Disable inter-window drag&drop.

src/app/puzzle/carousel/vpcarrousel.cpp

@@ -226,6 +226,12 @@ void VPCarrousel::on_ActivePieceListChanged(int index)
     RefreshSheetNames();
 }
 
+//---------------------------------------------------------------------------------------------------------------------
+VPLayoutWeakPtr VPCarrousel::Layout() const
+{
+    return m_layout;
+}
+
 //---------------------------------------------------------------------------------------------------------------------
 void VPCarrousel::SetOrientation(Qt::Orientation orientation)
 {

src/app/puzzle/carousel/vpcarrousel.h

@@ -76,6 +76,8 @@ public:
      */
     void Clear();
 
+    VPLayoutWeakPtr Layout() const;
+
 public slots:
     /**
      * @brief Refresh Refreshes the content of the carrousel

src/app/puzzle/carousel/vpcarrouselpiecelist.cpp

@@ -137,9 +137,20 @@ void VPCarrouselPieceList::startDrag(Qt::DropActions supportedActions)
     {
         auto *pieceItem = static_cast<VPCarrouselPiece *> (_item);
 
+        if (m_carrousel == nullptr)
+        {
+            return;
+        }
+
+        VPLayoutPtr layout = m_carrousel->Layout().toStrongRef();
+        if (layout.isNull())
+        {
+            return;
+        }
+
         // starts the dragging
         auto *drag = new QDrag(this);
-        auto *mimeData = new VPMimeDataPiece();
+        auto *mimeData = new VPMimeDataPiece(layout->Uuid());
         VPPiecePtr piece = pieceItem->GetPiece();
         mimeData->SetPiecePtr(piece);
 

src/app/puzzle/carousel/vpmimedatapiece.cpp

@@ -35,6 +35,11 @@
 
 const QString VPMimeDataPiece::mineFormatPiecePtr = QStringLiteral("application/vnd.puzzle.piece.ptr");
 
+//---------------------------------------------------------------------------------------------------------------------
+VPMimeDataPiece::VPMimeDataPiece(const QUuid &layoutUuid)
+    :m_layoutUuid(layoutUuid)
+{}
+
 //---------------------------------------------------------------------------------------------------------------------
 auto VPMimeDataPiece::formats() const -> QStringList
 {
@@ -65,3 +70,9 @@ auto VPMimeDataPiece::DragCursor(const QPixmap &piecePixmap) -> QPixmap
     painter.end();
     return dragCursor;
 }
+
+//---------------------------------------------------------------------------------------------------------------------
+const QUuid &VPMimeDataPiece::LayoutUuid() const
+{
+    return m_layoutUuid;
+}

src/app/puzzle/carousel/vpmimedatapiece.h

@@ -31,6 +31,7 @@
 
 #include <QMimeData>
 #include <QSharedPointer>
+#include <QUuid>
 
 #include "../layout/layoutdef.h"
 
@@ -39,7 +40,7 @@ class VPMimeDataPiece : public QMimeData
     Q_OBJECT
 
 public:
-    VPMimeDataPiece() = default;
+    VPMimeDataPiece(const QUuid &layoutUuid);
     virtual ~VPMimeDataPiece() = default;
 
     virtual auto formats() const -> QStringList override;
@@ -60,10 +61,14 @@ public:
 
     static const QString mineFormatPiecePtr;
 
+    const QUuid &LayoutUuid() const;
+
 private:
     Q_DISABLE_COPY(VPMimeDataPiece)
 
     VPPieceWeakPtr m_piece{};
+
+    QUuid m_layoutUuid;
 };
 
 #endif // VPMIMEDATAPIECE_H

src/app/puzzle/layout/vplayout.cpp

@@ -119,6 +119,12 @@ void VPLayout::AddPiece(const VPPiecePtr &piece)
     }
 }
 
+//---------------------------------------------------------------------------------------------------------------------
+const QUuid &VPLayout::Uuid() const
+{
+    return m_uuid;
+}
+
 //---------------------------------------------------------------------------------------------------------------------
 VPTileFactory *VPLayout::TileFactory() const
 {

src/app/puzzle/layout/vplayout.h

@@ -30,6 +30,7 @@
 
 #include <QList>
 #include <QMap>
+#include <QUuid>
 
 #include "def.h"
 #include "vplayoutsettings.h"
@@ -99,6 +100,8 @@ public:
 
     auto IsSheetsUniform() const -> bool;
 
+    const QUuid &Uuid() const;
+
 signals:
     void PieceSheetChanged(const VPPiecePtr &piece);
     void ActiveSheetChanged(const VPSheetPtr &focusedSheet);
@@ -129,6 +132,8 @@ private:
     QUndoStack *m_undoStack;
 
     VPTileFactory *m_tileFactory{nullptr};
+
+    QUuid m_uuid{QUuid::createUuid()};
 };
 
 Q_DECLARE_METATYPE(VPLayoutPtr)

src/app/puzzle/scene/vpmaingraphicsview.cpp

@@ -121,8 +121,18 @@ void VPMainGraphicsView::dragEnterEvent(QDragEnterEvent *event)
 
     if(mime->hasFormat(VPMimeDataPiece::mineFormatPiecePtr))
     {
-        qCDebug(pMainGraphicsView(), "drag enter");
+        VPLayoutPtr layout = m_layout.toStrongRef();
-        event->acceptProposedAction();
+        if (layout.isNull())
+        {
+            return;
+        }
+
+        const auto *mimePiece = qobject_cast<const VPMimeDataPiece *> (mime);
+        if (mimePiece != nullptr && mimePiece->LayoutUuid() == layout->Uuid())
+        {
+            qCDebug(pMainGraphicsView(), "drag enter");
+            event->acceptProposedAction();
+        }
     }
 }
 
@@ -133,7 +143,17 @@ void VPMainGraphicsView::dragMoveEvent(QDragMoveEvent *event)
 
     if(mime->hasFormat(VPMimeDataPiece::mineFormatPiecePtr))
     {
-        event->acceptProposedAction();
+        VPLayoutPtr layout = m_layout.toStrongRef();
+        if (layout.isNull())
+        {
+            return;
+        }
+
+        const auto *mimePiece = qobject_cast<const VPMimeDataPiece *> (mime);
+        if (mimePiece != nullptr && mimePiece->LayoutUuid() == layout->Uuid())
+        {
+            event->acceptProposedAction();
+        }
     }
 }
 
@@ -152,17 +172,22 @@ void VPMainGraphicsView::dropEvent(QDropEvent *event)
 
     if(mime->hasFormat(VPMimeDataPiece::mineFormatPiecePtr))
     {
+        VPLayoutPtr layout = m_layout.toStrongRef();
+        if (layout.isNull())
+        {
+            return;
+        }
+
         const auto *mimePiece = qobject_cast<const VPMimeDataPiece *> (mime);
 
+        if (mimePiece == nullptr || mimePiece->LayoutUuid() != layout->Uuid())
+        {
+            return;
+        }
+
         VPPiecePtr piece = mimePiece->GetPiecePtr();
         if(not piece.isNull())
         {
-            VPLayoutPtr layout = m_layout.toStrongRef();
-            if (layout.isNull())
-            {
-                return;
-            }
-
             qCDebug(pMainGraphicsView(), "element dropped, %s", qUtf8Printable(piece->GetName()));
             event->acceptProposedAction();