Added support for dropping dock widget to a certain tab postion of a dock area

src/DockAreaTabBar.cpp

@@ -504,6 +504,31 @@ QSize CDockAreaTabBar::sizeHint() const
 	return d->TabsContainerWidget->sizeHint();
 }
 
+
+//===========================================================================
+int CDockAreaTabBar::tabAt(const QPoint& Pos) const
+{
+	if (!isVisible())
+	{
+		return -2;
+	}
+
+	if (Pos.x() < tab(0)->geometry().x())
+	{
+		return -1;
+	}
+
+	for (int i = 0; i < count(); ++i)
+	{
+		if (tab(i)->geometry().contains(Pos))
+		{
+			return i;
+		}
+	}
+
+	return count();
+}
+
 } // namespace ads
 
 

src/DockAreaTabBar.h

@@ -113,6 +113,14 @@ public:
 	 */
 	CDockWidgetTab* tab(int Index) const;
 
+	/**
+	 * Returns the tab at the given position.
+	 * Returns -1 if the position is left of the first tab and count() if the
+	 * position is right of the last tab. Returns -2 to indicate an invalid
+	 * value.
+	 */
+	int tabAt(const QPoint& Pos) const;
+
 	/**
 	 * Filters the tab widget events
 	 */

src/DockContainerWidget.cpp

@@ -190,19 +190,20 @@ public:
 	 * Creates a new tab for a widget dropped into the center of a section
 	 */
 	void dropIntoCenterOfSection(CFloatingDockContainer* FloatingWidget,
-		CDockAreaWidget* TargetArea);
+		CDockAreaWidget* TargetArea, int TabIndex = -2);
 
 	/**
 	 * Drop floating widget into dock area
 	 */
 	void dropIntoSection(CFloatingDockContainer* FloatingWidget,
-		CDockAreaWidget* TargetArea, DockWidgetArea area);
+		CDockAreaWidget* TargetArea, DockWidgetArea area, int TabIndex = -2);
 
 	/**
 	 * Moves the dock widget or dock area given in Widget parameter to a
 	 * new dock widget area
 	 */
-	void moveToNewSection(QWidget* Widget, CDockAreaWidget* TargetArea, DockWidgetArea area);
+	void moveToNewSection(QWidget* Widget, CDockAreaWidget* TargetArea, DockWidgetArea area,
+		int TabIndex = -2);
 
 	/**
 	 * Moves the dock widget or dock area given in Widget parameter to a
@@ -213,7 +214,7 @@ public:
 	/**
 	 * Creates a new tab for a widget dropped into the center of a section
 	 */
-	void moveIntoCenterOfSection(QWidget* Widget, CDockAreaWidget* TargetArea);
+	void moveIntoCenterOfSection(QWidget* Widget, CDockAreaWidget* TargetArea, int TabIndex = -2);
 
 	/**
 	 * Moves the dock widget or dock area given in Widget parameter to
@@ -535,12 +536,13 @@ void DockContainerWidgetPrivate::dropIntoAutoHideSideBar(CFloatingDockContainer*
 
 //============================================================================
 void DockContainerWidgetPrivate::dropIntoCenterOfSection(
-	CFloatingDockContainer* FloatingWidget, CDockAreaWidget* TargetArea)
+	CFloatingDockContainer* FloatingWidget, CDockAreaWidget* TargetArea, int TabIndex)
 {
 	CDockContainerWidget* FloatingContainer = FloatingWidget->dockContainer();
 	auto NewDockWidgets = FloatingContainer->dockWidgets();
 	auto TopLevelDockArea = FloatingContainer->topLevelDockArea();
 	int NewCurrentIndex = -1;
+	TabIndex = (TabIndex < 0) ? 0 : TabIndex;
 
 	// If the floating widget contains only one single dock are, then the
 	// current dock widget of the dock area will also be the future current
@@ -553,7 +555,7 @@ void DockContainerWidgetPrivate::dropIntoCenterOfSection(
 	for (int i = 0; i < NewDockWidgets.count(); ++i)
 	{
 		CDockWidget* DockWidget = NewDockWidgets[i];
-		TargetArea->insertDockWidget(i, DockWidget, false);
+		TargetArea->insertDockWidget(TabIndex + i, DockWidget, false);
 		// If the floating widget contains multiple visible dock areas, then we
 		// simply pick the first visible open dock widget and make it
 		// the current one.
@@ -562,7 +564,7 @@ void DockContainerWidgetPrivate::dropIntoCenterOfSection(
 			NewCurrentIndex = i;
 		}
 	}
-	TargetArea->setCurrentIndex(NewCurrentIndex);
+	TargetArea->setCurrentIndex(NewCurrentIndex + TabIndex);
 	TargetArea->updateTitleBarVisibility();
 	return;
 }
@@ -570,13 +572,14 @@ void DockContainerWidgetPrivate::dropIntoCenterOfSection(
 
 //============================================================================
 void DockContainerWidgetPrivate::dropIntoSection(CFloatingDockContainer* FloatingWidget,
-		CDockAreaWidget* TargetArea, DockWidgetArea area)
+		CDockAreaWidget* TargetArea, DockWidgetArea area, int TabIndex)
 {
+	qDebug() << "DockContainerWidgetPrivate::dropIntoSection TabIndex: " << TabIndex;
 	// Dropping into center means all dock widgets in the dropped floating
 	// widget will become tabs of the drop area
 	if (CenterDockWidgetArea == area)
 	{
-		dropIntoCenterOfSection(FloatingWidget, TargetArea);
+		dropIntoCenterOfSection(FloatingWidget, TargetArea, TabIndex);
 		return;
 	}
 
@@ -666,11 +669,15 @@ void DockContainerWidgetPrivate::dropIntoSection(CFloatingDockContainer* Floatin
 
 
 //============================================================================
-void DockContainerWidgetPrivate::moveIntoCenterOfSection(QWidget* Widget, CDockAreaWidget* TargetArea)
+void DockContainerWidgetPrivate::moveIntoCenterOfSection(QWidget* Widget, CDockAreaWidget* TargetArea,
+	int TabIndex)
 {
+	qDebug() << "DockContainerWidgetPrivate::moveIntoCenterOfSection TabIndex: "
+		<< TabIndex;
 	auto DroppedDockWidget = qobject_cast<CDockWidget*>(Widget);
 	auto DroppedArea = qobject_cast<CDockAreaWidget*>(Widget);
 
+	TabIndex = (TabIndex < 0) ? 0 : TabIndex;
 	if (DroppedDockWidget)
 	{
 		CDockAreaWidget* OldDockArea = DroppedDockWidget->dockAreaWidget();
@@ -683,7 +690,7 @@ void DockContainerWidgetPrivate::moveIntoCenterOfSection(QWidget* Widget, CDockA
 		{
 			OldDockArea->removeDockWidget(DroppedDockWidget);
 		}
-		TargetArea->insertDockWidget(0, DroppedDockWidget, true);
+		TargetArea->insertDockWidget(TabIndex, DroppedDockWidget, true);
 	}
 	else
 	{
@@ -692,9 +699,9 @@ void DockContainerWidgetPrivate::moveIntoCenterOfSection(QWidget* Widget, CDockA
 		for (int i = 0; i < NewDockWidgets.count(); ++i)
 		{
 			CDockWidget* DockWidget = NewDockWidgets[i];
-			TargetArea->insertDockWidget(i, DockWidget, false);
+			TargetArea->insertDockWidget(TabIndex + i, DockWidget, false);
 		}
-		TargetArea->setCurrentIndex(NewCurrentIndex);
+		TargetArea->setCurrentIndex(TabIndex + NewCurrentIndex);
 		DroppedArea->dockContainer()->removeDockArea(DroppedArea);
 		DroppedArea->deleteLater();
 	}
@@ -705,13 +712,16 @@ void DockContainerWidgetPrivate::moveIntoCenterOfSection(QWidget* Widget, CDockA
 
 
 //============================================================================
-void DockContainerWidgetPrivate::moveToNewSection(QWidget* Widget, CDockAreaWidget* TargetArea, DockWidgetArea area)
+void DockContainerWidgetPrivate::moveToNewSection(QWidget* Widget, CDockAreaWidget* TargetArea, DockWidgetArea area,
+	int TabIndex)
 {
+	qDebug() << "DockContainerWidgetPrivate::moveToNewSection TabIndex: "
+		<< TabIndex;
 	// Dropping into center means all dock widgets in the dropped floating
 	// widget will become tabs of the drop area
 	if (CenterDockWidgetArea == area)
 	{
-		moveIntoCenterOfSection(Widget, TargetArea);
+		moveIntoCenterOfSection(Widget, TargetArea, TabIndex);
 		return;
 	}
 
@@ -1705,7 +1715,6 @@ void CDockContainerWidget::dropFloatingWidget(CFloatingDockContainer* FloatingWi
 	bool Dropped = false;
 
 	CDockAreaWidget* DockArea = dockAreaAt(TargetPos);
-	std::cout << "DockArea: " << DockArea << " dropArea: " << dropArea << std::endl;
 	if (DockArea)
 	{
 		auto dropOverlay = d->DockManager->dockAreaOverlay();
@@ -1720,7 +1729,8 @@ void CDockContainerWidget::dropFloatingWidget(CFloatingDockContainer* FloatingWi
 		if (dropArea != InvalidDockWidgetArea)
 		{
             ADS_PRINT("Dock Area Drop Content: " << dropArea);
-			d->dropIntoSection(FloatingWidget, DockArea, dropArea);
+            int TabIndex = d->DockManager->dockAreaOverlay()->tabIndexUnderCursor();
+			d->dropIntoSection(FloatingWidget, DockArea, dropArea, TabIndex);
 			Dropped = true;
 		}
 	}
@@ -1773,12 +1783,14 @@ void CDockContainerWidget::dropFloatingWidget(CFloatingDockContainer* FloatingWi
 
 
 //============================================================================
-void CDockContainerWidget::dropWidget(QWidget* Widget, DockWidgetArea DropArea, CDockAreaWidget* TargetAreaWidget)
+void CDockContainerWidget::dropWidget(QWidget* Widget, DockWidgetArea DropArea, CDockAreaWidget* TargetAreaWidget,
+	int TabIndex)
 {
+	qDebug() << "CDockContainerWidget::dropWidget TabIndex: " << TabIndex;
     CDockWidget* SingleDockWidget = topLevelDockWidget();
 	if (TargetAreaWidget)
 	{
-		d->moveToNewSection(Widget, TargetAreaWidget, DropArea);
+		d->moveToNewSection(Widget, TargetAreaWidget, DropArea, TabIndex);
 	}
 	else if (internal::isSideBarArea(DropArea))
 	{

src/DockContainerWidget.h

@@ -132,7 +132,8 @@ protected:
 	 * a nullptr, then the DropArea indicates the drop area in the given
 	 * TargetAreaWidget
 	 */
-	void dropWidget(QWidget* Widget, DockWidgetArea DropArea, CDockAreaWidget* TargetAreaWidget);
+	void dropWidget(QWidget* Widget, DockWidgetArea DropArea, CDockAreaWidget* TargetAreaWidget,
+		int TabIndex = -2);
 
 	/**
 	 * Adds the given dock area to this container widget

src/DockOverlay.cpp

@@ -41,6 +41,7 @@
 #include "DockContainerWidget.h"
 #include "AutoHideSideBar.h"
 #include "DockManager.h"
+#include "DockAreaTabBar.h"
 
 #include <iostream>
 
@@ -48,6 +49,7 @@ namespace ads
 {
 static const int AutoHideAreaWidth = 32;
 static const int AutoHideAreaMouseZone = 8;
+static const int InvalidTabIndex = -2;
 
 /**
  * Private data class of CDockOverlay
@@ -62,6 +64,7 @@ struct DockOverlayPrivate
 	bool DropPreviewEnabled = true;
 	CDockOverlay::eMode Mode = CDockOverlay::ModeDockAreaOverlay;
 	QRect DropAreaRect;
+	int TabIndex = InvalidTabIndex;
 
 	/**
 	 * Private data constructor
@@ -456,6 +459,7 @@ DockWidgetAreas CDockOverlay::allowedAreas() const
 //============================================================================
 DockWidgetArea CDockOverlay::dropAreaUnderCursor() const
 {
+	d->TabIndex = InvalidTabIndex;
 	if (!d->TargetWidget)
 	{
 		return InvalidDockWidgetArea;
@@ -503,10 +507,13 @@ DockWidgetArea CDockOverlay::dropAreaUnderCursor() const
 		return Result;
 	}
 
+	auto CursorPos = QCursor::pos();
 	if (DockArea->allowedAreas().testFlag(CenterDockWidgetArea)
 	 && !DockArea->titleBar()->isHidden()
-	 && DockArea->titleBarGeometry().contains(DockArea->mapFromGlobal(QCursor::pos())))
+	 && DockArea->titleBarGeometry().contains(DockArea->mapFromGlobal(CursorPos)))
 	{
+		auto TabBar = DockArea->titleBar()->tabBar();
+		d->TabIndex = TabBar->tabAt(TabBar->mapFromGlobal(CursorPos));
 		return CenterDockWidgetArea;
 	}
 
@@ -514,6 +521,13 @@ DockWidgetArea CDockOverlay::dropAreaUnderCursor() const
 }
 
 
+//============================================================================
+int CDockOverlay::tabIndexUnderCursor() const
+{
+	return d->TabIndex;
+}
+
+
 //============================================================================
 DockWidgetArea CDockOverlay::visibleDropAreaUnderCursor() const
 {

src/DockOverlay.h

@@ -87,6 +87,17 @@ public:
 	 */
 	DockWidgetArea dropAreaUnderCursor() const;
 
+	/**
+	 * If the drop area is the CenterDockWidgetArea or a sidebar area,
+	 * then this function returns the index of the tab under cursor.
+	 * Call this function after call to dropAreaUnderCursor() because this
+	 * function updates the tab index.
+	 * A value of -1 indicates a position before the first tab and a value of
+	 * tabCount() indicates a position behind the last tab.
+	 * A value of -2 indicates an valid value
+	 */
+	int tabIndexUnderCursor() const;
+
 	/**
 	 * This function returns the same like dropAreaUnderCursor() if this
 	 * overlay is not hidden and if drop preview is enabled and returns

src/FloatingDragPreview.cpp

@@ -396,7 +396,8 @@ void CFloatingDragPreview::finishDragging()
 	}
 	else if (DockDropArea != InvalidDockWidgetArea)
 	{
-		d->DropContainer->dropWidget(d->Content, DockDropArea, d->DropContainer->dockAreaAt(QCursor::pos()));
+		d->DropContainer->dropWidget(d->Content, DockDropArea, d->DropContainer->dockAreaAt(QCursor::pos()),
+			d->DockManager->dockAreaOverlay()->tabIndexUnderCursor());
 	}
 	else if (ContainerDropArea != InvalidDockWidgetArea)
 	{