Unbind containers from DockManager to prevent accidental reuse before deletion (#823)

src/DockAreaWidget.cpp

@@ -609,8 +609,7 @@ void CDockAreaWidget::removeDockWidget(CDockWidget* DockWidget)
 		{
 			if(CFloatingDockContainer*  FloatingDockContainer = DockContainer->floatingWidget())
 			{
-				FloatingDockContainer->hide();
-				FloatingDockContainer->deleteLater();
+				FloatingDockContainer->finishDropOperation();
 			}
 		}
 	}

src/DockContainerWidget.cpp

@@ -2217,6 +2217,17 @@ CDockManager* CDockContainerWidget::dockManager() const
 }
 
 
+//===========================================================================
+void CDockContainerWidget::removeFromDockManager()
+{
+	if (d->DockManager)
+	{
+		d->DockManager->removeDockContainer(this);
+		d->DockManager.clear();
+	}
+}
+
+
 //===========================================================================
 void CDockContainerWidget::handleAutoHideWidgetEvent(QEvent* e, QWidget* w)
 {

src/DockContainerWidget.h

@@ -86,6 +86,9 @@ private:
 	friend AutoHideDockContainerPrivate;
 	friend CAutoHideSideBar;
 
+private Q_SLOTS:
+	void removeFromDockManager();
+
 protected:
 	/**
 	 * Handles activation events to update zOrderIndex

src/DockManager.cpp

@@ -768,7 +768,8 @@ void CDockManager::registerFloatingWidget(CFloatingDockContainer* FloatingWidget
 //============================================================================
 void CDockManager::removeFloatingWidget(CFloatingDockContainer* FloatingWidget)
 {
-	d->FloatingWidgets.removeAll(FloatingWidget);
+	int removed = d->FloatingWidgets.removeAll(FloatingWidget);
+	Q_ASSERT(removed == 1);
 }
 
 //============================================================================
@@ -783,7 +784,8 @@ void CDockManager::removeDockContainer(CDockContainerWidget* DockContainer)
 {
 	if (this != DockContainer)
 	{
-		d->Containers.removeAll(DockContainer);
+		int removed = d->Containers.removeAll(DockContainer);
+		Q_ASSERT(removed == 1);
 	}
 }
 

src/FloatingDockContainer.cpp

@@ -370,14 +370,14 @@ struct FloatingDockContainerPrivate
 	eDragState DraggingState = DraggingInactive;
 	QPoint DragStartMousePosition;
 	CDockContainerWidget *DropContainer = nullptr;
-	CDockAreaWidget *SingleDockArea = nullptr;
-	QPoint DragStartPos;
-	bool Hiding = false;
-	bool AutoHideChildren = true;
-	bool HideContentOnNextHide = false;
-#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
-    QWidget* MouseEventHandler = nullptr;
-    CFloatingWidgetTitleBar* TitleBar = nullptr;
+	CDockAreaWidget *SingleDockArea = nullptr;
+	QPoint DragStartPos;
+	bool Hiding = false;
+	bool AutoHideChildren = true;
+	bool HideContentOnNextHide = false;
+#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
+    QWidget* MouseEventHandler = nullptr;
+    CFloatingWidgetTitleBar* TitleBar = nullptr;
 	bool IsResizing = false;
     bool MousePressed = false;
 #endif
@@ -500,6 +500,9 @@ void FloatingDockContainerPrivate::titleMouseReleaseEvent()
 		return;
 	}
 
+	// DockManager will be unlinked from this within DropContainer->dropFloatingWidget
+	const auto OriginalDockManager = this->DockManager.data();
+
 	if (DockManager->dockAreaOverlay()->dropAreaUnderCursor() != InvalidDockWidgetArea
 	 || DockManager->containerOverlay()->dropAreaUnderCursor() != InvalidDockWidgetArea)
 	{
@@ -533,8 +536,8 @@ void FloatingDockContainerPrivate::titleMouseReleaseEvent()
 		DropContainer->dropFloatingWidget(_this, QCursor::pos());
 	}
 
-	DockManager->containerOverlay()->hideOverlay();
-	DockManager->dockAreaOverlay()->hideOverlay();
+	OriginalDockManager->containerOverlay()->hideOverlay();
+	OriginalDockManager->dockAreaOverlay()->hideOverlay();
 }
 
 
@@ -928,11 +931,11 @@ bool CFloatingDockContainer::nativeEvent(const QByteArray &eventType, void *mess
 
 
 //============================================================================
-void CFloatingDockContainer::closeEvent(QCloseEvent *event)
-{
-	ADS_PRINT("CFloatingDockContainer closeEvent");
-	d->setState(DraggingInactive);
-	event->ignore();
+void CFloatingDockContainer::closeEvent(QCloseEvent *event)
+{
+	ADS_PRINT("CFloatingDockContainer closeEvent");
+	d->setState(DraggingInactive);
+	event->ignore();
 	if (!isClosable())
 	{
 		return;
@@ -960,14 +963,14 @@ void CFloatingDockContainer::closeEvent(QCloseEvent *event)
 		return;
 	}
 
-	// New bug (QWebEngineView reload side effect):
-	// when a WebEngine-based dock is tabified into a floating container, the
-	// embedded native/web process can trigger delayed hide/show cycles on the
-	// floating window. If every non-spontaneous hide propagates to
-	// DockWidget->toggleView(false), unrelated tabs are marked closed and seem
+	// New bug (QWebEngineView reload side effect):
+	// when a WebEngine-based dock is tabified into a floating container, the
+	// embedded native/web process can trigger delayed hide/show cycles on the
+	// floating window. If every non-spontaneous hide propagates to
+	// DockWidget->toggleView(false), unrelated tabs are marked closed and seem
 	// to "disappear". We therefore arm HideContentOnNextHide only for the 
-	// explicit close path.
-	d->HideContentOnNextHide = true;
+	// explicit close path.
+	d->HideContentOnNextHide = true;
 
 	// In Qt version after 5.9.2 there seems to be a bug that causes the
 	// QWidget::event() function to not receive any NonClientArea mouse
@@ -975,40 +978,40 @@ void CFloatingDockContainer::closeEvent(QCloseEvent *event)
 	// https://bugreports.qt.io/browse/QTBUG-73295
 	// The following code is a workaround for Qt versions > 5.9.2 that seems
 	// to work
-	// Starting from Qt version 5.12.2 this seems to work again. But
-	// now the QEvent::NonClientAreaMouseButtonPress function returns always
-	// Qt::RightButton even if the left button was pressed
-	this->hide();
-}
-
-//============================================================================
-void CFloatingDockContainer::hideEvent(QHideEvent *event)
-{
-	Super::hideEvent(event);
-    if (event->spontaneous())
-    {
-        return;
-    }
+	// Starting from Qt version 5.12.2 this seems to work again. But
+	// now the QEvent::NonClientAreaMouseButtonPress function returns always
+	// Qt::RightButton even if the left button was pressed
+	this->hide();
+}
+
+//============================================================================
+void CFloatingDockContainer::hideEvent(QHideEvent *event)
+{
+	Super::hideEvent(event);
+    if (event->spontaneous())
+    {
+        return;
+    }
 
     // Prevent toogleView() events during restore state
-    if (d->DockManager->isRestoringState())
-    {
-        return;
-    }
-
-	// Only a close operation should propagate hide->toggleView(false) to
-	// child dock widgets. Generic hide/show cycles (e.g. from platform or
-	// embedded native content) must not change dock open/closed state.
-	if (!d->HideContentOnNextHide)
-	{
-		return;
-	}
-	d->HideContentOnNextHide = false;
-
-	if ( d->AutoHideChildren )
-	{
-		d->Hiding = true;
-		for ( auto DockArea : d->DockContainer->openedDockAreas() )
+    if (d->DockManager->isRestoringState())
+    {
+        return;
+    }
+
+	// Only a close operation should propagate hide->toggleView(false) to
+	// child dock widgets. Generic hide/show cycles (e.g. from platform or
+	// embedded native content) must not change dock open/closed state.
+	if (!d->HideContentOnNextHide)
+	{
+		return;
+	}
+	d->HideContentOnNextHide = false;
+
+	if ( d->AutoHideChildren )
+	{
+		d->Hiding = true;
+		for ( auto DockArea : d->DockContainer->openedDockAreas() )
 		{
 			for ( auto DockWidget : DockArea->openedDockWidgets() )
 			{
@@ -1220,8 +1223,9 @@ void CFloatingDockContainer::finishDropOperation()
 	if (d->DockManager)
 	{
 		d->DockManager->removeFloatingWidget(this);
-		d->DockManager->removeDockContainer(this->dockContainer());
+		d->DockManager.clear();
 	}
+	this->dockContainer()->removeFromDockManager();
 }
 
 //============================================================================