ticket:5760 Preserve the scroll position in documentation browser

OMEdit/OMEdit/OMEditGUI/Modeling/DocumentationWidget.cpp

@@ -379,6 +379,8 @@ DocumentationWidget::DocumentationWidget(QWidget *pParent)
   // navigation history list
   mpDocumentationHistoryList = new QList<DocumentationHistory>();
   mDocumentationHistoryPos = -1;
+  setExecutingPreviousNextButtons(false);
+  setScrollPosition(QPoint(0, 0));
   // Documentation viewer layout
   QGridLayout *pGridLayout = new QGridLayout;
   pGridLayout->setContentsMargins(0, 0, 0, 0);
@@ -422,6 +424,18 @@ void DocumentationWidget::showDocumentation(LibraryTreeItem *pLibraryTreeItem)
     saveDocumentation(pLibraryTreeItem);
     return;
   }
+  // write the scroll position
+  if (!isExecutingPreviousNextButtons()) {
+    saveScrollPosition();
+  }
+  // read the scroll position
+  int index = mpDocumentationHistoryList->indexOf(DocumentationHistory(pLibraryTreeItem));
+  if (index > -1 && isExecutingPreviousNextButtons()) {
+    setScrollPosition(mpDocumentationHistoryList->at(index).mScrollPosition);
+  } else {
+    setScrollPosition(QPoint(0, 0));
+  }
+  // read documentation
   QString documentation = MainWindow::instance()->getOMCProxy()->getDocumentationAnnotation(pLibraryTreeItem);
   writeDocumentationFile(documentation);
   mpDocumentationViewer->setUrl(QUrl::fromLocalFile(mDocumentationFile.fileName()));
@@ -507,6 +521,19 @@ QString DocumentationWidget::queryCommandValue(const QString &commandName)
   return result.toString();
 }
 
+/*!
+ * \brief DocumentationWidget::saveScrollPosition
+ * Saves the scroll position of the current page.
+ */
+void DocumentationWidget::saveScrollPosition()
+{
+  if (mDocumentationHistoryPos > -1 && mpDocumentationHistoryList->size() > 0) {
+    DocumentationHistory documentationHistory = mpDocumentationHistoryList->at(mDocumentationHistoryPos);
+    documentationHistory.mScrollPosition = mpDocumentationViewer->page()->mainFrame()->scrollPosition();
+    mpDocumentationHistoryList->replace(mDocumentationHistoryPos, documentationHistory);
+  }
+}
+
 /*!
  * \brief DocumentationWidget::createPixmapForToolButton
  * Creates a new pixmap which contains the QIcon and the QColor in the bottom.
@@ -631,9 +658,12 @@ void DocumentationWidget::updateDocumentationHistory(LibraryTreeItem *pLibraryTr
 void DocumentationWidget::previousDocumentation()
 {
   if (mDocumentationHistoryPos > 0) {
+    saveScrollPosition();
     mDocumentationHistoryPos--;
+    setExecutingPreviousNextButtons(true);
     LibraryTreeModel *pLibraryTreeModel = MainWindow::instance()->getLibraryWidget()->getLibraryTreeModel();
     pLibraryTreeModel->showModelWidget(mpDocumentationHistoryList->at(mDocumentationHistoryPos).mpLibraryTreeItem);
+    setExecutingPreviousNextButtons(false);
   }
 }
 
@@ -645,9 +675,12 @@ void DocumentationWidget::previousDocumentation()
 void DocumentationWidget::nextDocumentation()
 {
   if ((mDocumentationHistoryPos + 1) < mpDocumentationHistoryList->count()) {
+    saveScrollPosition();
     mDocumentationHistoryPos++;
+    setExecutingPreviousNextButtons(true);
     LibraryTreeModel *pLibraryTreeModel = MainWindow::instance()->getLibraryWidget()->getLibraryTreeModel();
     pLibraryTreeModel->showModelWidget(mpDocumentationHistoryList->at(mDocumentationHistoryPos).mpLibraryTreeItem);
+    setExecutingPreviousNextButtons(false);
   }
 }
 
@@ -1140,6 +1173,9 @@ DocumentationViewer::DocumentationViewer(DocumentationWidget *pDocumentationWidg
   connect(page(), SIGNAL(linkClicked(QUrl)), SLOT(processLinkClick(QUrl)));
   connect(page(), SIGNAL(linkHovered(QString,QString,QString)), SLOT(processLinkHover(QString,QString,QString)));
   createActions();
+  if (!isContentEditable) {
+    connect(this, SIGNAL(loadFinished(bool)), SLOT(pageLoaded(bool)));
+  }
 }
 
 /*!
@@ -1267,6 +1303,18 @@ void DocumentationViewer::showContextMenu(QPoint point)
   menu.exec(mapToGlobal(point));
 }
 
+/*!
+ * \brief DocumentationViewer::pageLoaded
+ * Scrolls the page after its finished loading.
+ * \param ok
+ */
+void DocumentationViewer::pageLoaded(bool ok)
+{
+  Q_UNUSED(ok);
+  const QPoint scrollPosition = mpDocumentationWidget->getScrollPosition();
+  page()->mainFrame()->scroll(scrollPosition.x(), scrollPosition.y());
+}
+
 /*!
  * \brief DocumentationViewer::createWindow
  * \param type

OMEdit/OMEdit/OMEditGUI/Modeling/DocumentationWidget.h

@@ -51,7 +51,12 @@ class DocumentationHistory
 {
 public:
   LibraryTreeItem *mpLibraryTreeItem;
-  DocumentationHistory(LibraryTreeItem *pLibraryTreeItem) {mpLibraryTreeItem = pLibraryTreeItem;}
+  QPoint mScrollPosition;
+  DocumentationHistory(LibraryTreeItem *pLibraryTreeItem)
+  {
+    mpLibraryTreeItem = pLibraryTreeItem;
+    mScrollPosition = QPoint(0, 0);
+  }
   bool operator==(const DocumentationHistory &documentationHistory) const
   {
     return (documentationHistory.mpLibraryTreeItem == this->mpLibraryTreeItem);
@@ -80,6 +85,11 @@ class DocumentationWidget : public QWidget
   void execCommand(const QString &commandName, const QString &valueArgument);
   bool queryCommandState(const QString &commandName);
   QString queryCommandValue(const QString &commandName);
+  void saveScrollPosition();
+  bool isExecutingPreviousNextButtons() const {return mExecutingPreviousNextButtons;}
+  void setExecutingPreviousNextButtons(bool executingPreviousNextButtons) {mExecutingPreviousNextButtons = executingPreviousNextButtons;}
+  QPoint getScrollPosition() const {return mScrollPosition;}
+  void setScrollPosition(const QPoint &scrollPosition) {mScrollPosition = scrollPosition;}
 private:
   QFile mDocumentationFile;
   QAction *mpPreviousAction;
@@ -126,6 +136,8 @@ class DocumentationWidget : public QWidget
   EditType mEditType;
   QList<DocumentationHistory> *mpDocumentationHistoryList;
   int mDocumentationHistoryPos;
+  bool mExecutingPreviousNextButtons;
+  QPoint mScrollPosition;
 
   QPixmap createPixmapForToolButton(QColor color, QIcon icon);
   void updatePreviousNextButtons();
@@ -177,6 +189,7 @@ public slots:
   void requestFinished();
   void processLinkHover(QString link, QString title, QString textContent);
   void showContextMenu(QPoint point);
+  void pageLoaded(bool ok);
 protected:
   virtual QWebView* createWindow(QWebPage::WebWindowType type) override;
   virtual void keyPressEvent(QKeyEvent *event) override;

OMEdit/OMEdit/OMEditGUI/Modeling/LibraryTreeWidget.cpp

@@ -1816,7 +1816,6 @@ void LibraryTreeModel::showModelWidget(LibraryTreeItem *pLibraryTreeItem, bool s
           (pLibraryTreeItem->mClassInformation.preferredView.isEmpty() && pLibraryTreeItem->isDocumentationClass()) ||
           (pLibraryTreeItem->mClassInformation.preferredView.isEmpty() &&
            OptionsDialog::instance()->getGeneralSettingsPage()->getDefaultView().compare(Helper::documentationView) == 0))) {
-    MainWindow::instance()->getDocumentationWidget()->showDocumentation(pLibraryTreeItem);
     bool state = MainWindow::instance()->getDocumentationDockWidget()->blockSignals(true);
     MainWindow::instance()->getDocumentationDockWidget()->show();
     MainWindow::instance()->getDocumentationDockWidget()->blockSignals(state);