Fix KTabWidget porting issue

Restore drop on tabs

Reviewed by Albert

shell/shell.cpp

@@ -96,10 +96,12 @@ Shell::Shell( const QString &serializedOptions )
     m_tabWidget->tabBar()->hide();
     m_tabWidget->setDocumentMode( true );
     m_tabWidget->setMovable( true );
+
+    m_tabWidget->setAcceptDrops(true);
+    m_tabWidget->installEventFilter(this);
+
     connect( m_tabWidget, &QTabWidget::currentChanged, this, &Shell::setActiveTab );
     connect( m_tabWidget, &QTabWidget::tabCloseRequested, this, &Shell::closeTab );
-    connect( m_tabWidget, SIGNAL(testCanDecode(const QDragMoveEvent*,bool&)), SLOT(testTabDrop(const QDragMoveEvent*,bool&)) ); // kf5 FIXME DnD
-    connect( m_tabWidget, SIGNAL(receivedDropEvent(QDropEvent*)), SLOT(handleTabDrop(QDropEvent*)) ); // kf5 FIXME DnD
     connect( m_tabWidget->tabBar(), &QTabBar::tabMoved, this, &Shell::moveTabData );
 
     setCentralWidget( m_tabWidget );
@@ -138,6 +140,25 @@ Shell::Shell( const QString &serializedOptions )
   }
 }
 
+bool Shell::eventFilter(QObject *obj, QEvent *event)
+{
+    QDragMoveEvent* dmEvent = dynamic_cast<QDragMoveEvent*>(event);
+    if (dmEvent) {
+        bool accept = dmEvent->mimeData()->hasUrls();
+        event->setAccepted(accept);
+        return accept;
+    }
+
+    QDropEvent* dEvent = dynamic_cast<QDropEvent*>(event);
+    if (dEvent) {
+        const QList<QUrl> list = KUrlMimeData::urlsFromMimeData(dEvent->mimeData());
+        handleDroppedUrls(list);
+        dEvent->setAccepted(true);
+        return true;
+    }
+    return false;
+}
+
 bool Shell::isValid() const
 {
     return m_isValid;
@@ -652,17 +673,6 @@ void Shell::handleDroppedUrls( const QList<QUrl>& urls )
     }
 }
 
-void Shell::testTabDrop( const QDragMoveEvent* event, bool& accept )
-{
-    accept = event->mimeData()->hasUrls();
-}
-
-void Shell::handleTabDrop( QDropEvent* event )
-{
-    const QList<QUrl> list = KUrlMimeData::urlsFromMimeData( event->mimeData() );
-    handleDroppedUrls( list );
-}
-
 void Shell::moveTabData( int from, int to )
 {
    m_tabs.move( from, to );

shell/shell.h

@@ -119,8 +119,6 @@ private slots:
   void closeTab( int tab );
   void activateNextTab();
   void activatePrevTab();
-  void testTabDrop( const QDragMoveEvent* event, bool& accept );
-  void handleTabDrop( QDropEvent* event );
   void moveTabData( int from, int to );
 
   void slotFitWindowToPage( const QSize& pageViewSize, const QSize& pageSize );
@@ -138,6 +136,8 @@ private:
   int  findTabIndex( QObject* sender );
 
 private:
+  bool eventFilter(QObject *obj, QEvent *event) override;
+
   KPluginFactory* m_partFactory;
   KRecentFilesAction* m_recent;
   QStringList m_fileformats;