diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,7 +28,7 @@
     Crash
     KHtml
     Config
-    KDELibs4Support
+    IconThemes
     NewStuff
     Plotting
 )
diff --git a/step/CMakeLists.txt b/step/CMakeLists.txt
--- a/step/CMakeLists.txt
+++ b/step/CMakeLists.txt
@@ -54,6 +54,9 @@
     add_definitions(${QALCULATE_CFLAGS})
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${KDE4_ENABLE_EXCEPTIONS}")
     set(qalculate_LIBS ${QALCULATE_LIBRARIES} ${CLN_LIBRARIES})
+    # To compile with libcln
+    string (REPLACE "-fno-exceptions" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    add_definitions (-fexceptions)
 endif(STEP_WITH_QALCULATE)
 
 ki18n_wrap_ui( step_SRCS ${step_UIS} )
@@ -69,11 +72,12 @@
 target_link_libraries(step
     stepcore
     KF5::Crash
+    KF5::IconThemes
     KF5::KHtml
     KF5::Plotting
     KF5::NewStuff
-    KF5::KDELibs4Support
     Qt5::OpenGL
+    Qt5::Widgets
     ${qalculate_LIBS})
 
 install(TARGETS step ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})
diff --git a/step/gascreationdialog.h b/step/gascreationdialog.h
--- a/step/gascreationdialog.h
+++ b/step/gascreationdialog.h
@@ -38,7 +38,7 @@
     
 public:
     GasCreationDialog(GasMenuHandler* handler, StepCore::Gas *gas,
-		      QWidget *parent=0, Qt::WFlags flags=0);
+		      QWidget *parent=0);
 
     Ui::WidgetCreateGasParticles *ui();
 
diff --git a/step/gascreationdialog.cc b/step/gascreationdialog.cc
--- a/step/gascreationdialog.cc
+++ b/step/gascreationdialog.cc
@@ -35,8 +35,8 @@
 
 
 GasCreationDialog::GasCreationDialog(GasMenuHandler* handler, StepCore::Gas *gas,
-				     QWidget *parent, Qt::WFlags flags)
-    : QDialog(parent, flags)
+				     QWidget *parent)
+    : QDialog(parent)
     , _gas(gas)
     , _handler(handler)
 {
diff --git a/step/gasgraphics.cc b/step/gasgraphics.cc
--- a/step/gasgraphics.cc
+++ b/step/gasgraphics.cc
@@ -179,12 +179,12 @@
     setFlag(QGraphicsItem::ItemIsMovable);
     //setExclusiveMoving(true);
     //setFlag(QGraphicsItem::ItemIsMovable);
-    //setAcceptsHoverEvents(true);
+    //setAcceptHoverEvents(true);
     //_centerHandler = new ArrowHandlerGraphicsItem(item, worldModel, this,
     //                        _item->metaObject()->property("measureRectCenter"));
     //_centerHandler->setVisible(false);
     setZValue(REGION_ZVALUE);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
     setOnHoverHandlerEnabled(true);
 }
 
diff --git a/step/infobrowser.h b/step/infobrowser.h
--- a/step/infobrowser.h
+++ b/step/infobrowser.h
@@ -37,7 +37,7 @@
     Q_OBJECT
 
 public:
-    explicit InfoBrowser(WorldModel* worldModel, QWidget* parent = 0, Qt::WindowFlags flags = {});
+    explicit InfoBrowser(WorldModel* worldModel, QWidget* parent = 0);
 
 public slots:
     void openUrl(const QUrl& url, bool clearHistory = false, bool fromHistory = false);
diff --git a/step/infobrowser.cc b/step/infobrowser.cc
--- a/step/infobrowser.cc
+++ b/step/infobrowser.cc
@@ -35,8 +35,8 @@
 #include <QIcon>
 #include <QStandardPaths>
 
-InfoBrowser::InfoBrowser(WorldModel* worldModel, QWidget* parent, Qt::WindowFlags flags)
-    : QDockWidget(i18n("Context info"), parent, flags),
+InfoBrowser::InfoBrowser(WorldModel* worldModel, QWidget* parent)
+    : QDockWidget(i18n("Context info"), parent),
       _worldModel(worldModel), _wikiJob(NULL), _wikiFromHistory(false), _selectionChanged(false)
 {
     QWidget* widget = new QWidget(this);
diff --git a/step/itempalette.h b/step/itempalette.h
--- a/step/itempalette.h
+++ b/step/itempalette.h
@@ -37,7 +37,7 @@
     Q_OBJECT
 
 public:
-    explicit ItemPalette(WorldModel* worldModel, QWidget* parent = 0, Qt::WindowFlags flags = {});
+    explicit ItemPalette(WorldModel* worldModel, QWidget* parent = 0);
 
 signals:
     void beginAddItem(const QString& name);
diff --git a/step/itempalette.cc b/step/itempalette.cc
--- a/step/itempalette.cc
+++ b/step/itempalette.cc
@@ -187,8 +187,8 @@
     }
 };
 
-ItemPalette::ItemPalette(WorldModel* worldModel, QWidget* parent, Qt::WindowFlags flags)
-    : QDockWidget(i18n("Palette"), parent, flags), _worldModel(worldModel), _widget(0)
+ItemPalette::ItemPalette(WorldModel* worldModel, QWidget* parent)
+    : QDockWidget(i18n("Palette"), parent), _worldModel(worldModel), _widget(0)
 {
     setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
     //setFeatures(QDockWidget::DockWidgetMovable | QDockWidget::DockWidgetFloatable);
diff --git a/step/mainwindow.cc b/step/mainwindow.cc
--- a/step/mainwindow.cc
+++ b/step/mainwindow.cc
@@ -44,10 +44,8 @@
 #include <KMessageBox>
 #include <KRecentFilesAction>
 #include <KStandardAction>
-#include <KStatusBar>
 #include <KToolBarPopupAction>
-
-#include <knewstuff3/downloaddialog.h>
+#include <KNS3/DownloadDialog>
 
 #include <QAction>
 #include <QDir>
@@ -59,6 +57,7 @@
 #include <QKeySequence>
 #include <QMenu>
 #include <QStandardPaths>
+#include <QStatusBar>
 #include <QTemporaryFile>
 
 #include <cstdlib>
diff --git a/step/messageframe.h b/step/messageframe.h
--- a/step/messageframe.h
+++ b/step/messageframe.h
@@ -34,7 +34,7 @@
     enum Flag { CloseButton = 1, CloseTimer = 2 };
     Q_DECLARE_FLAGS(Flags, Flag)
 
-    explicit MessageFrame(QWidget* parent = 0, Qt::WindowFlags f = {});
+    explicit MessageFrame(QWidget* parent = 0);
 
     int showMessage(Type type, const QString& text, Flags flags = 0);
     int changeMessage(int id, Type type, const QString& text, Flags flags = 0);
diff --git a/step/messageframe.cc b/step/messageframe.cc
--- a/step/messageframe.cc
+++ b/step/messageframe.cc
@@ -26,8 +26,8 @@
 #include <QTimer>
 #include <QIcon>
 
-MessageFrame::MessageFrame(QWidget* parent, Qt::WindowFlags f)
-    : QFrame(parent, f), _lastId(0)
+MessageFrame::MessageFrame(QWidget* parent)
+    : QFrame(parent), _lastId(0)
 {
     hide();
 
diff --git a/step/particlegraphics.cc b/step/particlegraphics.cc
--- a/step/particlegraphics.cc
+++ b/step/particlegraphics.cc
@@ -31,7 +31,7 @@
     Q_ASSERT(dynamic_cast<StepCore::Particle*>(_item) != NULL);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
     _lastArrowRadius = -1;
     _velocityHandler = new ArrowHandlerGraphicsItem(item, worldModel, this,
                    _item->metaObject()->property("velocity"));
diff --git a/step/polygongraphics.cc b/step/polygongraphics.cc
--- a/step/polygongraphics.cc
+++ b/step/polygongraphics.cc
@@ -38,7 +38,7 @@
     Q_ASSERT(dynamic_cast<StepCore::RigidBody*>(_item) != NULL);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
     _velocityHandler = new ArrowHandlerGraphicsItem(item, worldModel, this,
                    _item->metaObject()->property("velocity"));
     _velocityHandler->setVisible(false);
diff --git a/step/propertiesbrowser.h b/step/propertiesbrowser.h
--- a/step/propertiesbrowser.h
+++ b/step/propertiesbrowser.h
@@ -60,7 +60,7 @@
     Q_OBJECT
 
 public:
-    explicit PropertiesBrowser(WorldModel* worldModel, QWidget* parent = 0, Qt::WindowFlags flags = {});
+    explicit PropertiesBrowser(WorldModel* worldModel, QWidget* parent = 0);
 
 public slots:
     void settingsChanged();
diff --git a/step/propertiesbrowser.cc b/step/propertiesbrowser.cc
--- a/step/propertiesbrowser.cc
+++ b/step/propertiesbrowser.cc
@@ -89,6 +89,7 @@
 
 void PropertiesBrowserModel::setObject(StepCore::Object* object)
 {
+    beginResetModel();
     _object = object;
 
     _subRows.clear();
@@ -111,7 +112,7 @@
         }
     }
 
-    reset();
+    endResetModel();
 }
 
 void PropertiesBrowserModel::emitDataChanged(bool dynamicOnly)
@@ -272,11 +273,12 @@
             }
             if(index.row() == 1 && dynamic_cast<StepCore::Solver*>(_object)) {
                 if(value.toString() != _object->metaObject()->className()) {
+                    beginResetModel();
                     _worldModel->beginMacro(i18n("Change solver type"));
                     _object = _worldModel->newSolver(value.toString() + "Solver");
                     Q_ASSERT(_object != NULL);
                     _worldModel->endMacro();
-                    reset();
+                    endResetModel();
                 }
             } else {
                 const StepCore::MetaProperty* p = _object->metaObject()->property(index.row());
@@ -667,8 +669,8 @@
     return option;
 }
 
-PropertiesBrowser::PropertiesBrowser(WorldModel* worldModel, QWidget* parent, Qt::WindowFlags flags)
-    : QDockWidget(i18n("Properties"), parent, flags)
+PropertiesBrowser::PropertiesBrowser(WorldModel* worldModel, QWidget* parent)
+    : QDockWidget(i18n("Properties"), parent)
 {
     _worldModel = worldModel;
     _propertiesBrowserModel = new PropertiesBrowserModel(worldModel, this);
diff --git a/step/softbodygraphics.cc b/step/softbodygraphics.cc
--- a/step/softbodygraphics.cc
+++ b/step/softbodygraphics.cc
@@ -212,7 +212,7 @@
     Q_ASSERT(dynamic_cast<StepCore::SoftBody*>(_item) != NULL);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
     setZValue(BODY_ZVALUE-1);
     _velocityHandler = new ArrowHandlerGraphicsItem(item, worldModel, this,
                    _item->metaObject()->property("velocity"),
diff --git a/step/stepgraphicsitem.h b/step/stepgraphicsitem.h
--- a/step/stepgraphicsitem.h
+++ b/step/stepgraphicsitem.h
@@ -152,7 +152,7 @@
     bool isOnHoverHandlerEnabled() const { return _onHoverHandlerEnabled; }
 
     /** Set to true in order to enable on-hover handler.
-     *  \note You should also call setAcceptsHoverEvents(true) in order
+     *  \note You should also call setAcceptHoverEvents(true) in order
      *  for on-hover handler to work */
     void setOnHoverHandlerEnabled(bool enabled);
 
diff --git a/step/stepgraphicsitem.cc b/step/stepgraphicsitem.cc
--- a/step/stepgraphicsitem.cc
+++ b/step/stepgraphicsitem.cc
@@ -164,7 +164,7 @@
 void StepGraphicsItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
 {
     // Workaround for bug in Qt
-    if (scene()->itemAt(event->scenePos()) != this) {
+    if (scene()->itemAt(event->scenePos(), QTransform()) != this) {
         event->ignore();
         return;
     }
@@ -185,7 +185,7 @@
 {
     // Workaround for bug in Qt
     if (scene()->mouseGrabberItem() != this &&
-        scene()->itemAt(event->scenePos()) != this) {
+        scene()->itemAt(event->scenePos(), QTransform()) != this) {
         event->ignore();
         return;
     }
@@ -242,7 +242,7 @@
 void StepGraphicsItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 {
     // Workaround for bug in Qt
-    if (scene()->itemAt(event->scenePos()) != this) {
+    if (scene()->itemAt(event->scenePos(), QTransform()) != this) {
         event->ignore();
         return;
     }
@@ -606,7 +606,7 @@
     _deleteTimer->setInterval(500);
     _deleteTimer->setSingleShot(true);
     _deleteTimerEnabled = false;
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
     connect(_deleteTimer, SIGNAL(timeout()), this, SLOT(deleteLater()));
 }
 
diff --git a/step/toolgraphics.cc b/step/toolgraphics.cc
--- a/step/toolgraphics.cc
+++ b/step/toolgraphics.cc
@@ -70,7 +70,6 @@
 #include <KPlotObject>
 #include <KPlotPoint>
 #include <KPlotWidget>
-#include <KProgressDialog>
 #include <KToggleAction>
 #include <KToolBar>
 
@@ -134,7 +133,7 @@
 {
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
 
     _backgroundBrush = Qt::NoBrush;
 
@@ -370,7 +369,7 @@
     Q_ASSERT(dynamic_cast<StepCore::Note*>(_item) != NULL);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
 
     _widget = new QWidget();
     _widget->setPalette(QPalette(Qt::lightGray));
@@ -900,7 +899,7 @@
     Q_ASSERT(dynamic_cast<StepCore::Graph*>(_item) != NULL);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
 
     _plotWidget = new KPlotWidget();
     _plotWidget->setPalette(QPalette(Qt::lightGray));
@@ -1246,7 +1245,7 @@
     Q_ASSERT(dynamic_cast<StepCore::Meter*>(_item) != NULL);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
     setBackgroundBrush(QBrush(Qt::white));
 
     _widget = new QFrame();
@@ -1409,7 +1408,7 @@
     Q_ASSERT(dynamic_cast<StepCore::Controller*>(_item) != NULL);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setFlag(QGraphicsItem::ItemIsMovable);
-    setAcceptsHoverEvents(true);
+    setAcceptHoverEvents(true);
     setBackgroundBrush(QBrush(Qt::white));
 
     _widget = new QWidget();
diff --git a/step/undobrowser.h b/step/undobrowser.h
--- a/step/undobrowser.h
+++ b/step/undobrowser.h
@@ -30,7 +30,7 @@
     Q_OBJECT
 
 public:
-    explicit UndoBrowser(WorldModel* worldModel, QWidget* parent = 0, Qt::WindowFlags flags = {});
+    explicit UndoBrowser(WorldModel* worldModel, QWidget* parent = 0);
 
 public slots:
     void setEmptyLabel(const QString& label);
diff --git a/step/undobrowser.cc b/step/undobrowser.cc
--- a/step/undobrowser.cc
+++ b/step/undobrowser.cc
@@ -24,8 +24,8 @@
 #include <QIcon>
 #include <KLocalizedString>
 
-UndoBrowser::UndoBrowser(WorldModel* worldModel, QWidget* parent, Qt::WindowFlags flags)
-    : QDockWidget(i18n("Undo history"), parent, flags), _worldModel(worldModel)
+UndoBrowser::UndoBrowser(WorldModel* worldModel, QWidget* parent)
+    : QDockWidget(i18n("Undo history"), parent), _worldModel(worldModel)
 {
     _undoView = new QUndoView(_worldModel->undoStack(), this);
     setWidget(_undoView);
diff --git a/step/worldbrowser.h b/step/worldbrowser.h
--- a/step/worldbrowser.h
+++ b/step/worldbrowser.h
@@ -29,7 +29,7 @@
     Q_OBJECT
 
 public:
-    explicit WorldBrowser(WorldModel* worldModel, QWidget* parent = 0, Qt::WindowFlags flags = {});
+    explicit WorldBrowser(WorldModel* worldModel, QWidget* parent = 0);
 
 protected:
     WorldBrowserView* _worldBrowserView;
diff --git a/step/worldbrowser.cc b/step/worldbrowser.cc
--- a/step/worldbrowser.cc
+++ b/step/worldbrowser.cc
@@ -56,8 +56,8 @@
         _macStyle = QApplication::style()->inherits("QMacStyle");
 }
 
-WorldBrowser::WorldBrowser(WorldModel* worldModel, QWidget* parent, Qt::WindowFlags flags)
-    : QDockWidget(i18nc("Object list", "World"), parent, flags)
+WorldBrowser::WorldBrowser(WorldModel* worldModel, QWidget* parent)
+    : QDockWidget(i18nc("Object list", "World"), parent)
 {
     _worldBrowserView = new WorldBrowserView(this);
     _worldBrowserView->header()->hide();
diff --git a/step/worldmodel.cc b/step/worldmodel.cc
--- a/step/worldmodel.cc
+++ b/step/worldmodel.cc
@@ -262,8 +262,9 @@
     PairInt current = indexToPair(_worldModel->_selectionModel->currentIndex());
     */
 
+    _worldModel->beginResetModel();
     _newWorld = _worldModel->_world = new StepCore::World(*_oldWorld);
-    _worldModel->reset();
+    _worldModel->endResetModel();
 
     _startTime = _worldModel->formatProperty(_worldModel->_world, NULL,
                             _worldModel->_world->metaObject()->property("time"),
@@ -286,21 +287,23 @@
 void CommandSimulate::redo()
 {
     if(_newWorld != _worldModel->_world) {
+        _worldModel->beginResetModel();
         _worldModel->_world = _newWorld;
         _worldCopy = _oldWorld;
 
-        _worldModel->reset();
+        _worldModel->endResetModel();
         _worldModel->_selectionModel->setCurrentIndex(
                 _worldModel->worldIndex(), QItemSelectionModel::SelectCurrent);
     }
 }
 
 void CommandSimulate::undo()
 {
+    _worldModel->beginResetModel();
     _worldModel->_world = _oldWorld;
     _worldCopy = _newWorld;
 
-    _worldModel->reset();
+    _worldModel->endResetModel();
     _worldModel->_selectionModel->setCurrentIndex(
             _worldModel->worldIndex(), QItemSelectionModel::SelectCurrent);
 }
@@ -359,6 +362,7 @@
 void WorldModel::resetWorld()
 {
     Q_ASSERT(!isSimulationActive());
+    beginResetModel();
     if(_world->name().isEmpty()) {
         // XXX: check that loaded items has unique names !
         _world->setName(getUniqueName("world"));
@@ -378,7 +382,7 @@
     _undoStack->clear();
 
     _world->doCalcFn();
-    reset();
+    endResetModel();
 
     _selectionModel->setCurrentIndex(worldIndex(), QItemSelectionModel::SelectCurrent);
 
diff --git a/step/worldscene.cc b/step/worldscene.cc
--- a/step/worldscene.cc
+++ b/step/worldscene.cc
@@ -125,8 +125,7 @@
 {
     prepareGeometryChange();
     _viewScale = static_cast<WorldScene*>(scene())->currentViewScale();
-    resetMatrix();
-    scale(1/_viewScale, -1/_viewScale);
+    setTransform(QTransform::fromScale(1/_viewScale, -1/_viewScale), false);
 }
 
 WorldScene::WorldScene(WorldModel* worldModel, QObject* parent)
@@ -230,7 +229,7 @@
 
 void WorldScene::mousePressEvent(QGraphicsSceneMouseEvent* mouseEvent)
 {
-    if(itemAt(mouseEvent->scenePos()) == NULL) {
+    if(itemAt(mouseEvent->scenePos(), QTransform()) == NULL) {
         // XXX: how to easily select World ?
         //_worldModel->selectionModel()->clearSelection();
         _worldModel->selectionModel()->setCurrentIndex(_worldModel->worldIndex(), QItemSelectionModel::Clear);