Enable pan and zoom gestures for the formeditor

Use continuous zoom for mouse-wheel zoom
Directly apply zoom and not by detouring through custom notification
Moved logic related to zooming from the zoom-action into the view

Change-Id: Ib56779f3ea686736cc419aec94d7b5566091fb96
Reviewed-by: Henning Gründl <henning.gruendl@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/CMakeLists.txt

@@ -208,6 +208,7 @@ extend_qtc_plugin(QmlDesigner
     modelnodecontextmenu_helper.cpp modelnodecontextmenu_helper.h
     modelnodeoperations.cpp modelnodeoperations.h
     navigation2d.cpp navigation2d.h
+    gestures.cpp gestures.h
     qmldesignericonprovider.cpp qmldesignericonprovider.h
     selectioncontext.cpp selectioncontext.h
     theme.cpp theme.h

src/plugins/qmldesigner/components/componentcore/componentcore.pri

@@ -5,6 +5,7 @@ SOURCES += addimagesdialog.cpp
 SOURCES += changestyleaction.cpp
 SOURCES += theme.cpp
 SOURCES += findimplementation.cpp
+SOURCES += gestures.cpp
 SOURCES += addsignalhandlerdialog.cpp
 SOURCES += layoutingridlayout.cpp
 SOURCES += abstractactiongroup.cpp
@@ -24,6 +25,7 @@ HEADERS += addimagesdialog.h
 HEADERS += changestyleaction.h
 HEADERS += theme.h
 HEADERS += findimplementation.h
+HEADERS += gestures.h
 HEADERS += addsignalhandlerdialog.h
 HEADERS += layoutingridlayout.h
 HEADERS += abstractactiongroup.h

src/plugins/qmldesigner/components/componentcore/gestures.cpp

@@ -0,0 +1,156 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Design Tooling
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "gestures.h"
+
+#include <QWidget>
+
+namespace QmlDesigner {
+
+Qt::GestureType TwoFingerSwipe::m_type = static_cast<Qt::GestureType>(0);
+
+TwoFingerSwipe::TwoFingerSwipe() {}
+
+Qt::GestureType TwoFingerSwipe::type()
+{
+    return m_type;
+}
+
+void TwoFingerSwipe::registerRecognizer()
+{
+    m_type = QGestureRecognizer::registerRecognizer(new TwoFingerSwipeRecognizer());
+}
+
+QPointF TwoFingerSwipe::direction() const
+{
+    return m_current.center() - m_last.center();
+}
+
+void TwoFingerSwipe::reset()
+{
+    m_start = QLineF();
+    m_current = QLineF();
+    m_last = QLineF();
+}
+
+QGestureRecognizer::Result TwoFingerSwipe::begin(QTouchEvent *event)
+{
+    Q_UNUSED(event);
+    return QGestureRecognizer::MayBeGesture;
+}
+
+QGestureRecognizer::Result TwoFingerSwipe::update(QTouchEvent *event)
+{
+    if (event->touchPoints().size() != 2) {
+        if (state() == Qt::NoGesture)
+            return QGestureRecognizer::Ignore;
+        else
+            return QGestureRecognizer::FinishGesture;
+    }
+
+    QTouchEvent::TouchPoint p0 = event->touchPoints().at(0);
+    QTouchEvent::TouchPoint p1 = event->touchPoints().at(1);
+
+    QLineF line(p0.scenePos(), p1.screenPos());
+
+    if (m_start.isNull()) {
+        m_start = line;
+        m_current = line;
+        m_last = line;
+    } else {
+        auto deltaLength = line.length() - m_current.length();
+        auto deltaCenter = QLineF(line.center(), m_current.center()).length();
+        if (deltaLength > deltaCenter)
+            return QGestureRecognizer::CancelGesture;
+
+        m_last = m_current;
+        m_current = line;
+    }
+
+    setHotSpot(m_current.center());
+
+    return QGestureRecognizer::TriggerGesture;
+}
+
+QGestureRecognizer::Result TwoFingerSwipe::end(QTouchEvent *event)
+{
+    Q_UNUSED(event);
+    bool finish = state() != Qt::NoGesture;
+
+    reset();
+
+    if (finish)
+        return QGestureRecognizer::FinishGesture;
+    else
+        return QGestureRecognizer::CancelGesture;
+}
+
+TwoFingerSwipeRecognizer::TwoFingerSwipeRecognizer()
+    : QGestureRecognizer()
+{}
+
+QGesture *TwoFingerSwipeRecognizer::create(QObject *target)
+{
+    if (target && target->isWidgetType())
+        qobject_cast<QWidget *>(target)->setAttribute(Qt::WA_AcceptTouchEvents);
+
+    return new TwoFingerSwipe;
+}
+
+QGestureRecognizer::Result TwoFingerSwipeRecognizer::recognize(QGesture *gesture,
+                                                               QObject *,
+                                                               QEvent *event)
+{
+    if (gesture->gestureType() != TwoFingerSwipe::type())
+        return QGestureRecognizer::Ignore;
+
+    TwoFingerSwipe *swipe = static_cast<TwoFingerSwipe *>(gesture);
+    QTouchEvent *touch = static_cast<QTouchEvent *>(event);
+
+    switch (event->type()) {
+    case QEvent::TouchBegin:
+        return swipe->begin(touch);
+
+    case QEvent::TouchUpdate:
+        return swipe->update(touch);
+
+    case QEvent::TouchEnd:
+        return swipe->end(touch);
+
+    default:
+        return QGestureRecognizer::Ignore;
+    }
+}
+
+void TwoFingerSwipeRecognizer::reset(QGesture *gesture)
+{
+    if (gesture->gestureType() == TwoFingerSwipe::type()) {
+        TwoFingerSwipe *swipe = static_cast<TwoFingerSwipe *>(gesture);
+        swipe->reset();
+    }
+    QGestureRecognizer::reset(gesture);
+}
+
+} // End namespace QmlDesigner.

src/plugins/qmldesigner/components/componentcore/gestures.h

@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Design Tooling
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+#pragma once
+
+#include <QGesture>
+#include <QGestureRecognizer>
+#include <QLineF>
+
+QT_FORWARD_DECLARE_CLASS(QTouchEvent)
+
+namespace QmlDesigner {
+
+class TwoFingerSwipe : public QGesture
+{
+    Q_OBJECT
+
+public:
+    TwoFingerSwipe();
+
+    static Qt::GestureType type();
+    static void registerRecognizer();
+
+    QPointF direction() const;
+
+    void reset();
+    QGestureRecognizer::Result begin(QTouchEvent *event);
+    QGestureRecognizer::Result update(QTouchEvent *event);
+    QGestureRecognizer::Result end(QTouchEvent *event);
+
+private:
+    static Qt::GestureType m_type;
+
+    QLineF m_start;
+    QLineF m_current;
+    QLineF m_last;
+};
+
+class TwoFingerSwipeRecognizer : public QGestureRecognizer
+{
+public:
+    TwoFingerSwipeRecognizer();
+
+    QGesture *create(QObject *target) override;
+
+    QGestureRecognizer::Result recognize(QGesture *gesture, QObject *watched, QEvent *event) override;
+
+    void reset(QGesture *gesture) override;
+};
+
+} // namespace QmlDesigner

src/plugins/qmldesigner/components/componentcore/navigation2d.cpp

@@ -23,10 +23,13 @@
 **
 ****************************************************************************/
 #include "navigation2d.h"
+#include "gestures.h"
 
 #include <QGestureEvent>
 #include <QWheelEvent>
 
+#include <cmath>
+
 namespace QmlDesigner {
 
 Navigation2dScrollBar::Navigation2dScrollBar(QWidget *parent)
@@ -53,39 +56,60 @@ Navigation2dFilter::Navigation2dFilter(QWidget *parent, Navigation2dScrollBar *s
     : QObject(parent)
     , m_scrollbar(scrollbar)
 {
-    if (parent)
+    if (parent) {
         parent->grabGesture(Qt::PinchGesture);
+        if (!scrollbar)
+            parent->grabGesture(TwoFingerSwipe::type());
+    }
 }
 
-bool Navigation2dFilter::eventFilter(QObject *, QEvent *event)
+bool Navigation2dFilter::eventFilter(QObject *object, QEvent *event)
 {
     if (event->type() == QEvent::Gesture)
         return gestureEvent(static_cast<QGestureEvent *>(event));
-    else if (event->type() == QEvent::Wheel && m_scrollbar)
+    else if (event->type() == QEvent::Wheel)
         return wheelEvent(static_cast<QWheelEvent *>(event));
 
-    return QObject::event(event);
+    return QObject::eventFilter(object, event);
 }
 
 bool Navigation2dFilter::gestureEvent(QGestureEvent *event)
 {
     if (QPinchGesture *pinch = static_cast<QPinchGesture *>(event->gesture(Qt::PinchGesture))) {
         QPinchGesture::ChangeFlags changeFlags = pinch->changeFlags();
-        if (changeFlags & QPinchGesture::ScaleFactorChanged) {
+        if (changeFlags.testFlag(QPinchGesture::ScaleFactorChanged)) {
             emit zoomChanged(-(1.0 - pinch->scaleFactor()), pinch->startCenterPoint());
             event->accept();
             return true;
         }
+    } else if (TwoFingerSwipe *swipe = static_cast<TwoFingerSwipe *>(
+                   event->gesture(TwoFingerSwipe::type()))) {
+        emit panChanged(swipe->direction());
+        event->accept();
+        return true;
     }
     return false;
 }
 
 bool Navigation2dFilter::wheelEvent(QWheelEvent *event)
 {
-    if (m_scrollbar->postEvent(event))
+    if (m_scrollbar) {
-        event->ignore();
+        if (m_scrollbar->postEvent(event))
-
+            event->ignore();
-    return false;
+    } else if (event->source() == Qt::MouseEventNotSynthesized) {
+        if (event->modifiers().testFlag(Qt::ControlModifier)) {
+            if (QPointF angle = event->angleDelta(); !angle.isNull()) {
+                double delta = std::abs(angle.x()) > std::abs(angle.y()) ? angle.x() : angle.y();
+                if (delta > 0)
+                    emit zoomIn();
+                else
+                    emit zoomOut();
+                event->accept();
+                return true;
+            }
+        }
+    }
+    return true;
 }
 
 } // End namespace QmlDesigner.

src/plugins/qmldesigner/components/componentcore/navigation2d.h

@@ -51,6 +51,10 @@ class Navigation2dFilter : public QObject
 
 signals:
     void zoomChanged(double scale, const QPointF &pos);
+    void panChanged(const QPointF &direction);
+
+    void zoomIn();
+    void zoomOut();
 
 public:
     Navigation2dFilter(QWidget *parent = nullptr, Navigation2dScrollBar *scrollbar = nullptr);

src/plugins/qmldesigner/components/componentcore/zoomaction.cpp

@@ -24,130 +24,135 @@
 ****************************************************************************/
 
 #include "zoomaction.h"
+#include "formeditorwidget.h"
+#include <algorithm>
+#include <iterator>
+#include <utility>
 
-#include <QComboBox>
 #include <QAbstractItemView>
+#include <QComboBox>
+#include <QToolBar>
+
+#include <cmath>
 
 namespace QmlDesigner {
 
-const int defaultZoomIndex = 13;
+// Order matters!
+std::array<double, 27> ZoomAction::m_zooms = {
+    0.01, 0.02, 0.05, 0.0625, 0.1, 0.125, 0.2, 0.25, 0.33, 0.5,  0.66, 0.75, 0.9,
+    1.0, 1.1, 1.25, 1.33, 1.5, 1.66, 1.75, 2.0, 3.0, 4.0, 6.0, 8.0, 10.0, 16.0
+};
+
+bool isValidIndex(int index)
+{
+    if (index >= 0 && index < static_cast<int>(ZoomAction::zoomLevels().size()))
+        return true;
+
+    return false;
+}
 
 ZoomAction::ZoomAction(QObject *parent)
-    :  QWidgetAction(parent),
+    : QWidgetAction(parent)
-    m_zoomLevel(1.0),
+    , m_combo(nullptr)
-    m_currentComboBoxIndex(defaultZoomIndex)
+{}
-{
 
+std::array<double, 27> ZoomAction::zoomLevels()
+{
+    return m_zooms;
 }
 
-float ZoomAction::zoomLevel() const
+int ZoomAction::indexOf(double zoom)
 {
-    return m_zoomLevel;
+    auto finder = [zoom](double val) { return qFuzzyCompare(val, zoom); };
-}
+    if (auto iter = std::find_if(m_zooms.begin(), m_zooms.end(), finder); iter != m_zooms.end())
+        return static_cast<int>(std::distance(m_zooms.begin(), iter));
 
-void ZoomAction::zoomIn()
-{
-    if (m_currentComboBoxIndex < (m_comboBoxModel->rowCount() - 1))
-        emit indexChanged(m_currentComboBoxIndex + 1);
-}
-
-void ZoomAction::zoomOut()
-{
-    if (m_currentComboBoxIndex > 0)
-        emit indexChanged(m_currentComboBoxIndex - 1);
-}
-
-void ZoomAction::resetZoomLevel()
-{
-    m_zoomLevel = 1.0;
-    m_currentComboBoxIndex = defaultZoomIndex;
-    emit reseted();
-}
-
-void ZoomAction::setZoomLevel(float zoomLevel)
-{
-    if (qFuzzyCompare(m_zoomLevel, zoomLevel))
-        return;
-
-    forceZoomLevel(zoomLevel);
-}
-
-void ZoomAction::forceZoomLevel(float zoomLevel)
-{
-    m_zoomLevel = qBound(0.01f, zoomLevel, 16.0f);
-    emit zoomLevelChanged(m_zoomLevel);
-}
-
-//initial m_zoomLevel and m_currentComboBoxIndex
-const QVector<float> s_zoomFactors = {0.01f, 0.02f, 0.05f, 0.0625f, 0.1f, 0.125f, 0.2f, 0.25f,
-                                      0.33f, 0.5f, 0.66f, 0.75f, 0.9f, 1.0f, 1.1f, 1.25f, 1.33f,
-                                      1.5f, 1.66f, 1.75f, 2.0f, 3.0f, 4.0f, 6.0f, 8.0f, 10.0f, 16.0f };
-
-int getZoomIndex(float zoom)
-{
-    for (int i = 0; i < s_zoomFactors.length(); i++) {
-        if (qFuzzyCompare(s_zoomFactors.at(i), zoom))
-            return i;
-    }
     return -1;
 }
 
-float ZoomAction::getClosestZoomLevel(float zoomLevel)
+void ZoomAction::setZoomFactor(double zoom)
 {
-    int i = 0;
+    if (int index = indexOf(zoom); index >= 0) {
-    while (i < s_zoomFactors.size() && s_zoomFactors[i] < zoomLevel)
+        m_combo->setCurrentIndex(index);
-        ++i;
+        m_combo->setToolTip(m_combo->currentText());
+        return;
+    }
+    int rounded = static_cast<int>(std::round(zoom * 100));
+    m_combo->setEditable(true);
+    m_combo->setEditText(QString::number(rounded) + " %");
+    m_combo->setToolTip(m_combo->currentText());
+}
 
-    return s_zoomFactors[qBound(0, i - 1, s_zoomFactors.size() - 1)];
+double ZoomAction::setNextZoomFactor(double zoom)
+{
+    if (zoom >= m_zooms.back())
+        return zoom;
+
+    auto greater = [zoom](double val) { return val > zoom; };
+    if (auto iter = std::find_if(m_zooms.begin(), m_zooms.end(), greater); iter != m_zooms.end()) {
+        auto index = std::distance(m_zooms.begin(), iter);
+        m_combo->setCurrentIndex(static_cast<int>(index));
+        m_combo->setToolTip(m_combo->currentText());
+        return *iter;
+    }
+    return zoom;
+}
+
+double ZoomAction::setPreviousZoomFactor(double zoom)
+{
+    if (zoom <= m_zooms.front())
+        return zoom;
+
+    auto smaller = [zoom](double val) { return val < zoom; };
+    if (auto iter = std::find_if(m_zooms.rbegin(), m_zooms.rend(), smaller); iter != m_zooms.rend()) {
+        auto index = std::distance(iter, m_zooms.rend() - 1);
+        m_combo->setCurrentIndex(static_cast<int>(index));
+        m_combo->setToolTip(m_combo->currentText());
+        return *iter;
+    }
+    return zoom;
+}
+
+bool parentIsFormEditor(QWidget *parent)
+{
+    while (parent) {
+        if (qobject_cast<FormEditorWidget *>(parent))
+            return true;
+        parent = qobject_cast<QWidget *>(parent->parent());
+    }
+    return false;
+}
+
+QComboBox *createZoomComboBox(QWidget *parent)
+{
+    auto *combo = new QComboBox(parent);
+    for (double z : ZoomAction::zoomLevels()) {
+        const QString name = QString::number(z * 100., 'g', 4) + " %";
+        combo->addItem(name, z);
+    }
+    return combo;
 }
 
 QWidget *ZoomAction::createWidget(QWidget *parent)
 {
-    auto comboBox = new QComboBox(parent);
+    if (!m_combo && parentIsFormEditor(parent)) {
+        m_combo = createZoomComboBox(parent);
+        m_combo->setProperty("hideborder", true);
+        m_combo->setCurrentIndex(indexOf(1.0));
+        m_combo->setToolTip(m_combo->currentText());
 
-    /*
+        auto currentChanged = QOverload<int>::of(&QComboBox::currentIndexChanged);
-     * When add zoom levels do not forget to update defaultZoomIndex
+        connect(m_combo, currentChanged, this, &ZoomAction::emitZoomLevelChanged);
-     */
+
-    if (m_comboBoxModel.isNull()) {
+        return m_combo.data();
-        m_comboBoxModel = comboBox->model();
-        for (float z : s_zoomFactors) {
-            const QString name = QString::number(z * 100, 'g', 4) + " %";
-            comboBox->addItem(name, z);
-        }
-    } else {
-        comboBox->setModel(m_comboBoxModel.data());
     }
+    return nullptr;
+}
 
-    comboBox->setCurrentIndex(m_currentComboBoxIndex);
+void ZoomAction::emitZoomLevelChanged(int index)
-    comboBox->setToolTip(comboBox->currentText());
+{
-    connect(this, &ZoomAction::reseted, comboBox, [this, comboBox]() {
+    if (index >= 0 && index < static_cast<int>(m_zooms.size()))
-        blockSignals(true);
+        emit zoomLevelChanged(m_zooms[static_cast<size_t>(index)]);
-        comboBox->setCurrentIndex(m_currentComboBoxIndex);
-        blockSignals(false);
-    });
-    connect(comboBox, QOverload<int>::of(&QComboBox::currentIndexChanged),
-            [this, comboBox](int index) {
-        m_currentComboBoxIndex = index;
-
-        if (index == -1)
-            return;
-
-        const QModelIndex modelIndex(m_comboBoxModel.data()->index(index, 0));
-        setZoomLevel(m_comboBoxModel.data()->data(modelIndex, Qt::UserRole).toFloat());
-        comboBox->setToolTip(modelIndex.data().toString());
-    });
-
-    connect(this, &ZoomAction::indexChanged, comboBox, &QComboBox::setCurrentIndex);
-
-    connect(this, &ZoomAction::zoomLevelChanged, comboBox, [comboBox](double zoom){
-        const int index = getZoomIndex(zoom);
-        if (comboBox->currentIndex() != index)
-            comboBox->setCurrentIndex(index);
-    });
-
-    comboBox->setProperty("hideborder", true);
-    comboBox->setMaximumWidth(qMax(comboBox->view()->sizeHintForColumn(0) / 2, 16));
-    return comboBox;
 }
 
 } // namespace QmlDesigner

src/plugins/qmldesigner/components/componentcore/zoomaction.h

@@ -26,11 +26,13 @@
 
 #include <qmldesignercorelib_global.h>
 
-#include <QWidgetAction>
 #include <QPointer>
+#include <QWidgetAction>
+
+#include <array>
 
 QT_BEGIN_NAMESPACE
-class QAbstractItemModel;
+class QComboBox;
 QT_END_NAMESPACE
 
 namespace QmlDesigner {
@@ -39,30 +41,27 @@ class QMLDESIGNERCORE_EXPORT ZoomAction : public QWidgetAction
 {
     Q_OBJECT
 
+signals:
+    void zoomLevelChanged(double zoom);
+
 public:
     ZoomAction(QObject *parent);
 
-    float zoomLevel() const;
+    static std::array<double, 27> zoomLevels();
+    static int indexOf(double zoom);
 
-    void zoomIn();
+    void setZoomFactor(double zoom);
-    void zoomOut();
+    double setNextZoomFactor(double zoom);
-    void resetZoomLevel();
+    double setPreviousZoomFactor(double zoom);
-    void setZoomLevel(float zoomLevel);
-    void forceZoomLevel(float zoomLevel);
-
-    static float getClosestZoomLevel(float zoomLevel);
 
 protected:
     QWidget *createWidget(QWidget *parent) override;
-signals:
-    void zoomLevelChanged(float zoom);
-    void indexChanged(int);
-    void reseted();
 
 private:
-    QPointer<QAbstractItemModel> m_comboBoxModel;
+    void emitZoomLevelChanged(int index);
-    float m_zoomLevel;
+
-    int m_currentComboBoxIndex;
+    static std::array<double, 27> m_zooms;
+    QPointer<QComboBox> m_combo;
 };
 
 } // namespace QmlDesigner

src/plugins/qmldesigner/components/formeditor/formeditorgraphicsview.cpp

@@ -24,20 +24,24 @@
 ****************************************************************************/
 
 #include "formeditorgraphicsview.h"
+#include "formeditoritem.h"
+#include "formeditorwidget.h"
+#include "navigation2d.h"
 
-#include <QWheelEvent>
+#include <QAction>
-#include <QScrollBar>
-#include <QGraphicsItem>
-#include <QGraphicsWidget>
-#include <QGraphicsProxyWidget>
 #include <QCoreApplication>
+#include <QGraphicsItem>
+#include <QGraphicsProxyWidget>
+#include <QGraphicsWidget>
+#include <QScrollBar>
+#include <QWheelEvent>
 
 #include <QTimer>
 
 namespace QmlDesigner {
 
-FormEditorGraphicsView::FormEditorGraphicsView(QWidget *parent) :
+FormEditorGraphicsView::FormEditorGraphicsView(QWidget *parent)
-    QGraphicsView(parent)
+    : QGraphicsView(parent)
 {
     setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
     setResizeAnchor(QGraphicsView::AnchorViewCenter);
@@ -57,6 +61,39 @@ FormEditorGraphicsView::FormEditorGraphicsView(QWidget *parent) :
     // as mousetracking only works for mouse key it is better to handle it in the
     // eventFilter method so it works also for the space scrolling case as expected
     QCoreApplication::instance()->installEventFilter(this);
+
+    QmlDesigner::Navigation2dFilter *filter = new QmlDesigner::Navigation2dFilter(this);
+    connect(filter, &Navigation2dFilter::zoomIn, this, &FormEditorGraphicsView::zoomIn);
+    connect(filter, &Navigation2dFilter::zoomOut, this, &FormEditorGraphicsView::zoomOut);
+
+    auto panChanged = &Navigation2dFilter::panChanged;
+    connect(filter, panChanged, [this](const QPointF &direction) {
+        QScrollBar *sbx = horizontalScrollBar();
+        QScrollBar *sby = verticalScrollBar();
+
+        // max - min + pageStep = sceneRect.size * scale
+        QPointF min(sbx->minimum(), sby->minimum());
+        QPointF max(sbx->maximum(), sby->maximum());
+        QPointF step(sbx->pageStep(), sby->pageStep());
+
+        QPointF d1 = max - min;
+        QPointF d2 = d1 + step;
+
+        QPoint val = QPointF((direction.x() / d2.x()) * d1.x(), (direction.y() / d2.y()) * d1.y())
+                         .toPoint();
+
+        sbx->setValue(sbx->value() - val.x());
+        sby->setValue(sby->value() - val.y());
+    });
+
+    auto zoomChanged = &Navigation2dFilter::zoomChanged;
+    connect(filter, zoomChanged, [this](double s, const QPointF &/*pos*/) {
+        if (auto trans = transform() * QTransform::fromScale(1.0 + s, 1.0 + s); trans.m11() > 0) {
+            setTransform(trans);
+            emit this->zoomChanged(transform().m11());
+        }
+    });
+    installEventFilter(filter);
 }
 
 bool FormEditorGraphicsView::eventFilter(QObject *watched, QEvent *event)
@@ -67,7 +104,7 @@ bool FormEditorGraphicsView::eventFilter(QObject *watched, QEvent *event)
             stopPanning(event);
         }
         if (event->type() == QEvent::MouseMove) {
-            auto mouseEvent = static_cast<QMouseEvent*>(event);
+            auto mouseEvent = static_cast<QMouseEvent *>(event);
             if (!m_panningStartPosition.isNull()) {
                 horizontalScrollBar()->setValue(horizontalScrollBar()->value() -
                     (mouseEvent->x() - m_panningStartPosition.x()));
@@ -86,7 +123,7 @@ void FormEditorGraphicsView::wheelEvent(QWheelEvent *event)
 {
     if (event->modifiers().testFlag(Qt::ControlModifier))
         event->ignore();
-    else
+    else if (event->source() == Qt::MouseEventNotSynthesized)
         QGraphicsView::wheelEvent(event);
 }
 
@@ -109,7 +146,7 @@ void FormEditorGraphicsView::mouseReleaseEvent(QMouseEvent *event)
         QGraphicsView::mouseReleaseEvent(event);
 }
 
-bool isTextInputItem(QGraphicsItem* item)
+bool isTextInputItem(QGraphicsItem *item)
 {
     if (item && item->isWidget()) {
         auto graphicsWidget = static_cast<QGraphicsWidget *>(item);
@@ -128,7 +165,7 @@ void FormEditorGraphicsView::keyPressEvent(QKeyEvent *event)
 {
     // check for autorepeat to avoid a stoped space panning by leave event to be restarted
     if (!event->isAutoRepeat() && m_isPanning == Panning::NotStarted && event->key() == Qt::Key_Space &&
-            !isTextInputItem(scene()->focusItem())) {
+        !isTextInputItem(scene()->focusItem())) {
         startPanning(event);
         return;
     }
@@ -203,4 +240,15 @@ void FormEditorGraphicsView::drawBackground(QPainter *painter, const QRectF &rec
     painter->restore();
 }
 
+void FormEditorGraphicsView::frame(const QRectF &boundingRect)
+{
+    fitInView(boundingRect, Qt::KeepAspectRatio);
+}
+
+void FormEditorGraphicsView::setZoomFactor(double zoom)
+{
+    resetTransform();
+    scale(zoom, zoom);
+}
+
 } // namespace QmlDesigner

src/plugins/qmldesigner/components/formeditor/formeditorgraphicsview.h

@@ -30,7 +30,13 @@ namespace QmlDesigner {
 
 class FormEditorGraphicsView : public QGraphicsView
 {
-Q_OBJECT
+    Q_OBJECT
+
+signals:
+    void zoomChanged(double zoom);
+    void zoomIn();
+    void zoomOut();
+
 public:
     explicit FormEditorGraphicsView(QWidget *parent = nullptr);
 
@@ -41,6 +47,9 @@ public:
     void activateColoredBackground(const QColor &color);
     void drawBackground(QPainter *painter, const QRectF &rect) override;
 
+    void setZoomFactor(double zoom);
+    void frame(const QRectF &bbox);
+
 protected:
     bool eventFilter(QObject *watched, QEvent *event) override;
     void wheelEvent(QWheelEvent *event) override;
@@ -48,13 +57,13 @@ protected:
     void mouseReleaseEvent(QMouseEvent *event) override;
     void keyPressEvent(QKeyEvent *event) override;
     void keyReleaseEvent(QKeyEvent *event) override;
+
 private:
-    enum Panning{
+    enum Panning { NotStarted, MouseWheelStarted, SpaceKeyStarted };
-        NotStarted, MouseWheelStarted, SpaceKeyStarted
-    };
 
     void startPanning(QEvent *event);
     void stopPanning(QEvent *event);
+
     Panning m_isPanning = Panning::NotStarted;
     QPoint m_panningStartPosition;
     QRectF m_rootItemRect;

src/plugins/qmldesigner/components/formeditor/formeditorview.cpp

@@ -443,53 +443,12 @@ void FormEditorView::documentMessagesChanged(const QList<DocumentMessage> &error
         m_formEditorWidget->hideErrorMessageBox();
 }
 
-void FormEditorView::customNotification(const AbstractView * /*view*/, const QString &identifier, const QList<ModelNode> &nodeList, const QList<QVariant> &/*data*/)
+void FormEditorView::customNotification(const AbstractView * /*view*/, const QString &identifier, const QList<ModelNode> &/*nodeList*/, const QList<QVariant> &/*data*/)
 {
     if (identifier == QLatin1String("puppet crashed"))
         m_dragTool->clearMoveDelay();
     if (identifier == QLatin1String("reset QmlPuppet"))
         temporaryBlockView();
-    if (identifier == QLatin1String("zoom all")) {
-        if (QmlItemNode(rootModelNode()).isFlowView()) {
-            QRectF boundingRect;
-            for (QGraphicsItem *item : scene()->items()) {
-                if (auto formEditorItem = FormEditorItem::fromQGraphicsItem(item)) {
-                    if (!formEditorItem->qmlItemNode().modelNode().isRootNode()
-                        && !formEditorItem->sceneBoundingRect().isNull())
-                        boundingRect = boundingRect.united(formEditorItem->sceneBoundingRect());
-                }
-            }
-            m_formEditorWidget->graphicsView()->fitInView(boundingRect,
-                                                          Qt::KeepAspectRatio);
-        } else {
-            m_formEditorWidget->graphicsView()->fitInView(m_formEditorWidget->rootItemRect(),
-                                                          Qt::KeepAspectRatio);
-        }
-
-        const qreal scaleFactor = m_formEditorWidget->graphicsView()->viewportTransform().m11();
-        float zoomLevel = ZoomAction::getClosestZoomLevel(scaleFactor);
-        m_formEditorWidget->zoomAction()->forceZoomLevel(zoomLevel);
-    }
-    if (identifier == QLatin1String("zoom selection")) {
-        if (nodeList.isEmpty())
-            return;
-
-        QRectF boundingRect;
-        for (const ModelNode &node : nodeList) {
-            if (FormEditorItem *item = scene()->itemForQmlItemNode(node))
-                boundingRect = boundingRect.united(item->sceneBoundingRect());
-        }
-
-        m_formEditorWidget->graphicsView()->fitInView(boundingRect,
-                                                      Qt::KeepAspectRatio);
-        const qreal scaleFactor = m_formEditorWidget->graphicsView()->viewportTransform().m11();
-        float zoomLevel = ZoomAction::getClosestZoomLevel(scaleFactor);
-        m_formEditorWidget->zoomAction()->forceZoomLevel(zoomLevel);
-    }
-    if (identifier == QLatin1String("zoom in"))
-        m_formEditorWidget->zoomAction()->zoomIn();
-    if (identifier == QLatin1String("zoom out"))
-        m_formEditorWidget->zoomAction()->zoomOut();
 }
 
 void FormEditorView::currentStateChanged(const ModelNode & /*node*/)
@@ -791,7 +750,7 @@ void FormEditorView::setupFormEditorWidget()
     if (QmlItemNode::isValidQmlItemNode(rootModelNode()))
         setupFormEditorItemTree(rootModelNode());
 
-    m_formEditorWidget->updateActions();
+    m_formEditorWidget->initialize();
 
     if (!rewriterView()->errors().isEmpty())
         m_formEditorWidget->showErrorMessageBox(rewriterView()->errors());

src/plugins/qmldesigner/components/formeditor/formeditorwidget.cpp

@@ -23,13 +23,13 @@
 **
 ****************************************************************************/
 
-#include "designeractionmanager.h"
 #include "formeditorwidget.h"
-#include "formeditorscene.h"
+#include "designeractionmanager.h"
-#include "qmldesignerplugin.h"
 #include "designersettings.h"
+#include "formeditorscene.h"
 #include "qmldesignerconstants.h"
 #include "qmldesignericons.h"
+#include "qmldesignerplugin.h"
 #include "viewmanager.h"
 #include <model.h>
 #include <theme.h>
@@ -39,16 +39,16 @@
 #include <formeditorscene.h>
 #include <formeditorview.h>
 #include <lineeditaction.h>
-#include <zoomaction.h>
 #include <toolbox.h>
+#include <zoomaction.h>
 
 #include <coreplugin/actionmanager/actionmanager.h>
 #include <coreplugin/actionmanager/command.h>
 #include <coreplugin/icore.h>
 
 #include <utils/fileutils.h>
-#include <utils/utilsicons.h>
 #include <utils/stylehelper.h>
+#include <utils/utilsicons.h>
 
 #include <QActionGroup>
 #include <QFileDialog>
@@ -59,8 +59,8 @@
 
 namespace QmlDesigner {
 
-FormEditorWidget::FormEditorWidget(FormEditorView *view) :
+FormEditorWidget::FormEditorWidget(FormEditorView *view)
-    m_formEditorView(view)
+    : m_formEditorView(view)
 {
     Core::Context context(Constants::C_QMLFORMEDITOR);
     m_context = new Core::IContext(this);
@@ -72,7 +72,7 @@ FormEditorWidget::FormEditorWidget(FormEditorView *view) :
     fillLayout->setSpacing(0);
     setLayout(fillLayout);
 
-    QList<QAction*> upperActions;
+    QList<QAction *> upperActions;
 
     m_toolActionGroup = new QActionGroup(this);
 
@@ -128,7 +128,7 @@ FormEditorWidget::FormEditorWidget(FormEditorView *view) :
     addAction(m_rootWidthAction.data());
     upperActions.append(m_rootWidthAction.data());
 
-    m_rootHeightAction =  new LineEditAction(tr("Override Height"), this);
+    m_rootHeightAction = new LineEditAction(tr("Override Height"), this);
     m_rootHeightAction->setToolTip(tr("Override height of root item."));
     connect(m_rootHeightAction.data(), &LineEditAction::textChanged,
             this, &FormEditorWidget::changeRootItemHeight);
@@ -150,9 +150,8 @@ FormEditorWidget::FormEditorWidget(FormEditorView *view) :
     const QString fontName = "qtds_propertyIconFont.ttf";
     const QColor textColorNormal(Theme::getColor(Theme::MenuItemTextColorNormal));
     const QColor textColorDisabled(Theme::getColor(Theme::MenuBarItemTextColorDisabled));
-    const QIcon zoomAllIcon = Utils::StyleHelper::getIconFromIconFont(fontName,
+    const QIcon zoomAllIcon = Utils::StyleHelper::getIconFromIconFont(
-                                                                      Theme::getIconUnicode(Theme::Icon::zoomAll),
+        fontName, Theme::getIconUnicode(Theme::Icon::zoomAll), 28, 28, textColorNormal);
-                                                                      28, 28, textColorNormal);
 
     const QString zoomSelectionUnicode = Theme::getIconUnicode(Theme::Icon::zoomSelection);
     const auto zoomSelectionNormal = Utils::StyleHelper::IconFontHelper(zoomSelectionUnicode,
@@ -167,68 +166,101 @@ FormEditorWidget::FormEditorWidget(FormEditorView *view) :
     const QIcon zoomSelectionIcon = Utils::StyleHelper::getIconFromIconFont(fontName,
                                                                             {zoomSelectionNormal,
                                                                              zoomSelectionDisabeld});
-    const QIcon zoomInIcon = Utils::StyleHelper::getIconFromIconFont(fontName,
+    const QIcon zoomInIcon = Utils::StyleHelper::getIconFromIconFont(
-                                                                     Theme::getIconUnicode(Theme::Icon::zoomIn),
+        fontName, Theme::getIconUnicode(Theme::Icon::zoomIn), 28, 28, textColorNormal);
-                                                                     28, 28, textColorNormal);
+    const QIcon zoomOutIcon = Utils::StyleHelper::getIconFromIconFont(
-    const QIcon zoomOutIcon = Utils::StyleHelper::getIconFromIconFont(fontName,
+        fontName, Theme::getIconUnicode(Theme::Icon::zoomOut), 28, 28, textColorNormal);
-                                                                      Theme::getIconUnicode(Theme::Icon::zoomOut),
+
-                                                                      28, 28, textColorNormal);
+    auto writeZoomLevel = [this]() {
+        double level = m_graphicsView->transform().m11();
+        if (level == 1.0) {
+            if (m_formEditorView->rootModelNode().hasAuxiliaryData("formeditorZoom"))
+                m_formEditorView->rootModelNode().setAuxiliaryData("formeditorZoom", {});
+        } else {
+            m_formEditorView->rootModelNode().setAuxiliaryData("formeditorZoom", level);
+        }
+    };
+
+    auto setZoomLevel = [this, writeZoomLevel](double level) {
+        if (m_graphicsView) {
+            m_graphicsView->setZoomFactor(level);
+            writeZoomLevel();
+        }
+    };
+
+    auto zoomIn = [this, writeZoomLevel]() {
+        if (m_graphicsView) {
+            double zoom = m_graphicsView->transform().m11();
+            zoom = m_zoomAction->setNextZoomFactor(zoom);
+            m_graphicsView->setZoomFactor(zoom);
+            writeZoomLevel();
+        }
+    };
+
+    auto zoomOut = [this, writeZoomLevel]() {
+        if (m_graphicsView) {
+            double zoom = m_graphicsView->transform().m11();
+            zoom = m_zoomAction->setPreviousZoomFactor(zoom);
+            m_graphicsView->setZoomFactor(zoom);
+            writeZoomLevel();
+        }
+    };
+
+    auto frameAll = [this, zoomOut]() {
+        if (m_graphicsView) {
+            m_graphicsView->frame(m_graphicsView->rootItemRect());
+            zoomOut();
+        }
+    };
+
+    auto frameSelection = [this, zoomOut]() {
+        if (m_graphicsView) {
+            QRectF boundingRect;
+            const QList<ModelNode> nodeList = m_formEditorView->selectedModelNodes();
+            for (const ModelNode &node : nodeList) {
+                if (FormEditorItem *item = m_formEditorView->scene()->itemForQmlItemNode(node))
+                    boundingRect |= item->sceneBoundingRect();
+            }
+            m_graphicsView->frame(boundingRect);
+            zoomOut();
+        }
+    };
 
     m_zoomInAction = new QAction(zoomInIcon, tr("Zoom in"), this);
     m_zoomInAction->setShortcut(QKeySequence(Qt::CTRL | Qt::ALT | Qt::Key_Plus));
-    connect(m_zoomInAction.data(), &QAction::triggered, this, [this] {
-        if (!m_formEditorView)
-            return;
-
-        m_formEditorView->emitCustomNotification(QStringLiteral("zoom in"));
-    });
     addAction(m_zoomInAction.data());
     upperActions.append(m_zoomInAction.data());
     m_toolBox->addRightSideAction(m_zoomInAction.data());
+    connect(m_zoomInAction.data(), &QAction::triggered, zoomIn);
 
     m_zoomOutAction = new QAction(zoomOutIcon, tr("Zoom out"), this);
     m_zoomOutAction->setShortcut(QKeySequence(Qt::CTRL | Qt::ALT | Qt::Key_Minus));
-    connect(m_zoomOutAction.data(), &QAction::triggered, this, [this] {
-        if (!m_formEditorView)
-            return;
-
-        m_formEditorView->emitCustomNotification(QStringLiteral("zoom out"));
-    });
     addAction(m_zoomOutAction.data());
     upperActions.append(m_zoomOutAction.data());
     m_toolBox->addRightSideAction(m_zoomOutAction.data());
+    connect(m_zoomOutAction.data(), &QAction::triggered, zoomOut);
 
     m_zoomAction = new ZoomAction(m_toolActionGroup.data());
-    connect(m_zoomAction.data(), &ZoomAction::zoomLevelChanged,
-            this, &FormEditorWidget::setZoomLevel);
     addAction(m_zoomAction.data());
     upperActions.append(m_zoomAction.data());
     m_toolBox->addRightSideAction(m_zoomAction.data());
+    connect(m_zoomAction.data(), &ZoomAction::zoomLevelChanged, setZoomLevel);
 
     m_zoomAllAction = new QAction(zoomAllIcon, tr("Zoom screen to fit all content"), this);
     m_zoomAllAction->setShortcut(QKeySequence(Qt::CTRL | Qt::ALT | Qt::Key_0));
-    connect(m_zoomAllAction.data(), &QAction::triggered, this, [this] {
-        if (!m_formEditorView)
-            return;
-
-        m_formEditorView->emitCustomNotification(QStringLiteral("zoom all"));
-    });
     addAction(m_zoomAllAction.data());
     upperActions.append(m_zoomAllAction.data());
     m_toolBox->addRightSideAction(m_zoomAllAction.data());
+    connect(m_zoomAllAction.data(), &QAction::triggered, frameAll);
 
-    m_zoomSelectionAction = new QAction(zoomSelectionIcon, tr("Zoom screen to fit current selection"), this);
+    m_zoomSelectionAction = new QAction(zoomSelectionIcon,
+                                        tr("Zoom screen to fit current selection"),
+                                        this);
     m_zoomSelectionAction->setShortcut(QKeySequence(Qt::CTRL | Qt::ALT | Qt::Key_I));
-    connect(m_zoomSelectionAction.data(), &QAction::triggered, this, [this] {
-        if (!m_formEditorView)
-            return;
-
-        m_formEditorView->emitCustomNotification(QStringLiteral("zoom selection"),
-                                                 m_formEditorView->selectedModelNodes());
-    });
     addAction(m_zoomSelectionAction.data());
     upperActions.append(m_zoomSelectionAction.data());
     m_toolBox->addRightSideAction(m_zoomSelectionAction.data());
+    connect(m_zoomSelectionAction.data(), &QAction::triggered, frameSelection);
 
     m_resetAction = new QAction(Utils::Icons::RESET_TOOLBAR.icon(), tr("Reset View"), this);
     registerActionAsCommand(m_resetAction, Constants::FORMEDITOR_REFRESH, QKeySequence(Qt::Key_R));
@@ -238,6 +270,10 @@ FormEditorWidget::FormEditorWidget(FormEditorView *view) :
     m_toolBox->addRightSideAction(m_resetAction.data());
 
     m_graphicsView = new FormEditorGraphicsView(this);
+    auto applyZoom = [this](double zoom) { zoomAction()->setZoomFactor(zoom); };
+    connect(m_graphicsView, &FormEditorGraphicsView::zoomChanged, applyZoom);
+    connect(m_graphicsView, &FormEditorGraphicsView::zoomIn, zoomIn);
+    connect(m_graphicsView, &FormEditorGraphicsView::zoomOut, zoomOut);
 
     fillLayout->addWidget(m_graphicsView.data());
 
@@ -293,50 +329,46 @@ void FormEditorWidget::registerActionAsCommand(QAction *action, Utils::Id id, co
     command->augmentActionWithShortcutToolTip(action);
 }
 
-void FormEditorWidget::wheelEvent(QWheelEvent *event)
+void FormEditorWidget::initialize()
 {
-    if (event->modifiers().testFlag(Qt::ControlModifier)) {
+    double defaultZoom = 1.0;
-        if (event->angleDelta().y() > 0)
+    if (m_formEditorView->model() && m_formEditorView->rootModelNode().isValid()) {
-            zoomAction()->zoomIn();
+        if (m_formEditorView->rootModelNode().hasAuxiliaryData("formeditorZoom"))
-        else
+            defaultZoom = m_formEditorView->rootModelNode().auxiliaryData("formeditorZoom").toDouble();
-            zoomAction()->zoomOut();
-
-        event->accept();
-    } else {
-        QWidget::wheelEvent(event);
     }
-
+    m_graphicsView->setZoomFactor(defaultZoom);
+    m_zoomAction->setZoomFactor(defaultZoom);
+    updateActions();
 }
 
 void FormEditorWidget::updateActions()
 {
     if (m_formEditorView->model() && m_formEditorView->rootModelNode().isValid()) {
-        if (m_formEditorView->rootModelNode().hasAuxiliaryData("width") && m_formEditorView->rootModelNode().auxiliaryData("width").isValid())
+        if (m_formEditorView->rootModelNode().hasAuxiliaryData("width")
-            m_rootWidthAction->setLineEditText(m_formEditorView->rootModelNode().auxiliaryData("width").toString());
+            && m_formEditorView->rootModelNode().auxiliaryData("width").isValid())
+            m_rootWidthAction->setLineEditText(
+                m_formEditorView->rootModelNode().auxiliaryData("width").toString());
         else
             m_rootWidthAction->clearLineEditText();
-        if (m_formEditorView->rootModelNode().hasAuxiliaryData("height") && m_formEditorView->rootModelNode().auxiliaryData("height").isValid())
+        if (m_formEditorView->rootModelNode().hasAuxiliaryData("height")
-            m_rootHeightAction->setLineEditText(m_formEditorView->rootModelNode().auxiliaryData("height").toString());
+            && m_formEditorView->rootModelNode().auxiliaryData("height").isValid())
+            m_rootHeightAction->setLineEditText(
+                m_formEditorView->rootModelNode().auxiliaryData("height").toString());
         else
             m_rootHeightAction->clearLineEditText();
 
         if (m_formEditorView->rootModelNode().hasAuxiliaryData("formeditorColor"))
-            m_backgroundAction->setColor(m_formEditorView->rootModelNode().auxiliaryData("formeditorColor").value<QColor>());
+            m_backgroundAction->setColor(
+                m_formEditorView->rootModelNode().auxiliaryData("formeditorColor").value<QColor>());
         else
             m_backgroundAction->setColor(Qt::transparent);
 
-        if (m_formEditorView->rootModelNode().hasAuxiliaryData("formeditorZoom"))
-            m_zoomAction->setZoomLevel(m_formEditorView->rootModelNode().auxiliaryData("formeditorZoom").toDouble());
-        else
-            m_zoomAction->setZoomLevel(1.0);
-
     } else {
         m_rootWidthAction->clearLineEditText();
         m_rootHeightAction->clearLineEditText();
     }
 }
 
-
 void FormEditorWidget::resetView()
 {
     setRootItemRect(QRectF());
@@ -371,8 +403,8 @@ void FormEditorWidget::hideErrorMessageBox()
 
 void FormEditorWidget::showWarningMessageBox(const QList<DocumentMessage> &warnings)
 {
-      if (!errorWidget()->warningsEnabled())
+    if (!errorWidget()->warningsEnabled())
-          return;
+        return;
 
     errorWidget()->setWarnings(warnings);
     errorWidget()->setVisible(true);
@@ -408,20 +440,6 @@ QAction *FormEditorWidget::snappingAndAnchoringAction() const
     return m_snappingAndAnchoringAction.data();
 }
 
-void FormEditorWidget::setZoomLevel(double zoomLevel)
-{
-    m_graphicsView->resetTransform();
-
-    m_graphicsView->scale(zoomLevel, zoomLevel);
-
-    if (zoomLevel == 1.0) {
-        if (m_formEditorView->rootModelNode().hasAuxiliaryData("formeditorZoom"))
-            m_formEditorView->rootModelNode().setAuxiliaryData("formeditorZoom", {});
-    } else {
-        m_formEditorView->rootModelNode().setAuxiliaryData("formeditorZoom", zoomLevel);
-    }
-}
-
 void FormEditorWidget::setScene(FormEditorScene *scene)
 {
     m_graphicsView->setScene(scene);
@@ -434,7 +452,7 @@ QActionGroup *FormEditorWidget::toolActionGroup() const
 
 ToolBox *FormEditorWidget::toolBox() const
 {
-     return m_toolBox.data();
+    return m_toolBox.data();
 }
 
 double FormEditorWidget::spacing() const
@@ -510,10 +528,11 @@ DocumentWarningWidget *FormEditorWidget::errorWidget()
 {
     if (m_documentErrorWidget.isNull()) {
         m_documentErrorWidget = new DocumentWarningWidget(this);
-        connect(m_documentErrorWidget.data(), &DocumentWarningWidget::gotoCodeClicked, [=]
+        connect(m_documentErrorWidget.data(),
-            (const QString &, int codeLine, int codeColumn) {
+                &DocumentWarningWidget::gotoCodeClicked,
-            m_formEditorView->gotoError(codeLine, codeColumn);
+                [=](const QString &, int codeLine, int codeColumn) {
-        });
+                    m_formEditorView->gotoError(codeLine, codeColumn);
+                });
     }
     return m_documentErrorWidget;
 }

src/plugins/qmldesigner/components/formeditor/formeditorwidget.h

@@ -28,8 +28,8 @@
 
 #include <coreplugin/icontext.h>
 
-#include <QWidget>
 #include <QPointer>
+#include <QWidget>
 
 QT_BEGIN_NAMESPACE
 class QActionGroup;
@@ -70,6 +70,7 @@ public:
     void setRootItemRect(const QRectF &rect);
     QRectF rootItemRect() const;
 
+    void initialize();
     void updateActions();
 
     void resetView();
@@ -88,7 +89,6 @@ public:
     FormEditorGraphicsView *graphicsView() const;
 
 protected:
-    void wheelEvent(QWheelEvent *event) override;
     QActionGroup *toolActionGroup() const;
     DocumentWarningWidget *errorWidget();
     void hideEvent(QHideEvent *event) override;
@@ -96,7 +96,6 @@ protected:
 
 private:
     void changeTransformTool(bool checked);
-    void setZoomLevel(double zoomLevel);
     void changeRootItemWidth(const QString &widthText);
     void changeRootItemHeight(const QString &heightText);
     void changeBackgound(const QColor &color);

src/plugins/qmldesigner/qmldesignerplugin.cpp

@@ -32,6 +32,7 @@
 #include "openuiqmlfiledialog.h"
 #include "generateresource.h"
 #include "nodeinstanceview.h"
+#include "gestures.h"
 
 #include <metainfo.h>
 #include <connectionview.h>
@@ -221,6 +222,8 @@ bool QmlDesignerPlugin::initialize(const QStringList & /*arguments*/, QString *e
     if (QFontDatabase::addApplicationFont(fontPath) < 0)
         qCWarning(qmldesignerLog) << "Could not add font " << fontPath << "to font database";
 
+    TwoFingerSwipe::registerRecognizer();
+
     return true;
 }
 

src/plugins/qmldesigner/qmldesignerplugin.qbs

@@ -452,6 +452,8 @@ Project {
                 "componentcore/designeractionmanagerview.h",
                 "componentcore/findimplementation.cpp",
                 "componentcore/findimplementation.h",
+                "componentcore/gestures.cpp",
+                "componentcore/gestures.h",
                 "componentcore/layoutingridlayout.cpp",
                 "componentcore/layoutingridlayout.h",
                 "componentcore/theme.cpp",