diff --git a/src/plugins/designer/designercontext.cpp b/src/plugins/designer/designercontext.cpp
index 0ea7808bc06..001c40cab79 100644
--- a/src/plugins/designer/designercontext.cpp
+++ b/src/plugins/designer/designercontext.cpp
@@ -51,7 +51,7 @@ DesignerContext::DesignerContext(const Core::Context &context,
 
 QString DesignerContext::contextHelpId() const
 {
-    const QDesignerFormEditorInterface *core = FormEditorW::instance()->designerEditor();
+    const QDesignerFormEditorInterface *core = FormEditorW::designerEditor();
     return core->integration()->contextHelpId();
 }
 
diff --git a/src/plugins/designer/editorwidget.cpp b/src/plugins/designer/editorwidget.cpp
index 41506b18be5..c2dfa92bab5 100644
--- a/src/plugins/designer/editorwidget.cpp
+++ b/src/plugins/designer/editorwidget.cpp
@@ -99,9 +99,12 @@ QDockWidget* const* EditorWidget::designerDockWidgets() const
     return m_designerDockWidgets;
 }
 
-void EditorWidget::add(const EditorData &d)
+void EditorWidget::add(SharedTools::WidgetHost *widgetHost, FormWindowEditor *formWindowEditor)
 {
-    m_stack->add(d);
+    EditorData data;
+    data.formWindowEditor = formWindowEditor;
+    data.widgetHost = widgetHost;
+    m_stack->add(data);
 }
 
 void EditorWidget::removeFormWindowEditor(Core::IEditor *xmlEditor)
diff --git a/src/plugins/designer/editorwidget.h b/src/plugins/designer/editorwidget.h
index bb8d10167df..7bae38c2b73 100644
--- a/src/plugins/designer/editorwidget.h
+++ b/src/plugins/designer/editorwidget.h
@@ -42,6 +42,9 @@ namespace SharedTools { class WidgetHost; }
 namespace Core { class IEditor; }
 
 namespace Designer {
+
+class FormWindowEditor;
+
 namespace Internal {
 
 class EditorData;
@@ -59,7 +62,7 @@ public:
     QDockWidget* const* designerDockWidgets() const;
 
     // Form editor stack API
-    void add(const EditorData &d);
+    void add(SharedTools::WidgetHost *widgetHost, FormWindowEditor *formWindowEditor);
     void removeFormWindowEditor(Core::IEditor *xmlEditor);
     bool setVisibleEditor(Core::IEditor *xmlEditor);
     SharedTools::WidgetHost *formWindowEditorForXmlEditor(const Core::IEditor *xmlEditor) const;
diff --git a/src/plugins/designer/formeditorfactory.cpp b/src/plugins/designer/formeditorfactory.cpp
index 1a8435dafb9..763b543dff7 100644
--- a/src/plugins/designer/formeditorfactory.cpp
+++ b/src/plugins/designer/formeditorfactory.cpp
@@ -30,13 +30,9 @@
 #include "formeditorfactory.h"
 #include "formeditorw.h"
 #include "formwindoweditor.h"
-#include "editordata.h"
 
 #include <coreplugin/coreconstants.h>
-#include <coreplugin/icore.h>
-#include <coreplugin/infobar.h>
 #include <coreplugin/fileiconprovider.h>
-#include <coreplugin/modemanager.h>
 
 #include <QCoreApplication>
 #include <QDebug>
@@ -48,25 +44,17 @@ namespace Designer {
 namespace Internal {
 
 FormEditorFactory::FormEditorFactory()
-  : Core::IEditorFactory(Core::ICore::instance())
 {
     setId(K_DESIGNER_XML_EDITOR_ID);
     setDisplayName(qApp->translate("Designer", C_DESIGNER_XML_DISPLAY_NAME));
     addMimeType(FORM_MIMETYPE);
 
-    Core::FileIconProvider::registerIconOverlayForSuffix(":/formeditor/images/qt_ui.png", "ui");
+    FileIconProvider::registerIconOverlayForSuffix(":/formeditor/images/qt_ui.png", "ui");
 }
 
-Core::IEditor *FormEditorFactory::createEditor()
+IEditor *FormEditorFactory::createEditor()
 {
-    const EditorData data = FormEditorW::instance()->createEditor();
-    if (data.formWindowEditor) {
-        Core::InfoBarEntry info(Core::Id(Constants::INFO_READ_ONLY),
-                                tr("This file can only be edited in <b>Design</b> mode."));
-        info.setCustomButtonInfo(tr("Switch Mode"), []() { ModeManager::activateMode(Core::Constants::MODE_DESIGN); });
-        data.formWindowEditor->document()->infoBar()->addInfo(info);
-    }
-    return data.formWindowEditor;
+    return FormEditorW::createEditor();
 }
 
 } // namespace Internal
diff --git a/src/plugins/designer/formeditorw.cpp b/src/plugins/designer/formeditorw.cpp
index de7c4b589a9..45199b0527c 100644
--- a/src/plugins/designer/formeditorw.cpp
+++ b/src/plugins/designer/formeditorw.cpp
@@ -36,16 +36,17 @@
 #include "editordata.h"
 #include "qtcreatorintegration.h"
 #include "designercontext.h"
-#include "resourcehandler.h"
 #include <widgethost.h>
 
 #include <coreplugin/editortoolbar.h>
 #include <coreplugin/designmode.h>
 #include <coreplugin/coreconstants.h>
 #include <coreplugin/icore.h>
+#include <coreplugin/infobar.h>
 #include <coreplugin/helpmanager.h>
 #include <coreplugin/actionmanager/actionmanager.h>
 #include <coreplugin/actionmanager/actioncontainer.h>
+#include <coreplugin/modemanager.h>
 #include <coreplugin/minisplitter.h>
 #include <coreplugin/mimedatabase.h>
 #include <coreplugin/outputpane.h>
@@ -129,33 +130,116 @@ public:
     FormWindowEditorFactory()
     {
         setId(Designer::Constants::K_DESIGNER_XML_EDITOR_ID);
-        setDocumentCreator([this]() { return new FormWindowFile(m_form); });
         setEditorCreator([]() { return new FormWindowEditor; });
         setEditorWidgetCreator([]() { return new Internal::DesignerXmlEditorWidget; });
         setDuplicatedSupported(false);
     }
 
-    QDesignerFormWindowInterface *m_form;
+    FormWindowEditor *create(QDesignerFormWindowInterface *form)
+    {
+        setDocumentCreator([form]() { return new FormWindowFile(form); });
+        return qobject_cast<FormWindowEditor *>(createEditor());
+    }
 };
 
-static FormWindowEditorFactory *m_xmlEditorFactory = 0;
-
 // --------- FormEditorW
 
-static FormEditorW *m_self = 0;
+class FormEditorData
+{
+public:
+    Q_DECLARE_TR_FUNCTIONS(FormEditorW)
 
-FormEditorW::FormEditorW() :
+public:
+    FormEditorData();
+    ~FormEditorData();
+
+    void activateEditMode(int id);
+    void toolChanged(int);
+    void print();
+    void setPreviewMenuEnabled(bool e);
+    void updateShortcut(QObject *command);
+
+    void fullInit();
+
+    void saveSettings(QSettings *s);
+
+    void initDesignerSubWindows();
+
+    void setupActions();
+    void setupViewActions();
+    void addDockViewAction(Core::ActionContainer *viewMenu,
+                           int index,
+                           const Core::Context &context,
+                           const QString &title, Core::Id id);
+
+    Core::ActionContainer *createPreviewStyleMenu(QActionGroup *actionGroup);
+
+    void critical(const QString &errorMessage);
+    void bindShortcut(Core::Command *command, QAction *action);
+    QAction *createEditModeAction(QActionGroup *ag,
+                                  const Core::Context &context,
+                                  Core::ActionContainer *medit,
+                                  const QString &actionName,
+                                  Core::Id id,
+                                  int toolNumber,
+                                  const QString &iconName = QString(),
+                                  const QString &keySequence = QString());
+    Core::Command *addToolAction(QAction *a,
+                                 const Core::Context &context, Core::Id id,
+                                 Core::ActionContainer *c1, const QString &keySequence = QString(),
+                                 Core::Id groupId = Core::Id());
+    QToolBar *createEditorToolBar() const;
+    Core::IEditor *createEditor();
+
+public:
+    QDesignerFormEditorInterface *m_formeditor;
+    QDesignerIntegrationInterface *m_integration;
+    QDesignerFormWindowManagerInterface *m_fwm;
+    FormEditorW::InitializationStage m_initStage;
+
+    QWidget *m_designerSubWindows[Designer::Constants::DesignerSubWindowCount];
+
+    QAction *m_lockAction;
+    QAction *m_resetLayoutAction;
+
+    QList<Core::IOptionsPage *> m_settingsPages;
+    QActionGroup *m_actionGroupEditMode;
+    QAction *m_actionPrint;
+    QAction *m_actionPreview;
+    QActionGroup *m_actionGroupPreviewInStyle;
+    QMenu *m_previewInStyleMenu;
+    QAction *m_actionAboutPlugins;
+    QSignalMapper m_shortcutMapper;
+
+    DesignerContext *m_context;
+    Core::Context m_contexts;
+
+    QList<Core::Id> m_toolActionIds;
+    QWidget *m_modeWidget;
+    EditorWidget *m_editorWidget;
+    Core::DesignMode *m_designMode;
+
+    QWidget *m_editorToolBar;
+    Core::EditorToolBar *m_toolBar;
+
+    QMap<Core::Command *, QAction *> m_commandToDesignerAction;
+    FormWindowEditorFactory *m_xmlEditorFactory = 0;
+};
+
+static FormEditorData *d = 0;
+static FormEditorW *m_instance = 0;
+
+FormEditorData::FormEditorData() :
     m_formeditor(QDesignerComponents::createFormEditor(0)),
     m_integration(0),
     m_fwm(0),
-    m_initStage(RegisterPlugins),
+    m_initStage(FormEditorW::RegisterPlugins),
     m_actionGroupEditMode(0),
     m_actionPrint(0),
     m_actionPreview(0),
     m_actionGroupPreviewInStyle(0),
     m_previewInStyleMenu(0),
     m_actionAboutPlugins(0),
-    m_shortcutMapper(new QSignalMapper(this)),
     m_context(0),
     m_modeWidget(0),
     m_editorWidget(0),
@@ -165,8 +249,8 @@ FormEditorW::FormEditorW() :
 {
     if (Designer::Constants::Internal::debug)
         qDebug() << Q_FUNC_INFO;
-    QTC_ASSERT(!m_self, return);
-    m_self = this;
+    QTC_ASSERT(!d, return);
+    d = this;
 
     qFill(m_designerSubWindows, m_designerSubWindows + Designer::Constants::DesignerSubWindowCount,
           static_cast<QWidget *>(0));
@@ -186,19 +270,32 @@ FormEditorW::FormEditorW() :
         m_settingsPages.append(settingsPage);
     }
 
-    connect(EditorManager::instance(), SIGNAL(currentEditorChanged(Core::IEditor*)),
-            this, SLOT(currentEditorChanged(Core::IEditor*)));
-    connect(m_shortcutMapper, SIGNAL(mapped(QObject*)),
-            this, SLOT(updateShortcut(QObject*)));
+    QObject::connect(EditorManager::instance(), &EditorManager::currentEditorChanged, [this](IEditor *editor) {
+        if (Designer::Constants::Internal::debug)
+            qDebug() << Q_FUNC_INFO << editor << " of " << m_fwm->formWindowCount();
+
+        if (editor && editor->document()->id() == Constants::K_DESIGNER_XML_EDITOR_ID) {
+            FormWindowEditor *xmlEditor = qobject_cast<FormWindowEditor *>(editor);
+            QTC_ASSERT(xmlEditor, return);
+            FormEditorW::ensureInitStage(FormEditorW::FullyInitialized);
+            SharedTools::WidgetHost *fw = m_editorWidget->formWindowEditorForXmlEditor(xmlEditor);
+            QTC_ASSERT(fw, return);
+            m_editorWidget->setVisibleEditor(xmlEditor);
+            m_fwm->setActiveFormWindow(fw->formWindow());
+        }
+    });
+
+    QObject::connect(&m_shortcutMapper, static_cast<void(QSignalMapper::*)(QObject *)>(&QSignalMapper::mapped),
+        [this](QObject *ob) { updateShortcut(ob); });
 
     m_xmlEditorFactory = new FormWindowEditorFactory;
 }
 
-FormEditorW::~FormEditorW()
+FormEditorData::~FormEditorData()
 {
     if (m_context)
         ICore::removeContextObject(m_context);
-    if (m_initStage == FullyInitialized) {
+    if (m_initStage == FormEditorW::FullyInitialized) {
         QSettings *s = ICore::settings();
         s->beginGroup(QLatin1String(settingsGroupC));
         m_editorWidget->saveSettings(s);
@@ -215,11 +312,11 @@ FormEditorW::~FormEditorW()
     delete m_integration;
 
     delete m_xmlEditorFactory ;
-    m_self = 0;
+    d = 0;
 }
 
 // Add an actioon to toggle the view state of a dock window
-void FormEditorW::addDockViewAction(ActionContainer *viewMenu,
+void FormEditorData::addDockViewAction(ActionContainer *viewMenu,
                                     int index, const Context &context,
                                     const QString &title, Id id)
 {
@@ -231,7 +328,7 @@ void FormEditorW::addDockViewAction(ActionContainer *viewMenu,
     }
 }
 
-void FormEditorW::setupViewActions()
+void FormEditorData::setupViewActions()
 {
     // Populate "View" menu of form editor menu
     ActionContainer *viewMenu = ActionManager::actionContainer(Core::Constants::M_WINDOW_VIEWS);
@@ -256,27 +353,30 @@ void FormEditorW::setupViewActions()
     cmd->setAttribute(Command::CA_Hide);
 
     cmd = addToolAction(m_editorWidget->resetLayoutAction(), m_contexts, "FormEditor.ResetToDefaultLayout", viewMenu);
-    connect(m_editorWidget, SIGNAL(resetLayout()), m_editorWidget, SLOT(resetToDefaultLayout()));
+
+    QObject::connect(m_editorWidget, &EditorWidget::resetLayout,
+                     m_editorWidget, &EditorWidget::resetToDefaultLayout);
+
     cmd->setAttribute(Command::CA_Hide);
 }
 
-void FormEditorW::fullInit()
+void FormEditorData::fullInit()
 {
-    QTC_ASSERT(m_initStage == RegisterPlugins, return);
+    QTC_ASSERT(m_initStage == FormEditorW::RegisterPlugins, return);
     QTime *initTime = 0;
     if (Designer::Constants::Internal::debug) {
         initTime = new QTime;
         initTime->start();
     }
 
-    QDesignerComponents::createTaskMenu(m_formeditor, parent());
-    QDesignerComponents::initializePlugins(designerEditor());
+    QDesignerComponents::createTaskMenu(m_formeditor, m_instance);
+    QDesignerComponents::initializePlugins(m_formeditor);
     QDesignerComponents::initializeResources();
     initDesignerSubWindows();
-    m_integration = new QtCreatorIntegration(m_formeditor, this);
+    m_integration = new QtCreatorIntegration(m_formeditor, m_instance);
     m_formeditor->setIntegration(m_integration);
     // Connect Qt Designer help request to HelpManager.
-    connect(m_integration, SIGNAL(creatorHelpRequested(QUrl)),
+    QObject::connect(m_integration, SIGNAL(creatorHelpRequested(QUrl)),
         HelpManager::instance(), SLOT(handleHelpRequest(QUrl)));
 
     /**
@@ -299,10 +399,13 @@ void FormEditorW::fullInit()
         delete initTime;
     }
 
-    connect(EditorManager::instance(), SIGNAL(editorsClosed(QList<Core::IEditor*>)),
-            SLOT(closeFormEditorsForXmlEditors(QList<Core::IEditor*>)));
+    QObject::connect(EditorManager::instance(), &EditorManager::editorsClosed, [this] (QList<IEditor*> editors) {
+        foreach (IEditor *editor, editors)
+            m_editorWidget->removeFormWindowEditor(editor);
+    });
+
     // Nest toolbar and editor widget
-    m_editorWidget = new EditorWidget(this);
+    m_editorWidget = new EditorWidget(m_instance);
     QSettings *settings = ICore::settings();
     settings->beginGroup(QLatin1String(settingsGroupC));
     m_editorWidget->restoreSettings(settings);
@@ -333,17 +436,17 @@ void FormEditorW::fullInit()
 
     Context designerContexts = m_contexts;
     designerContexts.add(Core::Constants::C_EDITORMANAGER);
-    m_context = new DesignerContext(designerContexts, m_modeWidget, this);
+    m_context = new DesignerContext(designerContexts, m_modeWidget, m_instance);
     ICore::addContextObject(m_context);
 
     m_designMode->registerDesignWidget(m_modeWidget, QStringList(QLatin1String(FORM_MIMETYPE)), m_contexts);
 
     setupViewActions();
 
-    m_initStage = FullyInitialized;
+    m_initStage = FormEditorW::FullyInitialized;
 }
 
-void FormEditorW::initDesignerSubWindows()
+void FormEditorData::initDesignerSubWindows()
 {
     qFill(m_designerSubWindows, m_designerSubWindows + Designer::Constants::DesignerSubWindowCount, static_cast<QWidget*>(0));
 
@@ -375,38 +478,44 @@ void FormEditorW::initDesignerSubWindows()
     ae->setObjectName(QLatin1String("ActionEditor"));
     m_formeditor->setActionEditor(ae);
     m_designerSubWindows[ActionEditorSubWindow] = ae;
+    m_initStage = FormEditorW::SubwindowsInitialized;
 }
 
-QList<Core::IOptionsPage *> FormEditorW::optionsPages() const
+QList<Core::IOptionsPage *> FormEditorW::optionsPages()
 {
-    return m_settingsPages;
+    return d->m_settingsPages;
 }
 
 void FormEditorW::ensureInitStage(InitializationStage s)
 {
     if (Designer::Constants::Internal::debug)
         qDebug() << Q_FUNC_INFO << s;
-    if (!m_self)
-        m_self = new FormEditorW;
-    if (m_self->m_initStage >= s)
+    if (!d) {
+        m_instance = new FormEditorW;
+        d = new FormEditorData;
+    }
+    if (d->m_initStage >= s)
         return;
     QApplication::setOverrideCursor(Qt::WaitCursor);
-    m_self->fullInit();
+    d->fullInit();
     QApplication::restoreOverrideCursor();
 }
 
-FormEditorW *FormEditorW::instance()
-{
-    ensureInitStage(FullyInitialized);
-    return m_self;
-}
-
 void FormEditorW::deleteInstance()
 {
-    delete m_self;
+    delete d;
+    d = 0;
+    delete m_instance;
+    m_instance = 0;
 }
 
-void FormEditorW::setupActions()
+IEditor *FormEditorW::createEditor()
+{
+    ensureInitStage(FullyInitialized);
+    return d->createEditor();
+}
+
+void FormEditorData::setupActions()
 {
     //menus
     ActionContainer *medit = ActionManager::actionContainer(Core::Constants::M_EDIT);
@@ -420,9 +529,9 @@ void FormEditorW::setupActions()
     bindShortcut(ActionManager::registerAction(m_fwm->actionPaste(), Core::Constants::PASTE, m_contexts), m_fwm->actionPaste());
     bindShortcut(ActionManager::registerAction(m_fwm->actionSelectAll(), Core::Constants::SELECTALL, m_contexts), m_fwm->actionSelectAll());
 
-    m_actionPrint = new QAction(this);
+    m_actionPrint = new QAction(m_instance);
     bindShortcut(ActionManager::registerAction(m_actionPrint, Core::Constants::PRINT, m_contexts), m_actionPrint);
-    connect(m_actionPrint, SIGNAL(triggered()), this, SLOT(print()));
+    QObject::connect(m_actionPrint, &QAction::triggered, [this]() { print(); });
 
     //'delete' action. Do not set a shortcut as Designer handles
     // the 'Delete' key by event filter. Setting a shortcut triggers
@@ -433,9 +542,10 @@ void FormEditorW::setupActions()
     command->setAttribute(Command::CA_Hide);
     medit->addAction(command, Core::Constants::G_EDIT_COPYPASTE);
 
-    m_actionGroupEditMode = new QActionGroup(this);
+    m_actionGroupEditMode = new QActionGroup(m_instance);
     m_actionGroupEditMode->setExclusive(true);
-    connect(m_actionGroupEditMode, SIGNAL(triggered(QAction*)), this, SLOT(activateEditMode(QAction*)));
+    QObject::connect(m_actionGroupEditMode, &QActionGroup::triggered,
+            [this](QAction *a) { activateEditMode(a->data().toInt()); });
 
     medit->addSeparator(m_contexts, Core::Constants::G_EDIT_OTHER);
 
@@ -531,18 +641,23 @@ void FormEditorW::setupActions()
                   QString(), Core::Constants::G_DEFAULT_THREE);
 
     mformtools->addSeparator(m_contexts, Core::Constants::G_DEFAULT_THREE);
-    m_actionAboutPlugins = new QAction(tr("About Qt Designer Plugins..."), this);
+    m_actionAboutPlugins = new QAction(tr("About Qt Designer Plugins..."), m_instance);
     m_actionAboutPlugins->setMenuRole(QAction::NoRole);
     addToolAction(m_actionAboutPlugins, m_contexts, "FormEditor.AboutPlugins", mformtools,
                   QString(), Core::Constants::G_DEFAULT_THREE);
-    connect(m_actionAboutPlugins,  SIGNAL(triggered()), m_fwm, SLOT(showPluginDialog()));
+    QObject::connect(m_actionAboutPlugins, &QAction::triggered,
+        m_fwm, &QDesignerFormWindowManagerInterface::showPluginDialog);
     m_actionAboutPlugins->setEnabled(false);
 
     // FWM
-    connect(m_fwm, SIGNAL(activeFormWindowChanged(QDesignerFormWindowInterface*)), this, SLOT(activeFormWindowChanged(QDesignerFormWindowInterface*)));
+    QObject::connect(m_fwm, &QDesignerFormWindowManagerInterface::activeFormWindowChanged,
+        [this] (QDesignerFormWindowInterface *afw) {
+            m_fwm->closeAllPreviews();
+            setPreviewMenuEnabled(afw != 0);
+        });
 }
 
-QToolBar *FormEditorW::createEditorToolBar() const
+QToolBar *FormEditorData::createEditorToolBar() const
 {
     QToolBar *editorToolBar = new QToolBar;
     const QList<Id>::const_iterator cend = m_toolActionIds.constEnd();
@@ -559,7 +674,7 @@ QToolBar *FormEditorW::createEditorToolBar() const
     return editorToolBar;
 }
 
-ActionContainer *FormEditorW::createPreviewStyleMenu(QActionGroup *actionGroup)
+ActionContainer *FormEditorData::createPreviewStyleMenu(QActionGroup *actionGroup)
 {
     const QString menuId = QLatin1String(M_FORMEDITOR_PREVIEW);
     ActionContainer *menuPreviewStyle = ActionManager::createMenu(M_FORMEDITOR_PREVIEW);
@@ -595,36 +710,36 @@ ActionContainer *FormEditorW::createPreviewStyleMenu(QActionGroup *actionGroup)
     return menuPreviewStyle;
 }
 
-void FormEditorW::setPreviewMenuEnabled(bool e)
+void FormEditorData::setPreviewMenuEnabled(bool e)
 {
     m_actionPreview->setEnabled(e);
     m_previewInStyleMenu->setEnabled(e);
 }
 
-void FormEditorW::saveSettings(QSettings *s)
+void FormEditorData::saveSettings(QSettings *s)
 {
     s->beginGroup(QLatin1String(settingsGroupC));
     m_editorWidget->saveSettings(s);
     s->endGroup();
 }
 
-void FormEditorW::critical(const QString &errorMessage)
+void FormEditorData::critical(const QString &errorMessage)
 {
     QMessageBox::critical(ICore::mainWindow(), tr("Designer"),  errorMessage);
 }
 
 // Apply the command shortcut to the action and connects to the command's keySequenceChanged signal
-void FormEditorW::bindShortcut(Command *command, QAction *action)
+void FormEditorData::bindShortcut(Command *command, QAction *action)
 {
     m_commandToDesignerAction.insert(command, action);
-    connect(command, SIGNAL(keySequenceChanged()),
-            m_shortcutMapper, SLOT(map()));
-    m_shortcutMapper->setMapping(command, command);
+    QObject::connect(command, SIGNAL(keySequenceChanged()),
+                     &m_shortcutMapper, SLOT(map()));
+    m_shortcutMapper.setMapping(command, command);
     updateShortcut(command);
 }
 
 // Create an action to activate a designer tool
-QAction *FormEditorW::createEditModeAction(QActionGroup *ag,
+QAction *FormEditorData::createEditModeAction(QActionGroup *ag,
                                      const Context &context,
                                      ActionContainer *medit,
                                      const QString &actionName,
@@ -649,9 +764,9 @@ QAction *FormEditorW::createEditModeAction(QActionGroup *ag,
 }
 
 // Create a tool action
-Command *FormEditorW::addToolAction(QAction *a, const Context &context, Id id,
-                                          ActionContainer *c1, const QString &keySequence,
-                                    Core::Id groupId)
+Command *FormEditorData::addToolAction(QAction *a, const Context &context, Id id,
+                                       ActionContainer *c1, const QString &keySequence,
+                                       Core::Id groupId)
 {
     Command *command = ActionManager::registerAction(a, id, context);
     if (!keySequence.isEmpty())
@@ -662,31 +777,60 @@ Command *FormEditorW::addToolAction(QAction *a, const Context &context, Id id,
     return command;
 }
 
-EditorData FormEditorW::createEditor()
+Core::IEditor *FormEditorData::createEditor()
 {
     if (Designer::Constants::Internal::debug)
         qDebug() << "FormEditorW::createEditor";
     // Create and associate form and text editor.
-    EditorData data;
     m_fwm->closeAllPreviews();
     QDesignerFormWindowInterface *form = m_fwm->createFormWindow(0);
-    QTC_ASSERT(form, return data);
-    connect(form, SIGNAL(toolChanged(int)), this, SLOT(toolChanged(int)));
+    QTC_ASSERT(form, return 0);
+    QObject::connect(form, &QDesignerFormWindowInterface::toolChanged, [this] (int i) { toolChanged(i); });
 
-    m_xmlEditorFactory->m_form = form;
-    ResourceHandler *resourceHandler = new ResourceHandler(form);
-    data.widgetHost = new SharedTools::WidgetHost( /* parent */ 0, form);
-    data.formWindowEditor = qobject_cast<FormWindowEditor *>(m_xmlEditorFactory->createEditor());
-    connect(data.formWindowEditor->textDocument(), SIGNAL(filePathChanged(QString,QString)),
-            resourceHandler, SLOT(updateResources()));
-    m_editorWidget->add(data);
+    SharedTools::WidgetHost *widgetHost = new SharedTools::WidgetHost( /* parent */ 0, form);
+    FormWindowEditor *formWindowEditor = m_xmlEditorFactory->create(form);
 
-    m_toolBar->addEditor(data.formWindowEditor);
+    m_editorWidget->add(widgetHost, formWindowEditor);
+    m_toolBar->addEditor(formWindowEditor);
 
-    return data;
+    if (formWindowEditor) {
+        Core::InfoBarEntry info(Core::Id(Constants::INFO_READ_ONLY),
+                                tr("This file can only be edited in <b>Design</b> mode."));
+        info.setCustomButtonInfo(tr("Switch Mode"), []() { ModeManager::activateMode(Core::Constants::MODE_DESIGN); });
+        formWindowEditor->document()->infoBar()->addInfo(info);
+    }
+    return formWindowEditor;
 }
 
-void FormEditorW::updateShortcut(QObject *command)
+QDesignerFormEditorInterface *FormEditorW::designerEditor()
+{
+    ensureInitStage(FullyInitialized);
+    return d->m_formeditor;
+}
+
+QWidget * const *FormEditorW::designerSubWindows()
+{
+    ensureInitStage(SubwindowsInitialized);
+    return d->m_designerSubWindows;
+}
+
+SharedTools::WidgetHost *FormEditorW::activeWidgetHost()
+{
+    ensureInitStage(FullyInitialized);
+    if (d->m_editorWidget)
+        return d->m_editorWidget->activeEditor().widgetHost;
+    return 0;
+}
+
+FormWindowEditor *FormEditorW::activeEditor()
+{
+    ensureInitStage(FullyInitialized);
+    if (d->m_editorWidget)
+        return d->m_editorWidget->activeEditor().formWindowEditor;
+    return 0;
+}
+
+void FormEditorData::updateShortcut(QObject *command)
 {
     Command *c = qobject_cast<Command *>(command);
     if (!c)
@@ -697,51 +841,14 @@ void FormEditorW::updateShortcut(QObject *command)
     a->setShortcut(c->action()->shortcut());
 }
 
-void FormEditorW::currentEditorChanged(IEditor *editor)
-{
-    if (Designer::Constants::Internal::debug)
-        qDebug() << Q_FUNC_INFO << editor << " of " << m_fwm->formWindowCount();
-
-    if (editor && editor->document()->id() == Constants::K_DESIGNER_XML_EDITOR_ID) {
-        FormWindowEditor *xmlEditor = qobject_cast<FormWindowEditor *>(editor);
-        QTC_ASSERT(xmlEditor, return);
-        ensureInitStage(FullyInitialized);
-        SharedTools::WidgetHost *fw = m_editorWidget->formWindowEditorForXmlEditor(xmlEditor);
-        QTC_ASSERT(fw, return);
-        m_editorWidget->setVisibleEditor(xmlEditor);
-        m_fwm->setActiveFormWindow(fw->formWindow());
-    }
-}
-
-void FormEditorW::activeFormWindowChanged(QDesignerFormWindowInterface *afw)
-{
-    if (Designer::Constants::Internal::debug)
-        qDebug() << Q_FUNC_INFO << afw << " of " << m_fwm->formWindowCount();
-
-    m_fwm->closeAllPreviews();
-    setPreviewMenuEnabled(afw != 0);
-}
-
-EditorData FormEditorW::activeEditor() const
-{
-    if (m_editorWidget)
-        return m_editorWidget->activeEditor();
-    return EditorData();
-}
-
-void FormEditorW::activateEditMode(int id)
+void FormEditorData::activateEditMode(int id)
 {
     if (const int count = m_fwm->formWindowCount())
         for (int i = 0; i <  count; i++)
              m_fwm->formWindow(i)->setCurrentTool(id);
 }
 
-void FormEditorW::activateEditMode(QAction* a)
-{
-    activateEditMode(a->data().toInt());
-}
-
-void FormEditorW::toolChanged(int t)
+void FormEditorData::toolChanged(int t)
 {
     typedef QList<QAction *> ActionList;
     if (const QAction *currentAction = m_actionGroupEditMode->checkedAction())
@@ -756,13 +863,7 @@ void FormEditorW::toolChanged(int t)
         }
 }
 
-void FormEditorW::closeFormEditorsForXmlEditors(QList<IEditor*> editors)
-{
-    foreach (IEditor *editor, editors)
-        m_editorWidget->removeFormWindowEditor(editor);
-}
-
-void FormEditorW::print()
+void FormEditorData::print()
 {
     // Printing code courtesy of designer_actions.cpp
     QDesignerFormWindowInterface *fw = m_fwm->activeFormWindow();
diff --git a/src/plugins/designer/formeditorw.h b/src/plugins/designer/formeditorw.h
index 2cfc601b89a..b55291435f9 100644
--- a/src/plugins/designer/formeditorw.h
+++ b/src/plugins/designer/formeditorw.h
@@ -35,42 +35,18 @@
 #include <coreplugin/icontext.h>
 #include <coreplugin/dialogs/ioptionspage.h>
 
-#include <QMap>
-#include <QObject>
-
 QT_BEGIN_NAMESPACE
-
-class QDesignerIntegrationInterface;
 class QDesignerFormEditorInterface;
-class QDesignerFormWindowInterface;
-class QDesignerFormWindowManagerInterface;
-
-class QAction;
-class QActionGroup;
-class QMenu;
-class QSignalMapper;
-class QSettings;
-class QToolBar;
-
 QT_END_NAMESPACE
 
-namespace Core {
-class ActionManager;
-class ActionContainer;
-class Command;
-class IEditor;
-class Id;
-class DesignMode;
-class EditorToolBar;
-}
+namespace Core { class IEditor; }
+namespace SharedTools { class WidgetHost; }
 
 namespace Designer {
-namespace Internal {
 
-class EditorData;
-class EditorWidget;
-class SettingsPage;
-class DesignerContext;
+class FormWindowEditor;
+
+namespace Internal {
 
 /** FormEditorW is a singleton that stores the Designer CoreInterface and
   * performs centralized operations. The instance() function will return an
@@ -88,107 +64,29 @@ class DesignerContext;
   * in Design mode. */
 class FormEditorW : public QObject
 {
-    Q_OBJECT
 public:
     enum InitializationStage {
         // Register Creator plugins (settings pages, actions)
         RegisterPlugins,
+        // Subwindows of the designer are initialized
+        SubwindowsInitialized,
         // Fully initialized for handling editor requests
         FullyInitialized
     };
 
-    virtual ~FormEditorW();
-
     // Create an instance and initialize up to stage s
     static void ensureInitStage(InitializationStage s);
-    // Returns fully initialized instance
-    static FormEditorW *instance();
     // Deletes an existing instance if there is one.
     static void deleteInstance();
 
-    EditorData createEditor();
+    static Core::IEditor *createEditor();
 
-    inline QDesignerFormEditorInterface *designerEditor() const { return m_formeditor; }
-    inline QWidget * const*designerSubWindows() const { return m_designerSubWindows; }
+    static QDesignerFormEditorInterface *designerEditor();
+    static QWidget * const *designerSubWindows();
 
-    EditorData activeEditor() const;
-    QList<Core::IOptionsPage *> optionsPages() const;
-
-private slots:
-    void activateEditMode(int id);
-    void activateEditMode(QAction*);
-    void activeFormWindowChanged(QDesignerFormWindowInterface *);
-    void currentEditorChanged(Core::IEditor *editor);
-    void toolChanged(int);
-    void print();
-    void setPreviewMenuEnabled(bool e);
-    void updateShortcut(QObject *command);
-    void closeFormEditorsForXmlEditors(QList<Core::IEditor*> editors);
-
-private:
-    FormEditorW();
-    void fullInit();
-
-    void saveSettings(QSettings *s);
-
-    void initDesignerSubWindows();
-
-    void setupActions();
-    void setupViewActions();
-    void addDockViewAction(Core::ActionContainer *viewMenu,
-                           int index,
-                           const Core::Context &context,
-                           const QString &title, Core::Id id);
-
-    Core::ActionContainer *createPreviewStyleMenu(QActionGroup *actionGroup);
-
-    void critical(const QString &errorMessage);
-    void bindShortcut(Core::Command *command, QAction *action);
-    QAction *createEditModeAction(QActionGroup *ag,
-                                         const Core::Context &context,
-                                         Core::ActionContainer *medit,
-                                         const QString &actionName,
-                                         Core::Id id,
-                                         int toolNumber,
-                                         const QString &iconName = QString(),
-                                         const QString &keySequence = QString());
-    Core::Command *addToolAction(QAction *a,
-                                 const Core::Context &context, Core::Id id,
-                                 Core::ActionContainer *c1, const QString &keySequence = QString(),
-                                 Core::Id groupId = Core::Id());
-    QToolBar *createEditorToolBar() const;
-
-    QDesignerFormEditorInterface *m_formeditor;
-    QDesignerIntegrationInterface *m_integration;
-    QDesignerFormWindowManagerInterface *m_fwm;
-    InitializationStage m_initStage;
-
-    QWidget *m_designerSubWindows[Designer::Constants::DesignerSubWindowCount];
-
-    QAction *m_lockAction;
-    QAction *m_resetLayoutAction;
-
-    QList<Core::IOptionsPage *> m_settingsPages;
-    QActionGroup *m_actionGroupEditMode;
-    QAction *m_actionPrint;
-    QAction *m_actionPreview;
-    QActionGroup *m_actionGroupPreviewInStyle;
-    QMenu *m_previewInStyleMenu;
-    QAction *m_actionAboutPlugins;
-    QSignalMapper *m_shortcutMapper;
-
-    DesignerContext *m_context;
-    Core::Context m_contexts;
-
-    QList<Core::Id> m_toolActionIds;
-    QWidget *m_modeWidget;
-    EditorWidget *m_editorWidget;
-    Core::DesignMode *m_designMode;
-
-    QWidget *m_editorToolBar;
-    Core::EditorToolBar *m_toolBar;
-
-    QMap<Core::Command *, QAction *> m_commandToDesignerAction;
+    static SharedTools::WidgetHost *activeWidgetHost();
+    static FormWindowEditor *activeEditor();
+    static QList<Core::IOptionsPage *> optionsPages();
 };
 
 } // namespace Internal
diff --git a/src/plugins/designer/formtemplatewizardpage.cpp b/src/plugins/designer/formtemplatewizardpage.cpp
index d52d41d1309..63f2cdd6146 100644
--- a/src/plugins/designer/formtemplatewizardpage.cpp
+++ b/src/plugins/designer/formtemplatewizardpage.cpp
@@ -51,7 +51,7 @@ namespace Internal {
 
 FormTemplateWizardPage::FormTemplateWizardPage(QWidget * parent) :
     QWizardPage(parent),
-    m_newFormWidget(QDesignerNewFormWidgetInterface::createNewFormWidget(FormEditorW::instance()->designerEditor())),
+    m_newFormWidget(QDesignerNewFormWidgetInterface::createNewFormWidget(FormEditorW::designerEditor())),
     m_templateSelected(m_newFormWidget->hasCurrentTemplate())
 {
     setTitle(tr("Choose a Form Template"));
diff --git a/src/plugins/designer/formwindoweditor.cpp b/src/plugins/designer/formwindoweditor.cpp
index 4726866daf5..be12d55b194 100644
--- a/src/plugins/designer/formwindoweditor.cpp
+++ b/src/plugins/designer/formwindoweditor.cpp
@@ -44,6 +44,8 @@
 
 namespace Designer {
 
+using namespace Internal;
+
 FormWindowEditor::FormWindowEditor()
 {
     addContext(Designer::Constants::K_DESIGNER_XML_EDITOR_ID);
@@ -57,7 +59,7 @@ FormWindowEditor::~FormWindowEditor()
 void FormWindowEditor::finalizeInitialization()
 {
     // Revert to saved/load externally modified files.
-    connect(formWindowFile(), &Internal::FormWindowFile::reloadRequested,
+    connect(formWindowFile(), &FormWindowFile::reloadRequested,
             [this](QString *errorString, const QString &fileName) {
                 open(errorString, fileName, fileName);
     });
@@ -68,7 +70,8 @@ bool FormWindowEditor::open(QString *errorString, const QString &fileName, const
     if (Designer::Constants::Internal::debug)
         qDebug() << "FormWindowEditor::open" << fileName;
 
-    QDesignerFormWindowInterface *form = formWindowFile()->formWindow();
+    auto document = qobject_cast<FormWindowFile *>(textDocument());
+    QDesignerFormWindowInterface *form = document->formWindow();
     QTC_ASSERT(form, return false);
 
     if (fileName.isEmpty())
@@ -78,7 +81,7 @@ bool FormWindowEditor::open(QString *errorString, const QString &fileName, const
     const QString absfileName = fi.absoluteFilePath();
 
     QString contents;
-    if (formWindowFile()->read(absfileName, &contents, errorString) != Utils::TextFileFormat::ReadSuccess)
+    if (document->read(absfileName, &contents, errorString) != Utils::TextFileFormat::ReadSuccess)
         return false;
 
     form->setFileName(absfileName);
@@ -90,12 +93,10 @@ bool FormWindowEditor::open(QString *errorString, const QString &fileName, const
         return false;
     form->setDirty(fileName != realFileName);
 
-    formWindowFile()->syncXmlFromFormWindow();
-    formWindowFile()->setFilePath(absfileName);
-    formWindowFile()->setShouldAutoSave(false);
-
-    if (Internal::ResourceHandler *rh = form->findChild<Designer::Internal::ResourceHandler*>())
-        rh->updateResources(true);
+    document->syncXmlFromFormWindow();
+    document->setFilePath(absfileName);
+    document->setShouldAutoSave(false);
+    document->resourceHandler()->updateResources(true);
 
     return true;
 }
@@ -110,9 +111,9 @@ QString FormWindowEditor::contents() const
     return formWindowFile()->formWindowContents();
 }
 
-Internal::FormWindowFile *FormWindowEditor::formWindowFile() const
+FormWindowFile *FormWindowEditor::formWindowFile() const
 {
-    return qobject_cast<Internal::FormWindowFile *>(textDocument());
+    return qobject_cast<FormWindowFile *>(textDocument());
 }
 
 bool FormWindowEditor::isDesignModePreferred() const
diff --git a/src/plugins/designer/formwindowfile.cpp b/src/plugins/designer/formwindowfile.cpp
index 26fe21d5891..4485acd0adc 100644
--- a/src/plugins/designer/formwindowfile.cpp
+++ b/src/plugins/designer/formwindowfile.cpp
@@ -29,6 +29,7 @@
 
 #include "formwindowfile.h"
 #include "designerconstants.h"
+#include "resourcehandler.h"
 
 #include <utils/qtcassert.h>
 
@@ -60,6 +61,10 @@ FormWindowFile::FormWindowFile(QDesignerFormWindowInterface *form, QObject *pare
     connect(m_formWindow->commandHistory(), SIGNAL(indexChanged(int)),
             this, SLOT(setShouldAutoSave()));
     connect(m_formWindow, SIGNAL(changed()), SLOT(updateIsModified()));
+
+    m_resourceHandler = new ResourceHandler(form);
+    connect(this, SIGNAL(filePathChanged(QString,QString)),
+            m_resourceHandler, SLOT(updateResources()));
 }
 
 bool FormWindowFile::save(QString *errorString, const QString &name, bool autoSave)
@@ -217,6 +222,11 @@ QString FormWindowFile::formWindowContents() const
     return m_formWindow->contents();
 }
 
+ResourceHandler *FormWindowFile::resourceHandler() const
+{
+    return m_resourceHandler;
+}
+
 void FormWindowFile::slotFormWindowRemoved(QDesignerFormWindowInterface *w)
 {
     // Release formwindow as soon as the FormWindowManager removes
diff --git a/src/plugins/designer/formwindowfile.h b/src/plugins/designer/formwindowfile.h
index 52060dd7493..5cde87bf630 100644
--- a/src/plugins/designer/formwindowfile.h
+++ b/src/plugins/designer/formwindowfile.h
@@ -41,6 +41,8 @@ QT_END_NAMESPACE
 namespace Designer {
 namespace Internal {
 
+class ResourceHandler;
+
 class FormWindowFile : public TextEditor::BaseTextDocument
 {
     Q_OBJECT
@@ -67,6 +69,7 @@ public:
     QDesignerFormWindowInterface *formWindow() const;
     void syncXmlFromFormWindow();
     QString formWindowContents() const;
+    ResourceHandler *resourceHandler() const;
 
 signals:
     // Internal
@@ -87,6 +90,7 @@ private:
     // to deleting the WidgetHost which owns it.
     QPointer<QDesignerFormWindowInterface> m_formWindow;
     bool m_isModified;
+    ResourceHandler *m_resourceHandler;
 };
 
 } // namespace Internal
diff --git a/src/plugins/designer/gotoslot_test.cpp b/src/plugins/designer/gotoslot_test.cpp
index 7814af028d3..edf5db07aef 100644
--- a/src/plugins/designer/gotoslot_test.cpp
+++ b/src/plugins/designer/gotoslot_test.cpp
@@ -172,8 +172,7 @@ public:
         waitForFilesInGlobalSnapshot(QStringList() << cppFile << hFile);
 
         // Execute "Go To Slot"
-        FormEditorW *few = FormEditorW::instance();
-        QDesignerIntegrationInterface *integration = few->designerEditor()->integration();
+        QDesignerIntegrationInterface *integration = FormEditorW::designerEditor()->integration();
         QVERIFY(integration);
         integration->emitNavigateToSlot(QLatin1String("pushButton"), QLatin1String("clicked()"),
                                         QStringList());
diff --git a/src/plugins/designer/qtcreatorintegration.cpp b/src/plugins/designer/qtcreatorintegration.cpp
index d00064ba3a5..3699fff1b1d 100644
--- a/src/plugins/designer/qtcreatorintegration.cpp
+++ b/src/plugins/designer/qtcreatorintegration.cpp
@@ -76,9 +76,8 @@ static QString msgClassNotFound(const QString &uiClassName, const QList<Document
         .arg(uiClassName, files);
 }
 
-QtCreatorIntegration::QtCreatorIntegration(QDesignerFormEditorInterface *core, FormEditorW *parent) :
-    QDesignerIntegration(core, parent),
-    m_few(parent)
+QtCreatorIntegration::QtCreatorIntegration(QDesignerFormEditorInterface *core, QObject *parent)
+    : QDesignerIntegration(core, parent)
 {
     setResourceFileWatcherBehaviour(ReloadResourceFileSilently);
     Feature f = features();
@@ -103,15 +102,15 @@ void QtCreatorIntegration::slotDesignerHelpRequested(const QString &manual, cons
 
 void QtCreatorIntegration::updateSelection()
 {
-    if (const EditorData ed = m_few->activeEditor())
-        ed.widgetHost->updateFormWindowSelectionHandles(true);
+    if (SharedTools::WidgetHost *host = FormEditorW::activeWidgetHost())
+        host->updateFormWindowSelectionHandles(true);
     QDesignerIntegration::updateSelection();
 }
 
 QWidget *QtCreatorIntegration::containerWindow(QWidget * /*widget*/) const
 {
-    if (const EditorData ed = m_few->activeEditor())
-        return ed.widgetHost->integrationContainer();
+    if (SharedTools::WidgetHost *host = FormEditorW::activeWidgetHost())
+        return host->integrationContainer();
     return 0;
 }
 
@@ -467,7 +466,7 @@ void QtCreatorIntegration::slotNavigateToSlot(const QString &objectName, const Q
 {
     QString errorMessage;
     if (!navigateToSlot(objectName, signalSignature, parameterNames, &errorMessage) && !errorMessage.isEmpty())
-        QMessageBox::warning(m_few->designerEditor()->topLevel(), tr("Error finding/adding a slot."), errorMessage);
+        QMessageBox::warning(FormEditorW::designerEditor()->topLevel(), tr("Error finding/adding a slot."), errorMessage);
 }
 
 // Build name of the class as generated by uic, insert Ui namespace
@@ -510,9 +509,7 @@ bool QtCreatorIntegration::navigateToSlot(const QString &objectName,
 {
     typedef QMap<int, Document::Ptr> DocumentMap;
 
-    const EditorData ed = m_few->activeEditor();
-    QTC_ASSERT(ed, return false);
-    const QString currentUiFile = ed.formWindowEditor->document()->filePath();
+    const QString currentUiFile = FormEditorW::activeEditor()->document()->filePath();
 #if 0
     return Designer::Internal::navigateToSlot(currentUiFile, objectName, signalSignature, parameterNames, errorMessage);
 #endif
@@ -566,7 +563,7 @@ bool QtCreatorIntegration::navigateToSlot(const QString &objectName,
         return false;
     }
 
-    QDesignerFormWindowInterface *fwi = ed.widgetHost->formWindow();
+    QDesignerFormWindowInterface *fwi = FormEditorW::activeWidgetHost()->formWindow();
 
     const QString uiClass = uiClassName(fwi->mainContainer()->objectName());
 
diff --git a/src/plugins/designer/qtcreatorintegration.h b/src/plugins/designer/qtcreatorintegration.h
index 57489e4eec2..579c9610308 100644
--- a/src/plugins/designer/qtcreatorintegration.h
+++ b/src/plugins/designer/qtcreatorintegration.h
@@ -38,13 +38,12 @@ QT_FORWARD_DECLARE_CLASS(QUrl)
 namespace Designer {
 namespace Internal {
 
-class FormEditorW;
-
 class QtCreatorIntegration : public QDesignerIntegration
 {
     Q_OBJECT
+
 public:
-    explicit QtCreatorIntegration(QDesignerFormEditorInterface *core, FormEditorW *parent = 0);
+    explicit QtCreatorIntegration(QDesignerFormEditorInterface *core, QObject *parent = 0);
 
     QWidget *containerWindow(QWidget *widget) const;
 
@@ -66,7 +65,6 @@ private:
                         const QString &signalSignature,
                         const QStringList &parameterNames,
                         QString *errorMessage);
-    FormEditorW *m_few;
 };
 
 } // namespace Internal
diff --git a/src/plugins/designer/settingspage.cpp b/src/plugins/designer/settingspage.cpp
index ef471f08080..b6606e1c24e 100644
--- a/src/plugins/designer/settingspage.cpp
+++ b/src/plugins/designer/settingspage.cpp
@@ -84,7 +84,7 @@ QList<Core::IOptionsPage *> SettingsPageProvider::pages() const
         m_initialized = true;
         FormEditorW::ensureInitStage(FormEditorW::RegisterPlugins);
     }
-    return FormEditorW::instance()->optionsPages();
+    return FormEditorW::optionsPages();
 }
 
 bool SettingsPageProvider::matches(const QString &searchKeyWord) const