Update the internal state of the MovePieceInteractor when pieces are merged.

This fixes the only known (and indeed quite annoying) crash in Palapeli.

svn path=/trunk/KDE/kdegames/palapeli/; revision=1119155

src/engine/interactors.cpp

@@ -47,7 +47,6 @@ static QGraphicsItem* findSelectableItemAt(const QPointF& scenePos, QGraphicsSce
 
 void Palapeli::MovePieceInteractor::determineSelectedItems(QGraphicsItem* clickedItem, Palapeli::Piece* clickedPiece)
 {
-	m_currentItems.clear();
 	m_currentPieces.clear();
 	const QList<QGraphicsItem*> selectedItems = clickedItem->scene()->selectedItems();
 	if (clickedItem->isSelected())
@@ -57,10 +56,7 @@ void Palapeli::MovePieceInteractor::determineSelectedItems(QGraphicsItem* clicke
 		{
 			Palapeli::Piece* selectedPiece = Palapeli::Piece::fromSelectedItem(selectedItem);
 			if (selectedPiece)
-			{
-				m_currentItems << selectedItem;
 				m_currentPieces << selectedPiece;
-			}
 		}
 		//NOTE: clickedItem is in the list selectedItems, so it need not be handled separately.
 	}
@@ -70,7 +66,6 @@ void Palapeli::MovePieceInteractor::determineSelectedItems(QGraphicsItem* clicke
 		foreach (QGraphicsItem* selectedItem, selectedItems)
 			selectedItem->setSelected(false);
 		clickedItem->setSelected(true);
-		m_currentItems << clickedItem;
 		m_currentPieces << clickedPiece;
 	}
 }
@@ -88,10 +83,12 @@ bool Palapeli::MovePieceInteractor::startInteraction(const Palapeli::MouseEvent&
 	//start moving this piece
 	determineSelectedItems(selectableItemUnderMouse, piece);
 	m_baseScenePosition = event.scenePos;
+	m_currentOffset = QPointF();
 	m_basePositions.clear();
 	foreach(Palapeli::Piece* piece, m_currentPieces)
 	{
 		m_basePositions << piece->pos();
+		connect(piece, SIGNAL(replacedBy(Palapeli::Piece*)), SLOT(pieceReplacedBy(Palapeli::Piece*)), Qt::DirectConnection);
 		piece->beginMove();
 	}
 	return true;
@@ -99,19 +96,37 @@ bool Palapeli::MovePieceInteractor::startInteraction(const Palapeli::MouseEvent&
 
 void Palapeli::MovePieceInteractor::continueInteraction(const Palapeli::MouseEvent& event)
 {
+	m_currentOffset = event.scenePos - m_baseScenePosition;
 	for (int i = 0; i < m_currentPieces.count(); ++i)
 	{
-		m_currentPieces[i]->setPos(m_basePositions[i] + event.scenePos - m_baseScenePosition);
+		m_currentPieces[i]->setPos(m_basePositions[i] + m_currentOffset);
 		m_currentPieces[i]->doMove();
 	}
 }
 
+void Palapeli::MovePieceInteractor::pieceReplacedBy(Palapeli::Piece* replacement)
+{
+	//This slot is triggered when a MergeGroup replaces one of the m_currentPieces by a new piece.
+	//remove old piece from data structures
+	int index = m_currentPieces.indexOf(reinterpret_cast<Palapeli::Piece*>(sender()));
+	m_currentPieces.removeAt(index);
+	m_basePositions.removeAt(index);
+	//add new piece (might not always be necessary, if the new piece replaces more than one of the selected pieces)
+	if (!m_currentPieces.contains(replacement))
+	{
+		m_currentPieces << replacement;
+		m_basePositions << replacement->pos() - m_currentOffset;
+	}
+}
+
 void Palapeli::MovePieceInteractor::stopInteraction(const Palapeli::MouseEvent& event)
 {
 	Q_UNUSED(event)
 	foreach(Palapeli::Piece* piece, m_currentPieces)
+	{
+		disconnect(piece, 0, this, 0);
 		piece->endMove();
-	m_currentItems.clear();
+	}
 	m_currentPieces.clear();
 }
 
@@ -334,3 +349,5 @@ bool Palapeli::ToggleConstraintInteractor::startInteraction(const Palapeli::Mous
 }
 
 //END Palapeli::ToggleConstraintInteractor
+
+#include "interactors.moc"

src/engine/interactors.h

@@ -30,21 +30,23 @@ namespace Palapeli
 	//This interactor is assigned to LeftButton;NoModifier by default.
 	//1. When you click on and drag a selected piece, all selected pieces are moved.
 	//2. When you click on and drag an unselected piece, all other pieces are deselected, the clicked piece is selected and moved.
-	class MovePieceInteractor : public Palapeli::Interactor
+	class MovePieceInteractor : public QObject, public Palapeli::Interactor
 	{
+		Q_OBJECT
 		public:
 			MovePieceInteractor(QGraphicsView* view);
 		protected:
 			virtual bool startInteraction(const Palapeli::MouseEvent& event);
 			virtual void continueInteraction(const Palapeli::MouseEvent& event);
 			virtual void stopInteraction(const Palapeli::MouseEvent& event);
+		protected Q_SLOTS:
+			void pieceReplacedBy(Palapeli::Piece* replacement);
 		private:
 			Palapeli::Piece* findPieceForItem(QGraphicsItem* mouseInteractingItem) const;
 			void determineSelectedItems(QGraphicsItem* clickedItem, Palapeli::Piece* clickedPiece);
 
-			QList<QGraphicsItem*> m_currentItems; //the item which accepts the events
-			QList<Palapeli::Piece*> m_currentPieces; //the piece for this item
-			QPointF m_baseScenePosition;
+			QList<Palapeli::Piece*> m_currentPieces;
+			QPointF m_baseScenePosition, m_currentOffset;
 			QList<QPointF> m_basePositions;
 	};
 

src/engine/mergegroup.cpp

@@ -151,7 +151,7 @@ void Palapeli::MergeGroup::createMergedPiece()
 		if (piece->isSelected())
 			m_mergedPiece->setSelected(true);
 		m_mergedPiece->setZValue(qMax(m_mergedPiece->zValue(), piece->zValue()));
-		delete piece;
+		piece->announceReplaced(m_mergedPiece); //make sure that interactors know about the change, and delete the piece
 	}
 	m_mergedPiece->rewriteLogicalNeighbors(m_pieces, 0); //0 = these neighbors should be dropped
 	foreach (Palapeli::Piece* logicalNeighbor, m_mergedPiece->logicalNeighbors())

src/engine/piece.cpp

@@ -165,6 +165,12 @@ void Palapeli::Piece::rewriteLogicalNeighbors(const QList<Palapeli::Piece*>& old
 		m_logicalNeighbors += newPiece;
 }
 
+void Palapeli::Piece::announceReplaced(Palapeli::Piece* replacement)
+{
+	emit replacedBy(replacement);
+	delete this;
+}
+
 void Palapeli::Piece::addAtomicSize(const QSize& size)
 {
 	m_atomicSize = m_atomicSize.expandedTo(size);

src/engine/piece.h

@@ -63,8 +63,11 @@ namespace Palapeli
 
 			///When piece instances have been replaced by other piece instances, this method can be used to update the internal data structures of their logical neighbors.
 			void rewriteLogicalNeighbors(const QList<Palapeli::Piece*>& oldPieces, Palapeli::Piece* newPiece);
+			///Call this when this piece instance has been replaced by another piece instance. This will also delete this instance.
+			void announceReplaced(Palapeli::Piece* replacement);
 		Q_SIGNALS:
 			void moved();
+			void replacedBy(Palapeli::Piece* newPiece);
 		protected:
 			friend class MovePieceInteractor;
 			void beginMove();