anchor);
+    void scrollPageDown(int percent);
+    void scrollPageUp(int percent);
 public Q_SLOTS:
     void slotZoomChanged(qreal zoom);
 

messageviewer/src/webengine/webenginescript.cpp

@@ -124,6 +124,12 @@ QString WebEngineScript::searchElementPosition(const QString &elementStr)
     return source;
 }
 
+QString WebEngineScript::scrollPercentage(int percent)
+{
+    //TODO
+    return QString();
+}
+
 QString WebEngineScript::scrollUp(int pixel)
 {
     const QString source = QString::fromLatin1("window.scrollBy(0, %1);").arg(-pixel);

messageviewer/src/webengine/webenginescript.h

@@ -35,6 +35,7 @@ MESSAGEVIEWER_EXPORT QString setElementByIdVisible(const QString &elementStr, bo
 MESSAGEVIEWER_EXPORT QString setStyleToElement(const QString &elementStr, const QString &style);
 MESSAGEVIEWER_EXPORT QString scrollDown(int pixel);
 MESSAGEVIEWER_EXPORT QString scrollUp(int pixel);
+MESSAGEVIEWER_EXPORT QString scrollPercentage(int percent);
 }
 }
 #endif // WEBENGINESCRIPT_H