Fixed docking into empty main dock container, fixed tab handling to properly show the right dock widget tab when removing a dock widget, fixed tab menu to only show visible tabs, tab menu is now dynamically created just befor menu is shown

src/DockAreaTabBar.cpp

@@ -18,6 +18,7 @@
 #include "DockAreaWidget.h"
 #include "DockOverlay.h"
 #include "DockManager.h"
+#include "DockWidget.h"
 
 namespace ads
 {
@@ -166,6 +167,10 @@ void CDockAreaTabBar::startFloating(const QPoint& Pos)
 	CFloatingDockContainer* FloatingWidget = new CFloatingDockContainer(d->DockArea);
 	FloatingWidget->startFloating(Pos, Size);
 	d->FloatingWidget = FloatingWidget;
+	if (d->FloatingWidget->hasSingleDockWidget())
+	{
+		emit d->FloatingWidget->firstDockWidget()->topLevelChanged(true);
+	}
 }
 } // namespace ads
 

src/DockAreaWidget.cpp

@@ -41,6 +41,7 @@
 #include <QMenu>
 #include <QSplitter>
 #include <QXmlStreamWriter>
+#include <QVector>
 
 
 #include "DockContainerWidget.h"
@@ -50,11 +51,14 @@
 #include "DockOverlay.h"
 #include "DockAreaTabBar.h"
 
+#include <iostream>
+
 
 namespace ads
 {
 static const char* const INDEX_PROPERTY = "index";
 static const char* const ACTION_PROPERTY = "action";
+static const char* const DOCKWIDGET_PROPERTY = "dockwidget";
 static const int APPEND = -1;
 
 
@@ -75,6 +79,8 @@ struct DockAreaWidgetPrivate
 	QPushButton* CloseButton;
 	int TabsLayoutInitCount;
 	CDockManager* DockManager = nullptr;
+	QVector<CDockWidget*> OpenDockWidgets;
+	bool MenuOutdated = true;
 
 	/**
 	 * Private data constructor
@@ -99,7 +105,7 @@ struct DockAreaWidgetPrivate
 	 */
 	CDockWidgetTab* titleWidgetAt(int index)
 	{
-		return dockWidgetAt(index)->titleBar();
+		return dockWidgetAt(index)->tabWidget();
 	}
 
 	/**
@@ -130,6 +136,11 @@ struct DockAreaWidgetPrivate
 	 * Update the tabs menu if dock widget order changed or if dock widget has
 	 * been removed
 	 */
+	void markTabsMenuOutdated();
+
+	/**
+	 * Updates the tabs menu if it is outdated
+	 */
 	void updateTabsMenu();
 
 	/**
@@ -178,7 +189,9 @@ void DockAreaWidgetPrivate::createTabBar()
 	TabsMenuButton->setFlat(true);
 	TabsMenuButton->setIcon(_this->style()->standardIcon(QStyle::SP_TitleBarUnshadeButton));
 	TabsMenuButton->setMaximumWidth(TabsMenuButton->iconSize().width());
-	TabsMenuButton->setMenu(new QMenu(TabsMenuButton));
+	QMenu* TabsMenu = new QMenu(TabsMenuButton);
+	_this->connect(TabsMenu, SIGNAL(aboutToShow()), SLOT(onTabsMenuAboutToShow()));
+	TabsMenuButton->setMenu(TabsMenu);
 	TopLayout->addWidget(TabsMenuButton, 0);
 	TabsMenuButton->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 	_this->connect(TabsMenuButton->menu(), SIGNAL(triggered(QAction*)),
@@ -232,20 +245,39 @@ void DockAreaWidgetPrivate::addTabsMenuEntry(CDockWidget* DockWidget,
 	{
 		Action = menu->addAction(DockWidget->icon(), DockWidget->windowTitle());
 	}
+	Action->setProperty(DOCKWIDGET_PROPERTY, QVariant::fromValue(DockWidget));
 	QVariant vAction = QVariant::fromValue(Action);
 	DockWidget->setProperty(ACTION_PROPERTY, vAction);
 }
 
 
+//============================================================================
+void DockAreaWidgetPrivate::markTabsMenuOutdated()
+{
+	MenuOutdated = true;
+}
+
+
 //============================================================================
 void DockAreaWidgetPrivate::updateTabsMenu()
 {
+	if (!MenuOutdated)
+	{
+		return;
+	}
+
 	QMenu* menu = TabsMenuButton->menu();
 	menu->clear();
 	for (int i = 0; i < ContentsLayout->count(); ++i)
 	{
+		if (dockWidgetAt(i)->isClosed())
+		{
+			continue;
+		}
 		addTabsMenuEntry(dockWidgetAt(i), APPEND, menu);
 	}
+
+	MenuOutdated = false;
 }
 
 
@@ -313,17 +345,16 @@ void CDockAreaWidget::insertDockWidget(int index, CDockWidget* DockWidget,
 	bool Activate)
 {
 	d->ContentsLayout->insertWidget(index, DockWidget);
-	DockWidget->titleBar()->setDockAreaWidget(this);
+	DockWidget->tabWidget()->setDockAreaWidget(this);
-	auto TitleBar = DockWidget->titleBar();
+	auto TabWidget = DockWidget->tabWidget();
-	d->TabsLayout->insertWidget(index, TitleBar);
+	d->TabsLayout->insertWidget(index, TabWidget);
-	TitleBar->show();
+	TabWidget->show();
-	connect(TitleBar, SIGNAL(clicked()), this, SLOT(onDockWidgetTitleClicked()));
+	connect(TabWidget, SIGNAL(clicked()), this, SLOT(onDockWidgetTitleClicked()));
 	DockWidget->setProperty(INDEX_PROPERTY, index);
 	if (Activate)
 	{
 		setCurrentIndex(index);
 	}
-	d->addTabsMenuEntry(DockWidget, index);
 	DockWidget->setDockArea(this);
 }
 
@@ -332,13 +363,18 @@ void CDockAreaWidget::insertDockWidget(int index, CDockWidget* DockWidget,
 void CDockAreaWidget::removeDockWidget(CDockWidget* DockWidget)
 {
 	qDebug() << "CDockAreaWidget::removeDockWidget";
+	auto NextDockWidget = nextOpenDockWidget(DockWidget);
+
 	d->ContentsLayout->removeWidget(DockWidget);
-	auto TitleBar = DockWidget->titleBar();
+	auto TitleBar = DockWidget->tabWidget();
 	TitleBar->hide();
 	d->TabsLayout->removeWidget(TitleBar);
 	disconnect(TitleBar, SIGNAL(clicked()), this, SLOT(onDockWidgetTitleClicked()));
-	setCurrentIndex(d->ContentsLayout->currentIndex());
+	if (NextDockWidget)
-	d->updateTabsMenu();
+	{
+		setCurrentDockWidget(NextDockWidget);
+		d->markTabsMenuOutdated();
+	}
 
 	CDockContainerWidget* DockContainer = dockContainer();
 	if (d->ContentsLayout->isEmpty())
@@ -550,7 +586,6 @@ void CDockAreaWidget::reorderDockWidget(int fromIndex, int toIndex)
 		Menu->insertAction(Menu->actions().at(toIndex), TabsAction);
 	}
 
-
 	// now reorder contents and title bars
 	QLayoutItem* liFrom = nullptr;
 	liFrom = d->TabsLayout->takeAt(fromIndex);
@@ -561,11 +596,21 @@ void CDockAreaWidget::reorderDockWidget(int fromIndex, int toIndex)
 }
 
 
+//============================================================================
+void CDockAreaWidget::toggleDockWidgetView(CDockWidget* DockWidget, bool Open)
+{
+	Q_UNUSED(DockWidget);
+	Q_UNUSED(Open);
+	d->markTabsMenuOutdated();
+}
+
+
 //============================================================================
 void CDockAreaWidget::onTabsMenuActionTriggered(QAction* Action)
 {
-	int Index = d->TabsMenuButton->menu()->actions().indexOf(Action);
+	QVariant vDockWidget = Action->property(DOCKWIDGET_PROPERTY);
-	setCurrentIndex(Index);
+	CDockWidget* DockWidget = vDockWidget.value<CDockWidget*>();
+	setCurrentDockWidget(DockWidget);
 }
 
 
@@ -591,6 +636,40 @@ void CDockAreaWidget::saveState(QXmlStreamWriter& s) const
 	s.writeEndElement();
 }
 
+
+//============================================================================
+CDockWidget* CDockAreaWidget::nextOpenDockWidget(CDockWidget* DockWidget) const
+{
+	auto OpenDockWidgets = openedDockWidgets();
+	if (OpenDockWidgets.count() > 1)
+	{
+		CDockWidget* NextDockWidget;
+		if (OpenDockWidgets.last() == DockWidget)
+		{
+			NextDockWidget = OpenDockWidgets[OpenDockWidgets.count() - 2];
+		}
+		else
+		{
+			int NextIndex = OpenDockWidgets.indexOf(DockWidget) + 1;
+			NextDockWidget = OpenDockWidgets[NextIndex];
+		}
+
+		return NextDockWidget;
+	}
+	else
+	{
+		return nullptr;
+	}
+}
+
+
+//============================================================================
+void CDockAreaWidget::onTabsMenuAboutToShow()
+{
+	std::cout << "CDockAreaWidget::onTabsMenuAboutToShow()" << std::endl;
+	d->updateTabsMenu();
+}
+
 } // namespace ads
 
 //---------------------------------------------------------------------------

src/DockAreaWidget.h

@@ -59,11 +59,14 @@ private:
 	friend class CDockContainerWidget;
 	friend class DockContainerWidgetPrivate;
 	friend class CDockWidgetTab;
+	friend struct DockWidgetPrivate;
+	friend class CDockWidget;
 
 private slots:
 	void onDockWidgetTitleClicked();
 	void onTabsMenuActionTriggered(QAction* Action);
 	void onCloseButtonClicked();
+	void onTabsMenuAboutToShow();
 
 protected:
 	/**
@@ -97,6 +100,18 @@ protected:
 	 */
 	void reorderDockWidget(int fromIndex, int toIndex);
 
+	/**
+	 * Called from dock widget if it is opened or closed
+	 */
+	void toggleDockWidgetView(CDockWidget* DockWidget, bool Open);
+
+	/**
+	 * This is a helper function to get the next open dock widget to activate
+	 * if the given DockWidget will be closed or removed.
+	 * The function returns the next widget that should be activated or
+	 * nullptr in case there are no more open widgets in this area.
+	 */
+	CDockWidget* nextOpenDockWidget(CDockWidget* DockWidget) const;
 
 public:
 	/**
@@ -178,7 +193,9 @@ public:
 
 public slots:
 	/**
-	 * This sets the index position of the current tab page.
+	 * This activates the tab for the given tab index.
+	 * If the dock widget for the given tab is not visible, the this function
+	 * call will make it visible.
 	 */
 	void setCurrentIndex(int index);
 

src/DockContainerWidget.cpp

@@ -54,6 +54,26 @@ namespace ads
 {
 static unsigned int zOrderCounter = 0;
 
+
+/**
+ * Converts dock area ID to an index for array access
+ */
+static int areaIdToIndex(DockWidgetArea area)
+{
+	switch (area)
+	{
+	case LeftDockWidgetArea: return 0;
+	case RightDockWidgetArea: return 1;
+	case TopDockWidgetArea: return 2;
+	case BottomDockWidgetArea: return 3;
+	case CenterDockWidgetArea: return 4;
+	default:
+		return 4;
+	}
+
+	return 4;
+}
+
 /**
  * Helper function to ease insertion of dock area into splitter
  */
@@ -81,6 +101,7 @@ struct DockContainerWidgetPrivate
 	QGridLayout* Layout = nullptr;
 	QSplitter* RootSplitter;
 	bool isFloating = false;
+	CDockAreaWidget* LastAddedAreaCache[5]{0, 0, 0, 0, 0};
 
 	/**
 	 * Private data constructor
@@ -172,7 +193,6 @@ void DockContainerWidgetPrivate::dropIntoContainer(CFloatingDockContainer* Float
 	auto InsertParam = internal::dockAreaInsertParameters(area);
 	auto NewDockAreas = FloatingWidget->dockContainer()->findChildren<CDockAreaWidget*>(
 		QString(), Qt::FindChildrenRecursively);
-	CDockWidget* DockWidget = FloatingWidget->dockContainer()->findChild<CDockWidget*>();
 	QSplitter* Splitter = RootSplitter;
 
 	if (DockAreas.count() <= 1)
@@ -209,9 +229,12 @@ void DockContainerWidgetPrivate::dropIntoContainer(CFloatingDockContainer* Float
 	RootSplitter = Splitter;
 	addDockAreasToList(NewDockAreas);
 	FloatingWidget->deleteLater();
-	if (DockWidget)
+	// If we dropped the floating widget into the main dock container that does
+	// not contain any dock widgets, then splitter is invisible and we need to
+	// show it to display the docked widgets
+	if (!Splitter->isVisible())
 	{
-		DockWidget->toggleView(true);
+		Splitter->show();
 	}
 	_this->dumpLayout();
 }
@@ -503,6 +526,8 @@ bool DockContainerWidgetPrivate::restoreDockArea(QXmlStreamReader& s,
 		qDebug() << "Dock Widget found - parent " << DockWidget->parent();
 		DockArea->addDockWidget(DockWidget);
 
+		// We hide the DockArea here to prevent the short display (the flashing)
+		// of the dock areas during application startup
 		DockArea->hide();
 		DockWidget->setToggleViewActionChecked(!Closed);
 		DockWidget->setProperty("closed", Closed);
@@ -565,6 +590,7 @@ CDockAreaWidget* DockContainerWidgetPrivate::dockWidgetIntoContainer(DockWidgetA
 	CDockAreaWidget* NewDockArea = new CDockAreaWidget(DockManager, _this);
 	NewDockArea->addDockWidget(Dockwidget);
 	addDockArea(NewDockArea, area);
+	LastAddedAreaCache[areaIdToIndex(area)] = NewDockArea;
 	return NewDockArea;
 }
 
@@ -689,7 +715,6 @@ CDockContainerWidget::CDockContainerWidget(CDockManager* DockManager, QWidget *p
 {
 	d->isFloating = dynamic_cast<CFloatingDockContainer*>(parent) != 0;
 
-	//setStyleSheet("background: green;");
 	d->DockManager = DockManager;
 	if (DockManager != this)
 	{
@@ -905,6 +930,8 @@ void CDockContainerWidget::dropFloatingWidget(CFloatingDockContainer* FloatingWi
 	CDockAreaWidget* DockArea = dockAreaAt(TargetPos);
 	auto dropArea = InvalidDockWidgetArea;
 	auto ContainerDropArea = d->DockManager->containerOverlay()->dropAreaUnderCursor();
+	CDockWidget* TopLevelDockWidget = FloatingWidget->hasSingleDockWidget() ?
+		FloatingWidget->firstDockWidget() : nullptr;
 	if (DockArea)
 	{
 		auto dropOverlay = d->DockManager->dockAreaOverlay();
@@ -933,6 +960,13 @@ void CDockContainerWidget::dropFloatingWidget(CFloatingDockContainer* FloatingWi
 			d->dropIntoContainer(FloatingWidget, dropArea);
 		}
 	}
+
+	// If we drop a floating widget with only one single dock widget, then we
+	// drop a top level widget that changes from floating to docked now
+	if (TopLevelDockWidget)
+	{
+		emit TopLevelDockWidget->topLevelChanged(false);
+	}
 }
 
 
@@ -1047,6 +1081,13 @@ void CDockContainerWidget::dumpLayout()
 }
 
 
+//============================================================================
+CDockAreaWidget* CDockContainerWidget::lastAddedDockAreaWidget(DockWidgetArea area) const
+{
+	return d->LastAddedAreaCache[areaIdToIndex(area)];
+}
+
+
 } // namespace ads
 
 //---------------------------------------------------------------------------

src/DockContainerWidget.h

@@ -103,6 +103,13 @@ protected:
 	 */
 	bool restoreState(QXmlStreamReader& Stream, bool Testing);
 
+	/**
+	 * This function returns the last added dock area widget for the given
+	 * area identifier or 0 if no dock area widget has been added for the given
+	 * area
+	 */
+	CDockAreaWidget* lastAddedDockAreaWidget(DockWidgetArea area) const;
+
 public:
 	/**
 	 * Default Constructor

src/DockManager.cpp

@@ -361,7 +361,8 @@ bool CDockManager::restoreState(const QByteArray &state, int version)
     	{
     		CDockAreaWidget* DockArea = DockContainer->dockArea(i);
     		int CurrentIndex = DockArea->property("currentIndex").toInt();
-    		if (CurrentIndex < DockArea->count() && DockArea->count() > 1 && CurrentIndex > -1)
+    		int OpenDockWidgetCount = DockArea->openedDockWidgets().count();
+    		if (CurrentIndex < OpenDockWidgetCount && OpenDockWidgetCount > 1 && CurrentIndex > -1)
     		{
     			DockArea->setCurrentIndex(CurrentIndex);
     		}
@@ -382,6 +383,30 @@ CDockAreaWidget* CDockManager::addDockWidget(DockWidgetArea area,
 }
 
 
+//============================================================================
+CDockAreaWidget* CDockManager::addDockWidgetTab(DockWidgetArea area,
+	CDockWidget* Dockwidget)
+{
+	CDockAreaWidget* AreaWidget = lastAddedDockAreaWidget(area);
+	if (AreaWidget)
+	{
+		return addDockWidget(ads::CenterDockWidgetArea, Dockwidget, AreaWidget);
+	}
+	else
+	{
+		return addDockWidget(area, Dockwidget, AreaWidget);
+	}
+}
+
+
+//============================================================================
+CDockAreaWidget* CDockManager::addDockWidgetTabToArea(CDockWidget* Dockwidget,
+	CDockAreaWidget* DockAreaWidget)
+{
+	return addDockWidget(ads::CenterDockWidgetArea, Dockwidget, DockAreaWidget);
+}
+
+
 //============================================================================
 CDockWidget* CDockManager::findDockWidget(const QString& ObjectName)
 {

src/DockManager.h

@@ -128,6 +128,22 @@ public:
 	CDockAreaWidget* addDockWidget(DockWidgetArea area, CDockWidget* Dockwidget,
 		CDockAreaWidget* DockAreaWidget = nullptr);
 
+	/**
+	 * This function will add the given Dockwidget to the given dock area as
+	 * a new tab.
+	 * If no dock area widget exists for the given area identifier, a new
+	 * dock area widget is created.
+	 */
+	CDockAreaWidget* addDockWidgetTab(DockWidgetArea area,
+		CDockWidget* Dockwidget);
+
+	/**
+	 * This function will add the given Dockwidget to the given DockAreaWidget
+	 * as a new tab.
+	 */
+	CDockAreaWidget* addDockWidgetTabToArea(CDockWidget* Dockwidget,
+		CDockAreaWidget* DockAreaWidget);
+
 	/**
 	 * Searches for a registered doc widget with the given ObjectName
 	 * \return Return the found dock widget or nullptr if a dock widget with the

src/DockWidget.cpp

@@ -59,7 +59,7 @@ struct DockWidgetPrivate
 	CDockWidget* _this;
 	QBoxLayout* Layout;
 	QWidget* Widget = nullptr;
-	CDockWidgetTab* TitleWidget;
+	CDockWidgetTab* TabWidget;
 	CDockWidget::DockWidgetFeatures Features = CDockWidget::AllDockWidgetFeatures;
 	CDockManager* DockManager = nullptr;
 	CDockAreaWidget* DockArea = nullptr;
@@ -87,9 +87,11 @@ struct DockWidgetPrivate
 	void hideEmptyParentSplitters();
 
 	/**
-	 * Hides a dock area if all dock widgets in the area are closed
+	 * Hides a dock area if all dock widgets in the area are closed.
+	 * This function updates the current selected tab and hides the parent
+	 * dock area if it is empty
 	 */
-	void hideEmptyParentDockArea();
+	void updateParentDockArea();
 
 	/**
 	 * Hides a floating widget if all dock areas are empty - that means,
@@ -141,8 +143,8 @@ void DockWidgetPrivate::showDockWidget()
 //============================================================================
 void DockWidgetPrivate::hideDockWidget()
 {
-	TitleWidget->hide();
+	TabWidget->hide();
-	hideEmptyParentDockArea();
+	updateParentDockArea();
 	hideEmptyParentSplitters();
 	hideEmptyFloatingWidget();
 }
@@ -164,22 +166,11 @@ void DockWidgetPrivate::hideEmptyParentSplitters()
 
 
 //============================================================================
-void DockWidgetPrivate::hideEmptyParentDockArea()
+void DockWidgetPrivate::updateParentDockArea()
 {
-	auto OpenDockWidgets = DockArea->openedDockWidgets();
+	auto NextDockWidget = DockArea->nextOpenDockWidget(_this);
-	if (OpenDockWidgets.count() > 1)
+	if (NextDockWidget)
 	{
-		CDockWidget* NextDockWidget;
-		if (OpenDockWidgets.last() == _this)
-		{
-			NextDockWidget = OpenDockWidgets[OpenDockWidgets.count() - 2];
-		}
-		else
-		{
-			int NextIndex = OpenDockWidgets.indexOf(_this) + 1;
-			NextDockWidget = OpenDockWidgets[NextIndex];
-		}
-
 		DockArea->setCurrentDockWidget(NextDockWidget);
 	}
 	else
@@ -213,7 +204,7 @@ CDockWidget::CDockWidget(const QString &title, QWidget *parent) :
 	setWindowTitle(title);
 	setObjectName(title);
 
-	d->TitleWidget = new CDockWidgetTab(this);
+	d->TabWidget = new CDockWidgetTab(this);
 	d->ToggleViewAction = new QAction(title);
 	d->ToggleViewAction->setCheckable(true);
 	connect(d->ToggleViewAction, SIGNAL(triggered(bool)), this,
@@ -262,9 +253,9 @@ QWidget* CDockWidget::widget() const
 
 
 //============================================================================
-CDockWidgetTab* CDockWidget::titleBar() const
+CDockWidgetTab* CDockWidget::tabWidget() const
 {
-	return d->TitleWidget;
+	return d->TabWidget;
 }
 
 
@@ -320,7 +311,39 @@ CDockAreaWidget* CDockWidget::dockAreaWidget() const
 //============================================================================
 bool CDockWidget::isFloating() const
 {
-	return dockContainer() ? dockContainer()->isFloating() : false;
+	if (!isInFloatingContainer())
+	{
+		return false;
+	}
+
+	if (dockContainer()->dockAreaCount() != 1)
+	{
+		return false;
+	}
+
+	if (dockContainer()->dockArea(0)->count() != 1)
+	{
+		return false;
+	}
+
+	return true;
+}
+
+
+//============================================================================
+bool CDockWidget::isInFloatingContainer() const
+{
+	if (!dockContainer())
+	{
+		return false;
+	}
+
+	if (!dockContainer()->isFloating())
+	{
+		return false;
+	}
+
+	return true;
 }
 
 
@@ -349,7 +372,7 @@ void CDockWidget::setToggleViewActionMode(eToggleViewActionMode Mode)
 	else
 	{
 		d->ToggleViewAction->setCheckable(false);
-		d->ToggleViewAction->setIcon(d->TitleWidget->icon());
+		d->ToggleViewAction->setIcon(d->TabWidget->icon());
 	}
 }
 
@@ -375,6 +398,8 @@ void CDockWidget::toggleView(bool Open)
 	d->ToggleViewAction->blockSignals(true);
 	d->ToggleViewAction->setChecked(Open);
 	d->ToggleViewAction->blockSignals(false);
+	d->DockArea->toggleDockWidgetView(this, Open);
+
 	if (!Open)
 	{
 		emit closed();
@@ -406,7 +431,7 @@ void CDockWidget::flagAsUnassigned()
 {
 	setParent(d->DockManager);
 	setDockArea(nullptr);
-	titleBar()->setParent(this);
+	tabWidget()->setParent(this);
 }
 
 
@@ -424,7 +449,7 @@ bool CDockWidget::event(QEvent *e)
 //============================================================================
 void CDockWidget::setIcon(const QIcon& Icon)
 {
-	d->TitleWidget->setIcon(Icon);
+	d->TabWidget->setIcon(Icon);
 	if (!d->ToggleViewAction->isCheckable())
 	{
 		d->ToggleViewAction->setIcon(Icon);
@@ -435,7 +460,7 @@ void CDockWidget::setIcon(const QIcon& Icon)
 //============================================================================
 QIcon CDockWidget::icon() const
 {
-	return d->TitleWidget->icon();
+	return d->TabWidget->icon();
 }
 
 

src/DockWidget.h

@@ -164,7 +164,7 @@ public:
 	/**
 	 * Returns the title bar widget of this dock widget
 	 */
-	CDockWidgetTab* titleBar() const;
+	CDockWidgetTab* tabWidget() const;
 
 	/**
 	 * Sets, whether the dock widget is movable, closable, and floatable.
@@ -193,7 +193,7 @@ public:
 
 	/**
 	 * Returns the dock container widget this dock area widget belongs to or 0
-	 * if this dock widget has nt been docked yet
+	 * if this dock widget has not been docked yet
 	 */
 	CDockContainerWidget* dockContainer() const;
 
@@ -205,9 +205,19 @@ public:
 
 	/**
 	 * This property holds whether the dock widget is floating.
+	 * A dock widget is only floating, if it is the one and only widget inside
+	 * of a floating container. If there are more than one dock widget in a
+	 * floating container, the all dock widgets are docked and not floating.
 	 */
 	bool isFloating() const;
 
+	/**
+	 * This function returns true, if this dock widget is in a floating.
+	 * The function returns true, if the dock widget is floating and it also
+	 * returns true if it is docked inside of a floating container.
+	 */
+	bool isInFloatingContainer() const;
+
 	/**
 	 * Returns true, if this dock widget is closed.
 	 */
@@ -266,6 +276,13 @@ signals:
 	 * changed
 	 */
 	void titleChanged(const QString& Title);
+
+	/**
+	 * This signal is emitted when the floating property changes.
+	 * The topLevel parameter is true if the dock widget is now floating;
+	 * otherwise it is false.
+	 */
+	void topLevelChanged(bool topLevel);
 }; // class DockWidget
 }
  // namespace ads

src/DockWidgetTab.cpp

@@ -196,6 +196,7 @@ bool DockWidgetTabPrivate::startFloating()
     auto Overlay = DockWidget->dockManager()->containerOverlay();
 	Overlay->setAllowedAreas(OuterDockAreas);
 	this->FloatingWidget = FloatingWidget;
+	emit DockWidget->topLevelChanged(true);
 	return true;
 }
 

src/FloatingDockContainer.cpp

@@ -481,6 +481,25 @@ bool CFloatingDockContainer::restoreState(QXmlStreamReader& Stream, bool Testing
 }
 
 
+//============================================================================
+bool CFloatingDockContainer::hasSingleDockWidget() const
+{
+	if (d->DockContainer->dockAreaCount() != 1)
+	{
+		return false;
+	}
+
+	return d->DockContainer->dockArea(0)->count() == 1;
+}
+
+
+//============================================================================
+CDockWidget* CFloatingDockContainer::firstDockWidget() const
+{
+	return d->DockContainer->dockArea(0)->dockWidget(0);
+}
+
+
 } // namespace ads
 
 //---------------------------------------------------------------------------

src/FloatingDockContainer.h

@@ -132,6 +132,21 @@ public:
 	 * It can be closed, if all dock widgets in all dock areas can be closed
 	 */
     bool isClosable() const;
+
+    /**
+     * This function returns true, if this floating widget has only one single
+     * dock widget in a single dock area.
+     * The single dock widget is a real top level floating widget because no
+     * other widgets are docked.
+     */
+    bool hasSingleDockWidget() const;
+
+    /**
+     * This function returns the first dock widget in the first dock area.
+     * If the function hasSingleDockWidget() returns true, then this function
+     * returns this single dock widget.
+     */
+    CDockWidget* firstDockWidget() const;
 }; // class FloatingDockContainer
 }
  // namespace ads