DesignMode: Apply 'static pattern'

Also:
 - and replace some occurrences of DesignMode::instance()->id() by
   Core::Constants::MODE_DESIGN for less dependence on the lifetime
   of the DesignMode object (and less indirection)
 - remove storage if DesignMode::instance() values when direct
   use of the static functions suffice
 - remove some unused items from the interface
 - use member-initialization in DesignMode::Private.

Change-Id: Ie66c06da0fc0a3ccc588b8079e51db6b39284152
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

9 files changed, 28 insertions, 50 deletions

diff --git a/src/plugins/coreplugin/coreplugin.cpp b/src/plugins/coreplugin/coreplugin.cpp
index 577a9f9487..379e198d13 100644
--- a/src/plugins/coreplugin/coreplugin.cpp
+++ b/src/plugins/coreplugin/coreplugin.cpp
@@ -91,7 +91,7 @@ CorePlugin::~CorePlugin()
     }
 
     if (m_designMode) {
-        if (m_designMode->designModeIsRequired())
+        if (DesignMode::designModeIsRequired())
             removeObject(m_designMode);
         delete m_designMode;
     }
@@ -226,7 +226,7 @@ bool CorePlugin::initialize(const QStringList &arguments, QString *errorMessage)
 
 void CorePlugin::extensionsInitialized()
 {
-    if (m_designMode->designModeIsRequired())
+    if (DesignMode::designModeIsRequired())
         addObject(m_designMode);
     Find::extensionsInitialized();
     m_locator->extensionsInitialized();
diff --git a/src/plugins/coreplugin/designmode.cpp b/src/plugins/coreplugin/designmode.cpp
index 08d3ec20e6..33a016129c 100644
--- a/src/plugins/coreplugin/designmode.cpp
+++ b/src/plugins/coreplugin/designmode.cpp
@@ -40,8 +40,6 @@
 
 #include <QStackedWidget>
 
-static Core::DesignMode *m_instance = 0;
-
 namespace Core {
 
 struct DesignEditorInfo
@@ -60,17 +58,15 @@ public:
 
 public:
     QPointer<IEditor> m_currentEditor;
-    bool m_isActive;
-    bool m_isRequired;
+    bool m_isActive = false;
+    bool m_isRequired = false;
     QList<DesignEditorInfo*> m_editors;
     QStackedWidget *m_stackWidget;
     Context m_activeContext;
 };
 
 DesignModePrivate::DesignModePrivate()
-    : m_isActive(false),
-      m_isRequired(false),
-      m_stackWidget(new QStackedWidget)
+    : m_stackWidget(new QStackedWidget)
 {}
 
 DesignModePrivate::~DesignModePrivate()
@@ -78,10 +74,13 @@ DesignModePrivate::~DesignModePrivate()
     delete m_stackWidget;
 }
 
+static DesignMode *m_instance = nullptr;
+static DesignModePrivate *d = nullptr;
+
 DesignMode::DesignMode()
-    : d(new DesignModePrivate)
 {
     m_instance = this;
+    d = new DesignModePrivate;
 
     ICore::addPreCloseListener([]() -> bool {
         m_instance->currentEditorChanged(0);
@@ -121,19 +120,11 @@ void DesignMode::setDesignModeIsRequired()
     d->m_isRequired = true;
 }
 
-bool DesignMode::designModeIsRequired() const
+bool DesignMode::designModeIsRequired()
 {
     return d->m_isRequired;
 }
 
-QStringList DesignMode::registeredMimeTypes() const
-{
-    QStringList rc;
-    foreach (const DesignEditorInfo *i, d->m_editors)
-        rc += i->mimeTypes;
-    return rc;
-}
-
 /**
   * Registers a widget to be displayed when an editor with a file specified in
   * mimeTypes is opened. This also appends the additionalContext in ICore to
diff --git a/src/plugins/coreplugin/designmode.h b/src/plugins/coreplugin/designmode.h
index fc0be09ed0..0bda118c74 100644
--- a/src/plugins/coreplugin/designmode.h
+++ b/src/plugins/coreplugin/designmode.h
@@ -30,8 +30,6 @@
 namespace Core {
 class IEditor;
 
-namespace Internal { class DesignModeCoreListener; }
-
 /**
   * A global mode for Design pane - used by Bauhaus (QML Designer) and
   * Qt Designer. Other plugins can register themselves by registerDesignWidget()
@@ -39,8 +37,6 @@ namespace Internal { class DesignModeCoreListener; }
   * to the main editor widget itself.
   */
 
-class DesignModePrivate;
-
 class CORE_EXPORT DesignMode : public IMode
 {
     Q_OBJECT
@@ -51,15 +47,13 @@ public:
 
     static DesignMode *instance();
 
-    void setDesignModeIsRequired();
-    bool designModeIsRequired() const;
+    static void setDesignModeIsRequired();
+    static bool designModeIsRequired();
 
-    void registerDesignWidget(QWidget *widget,
-                              const QStringList &mimeTypes,
-                              const Context &context);
-    void unregisterDesignWidget(QWidget *widget);
-
-    QStringList registeredMimeTypes() const;
+    static void registerDesignWidget(QWidget *widget,
+                                     const QStringList &mimeTypes,
+                                     const Context &context);
+    static void unregisterDesignWidget(QWidget *widget);
 
 signals:
     void actionsUpdated(Core::IEditor *editor);
@@ -70,9 +64,6 @@ private:
     void currentEditorChanged(IEditor *editor);
     void updateContext(Id newMode, Id oldMode);
     void setActiveContext(const Context &context);
-
-    DesignModePrivate *d;
-    friend class Internal::DesignModeCoreListener;
 };
 
 } // namespace Core
diff --git a/src/plugins/designer/formeditorplugin.cpp b/src/plugins/designer/formeditorplugin.cpp
index 7edde10be9..2b9843d64b 100644
--- a/src/plugins/designer/formeditorplugin.cpp
+++ b/src/plugins/designer/formeditorplugin.cpp
@@ -117,7 +117,7 @@ bool FormEditorPlugin::initialize(const QStringList &arguments, QString *error)
 
 void FormEditorPlugin::extensionsInitialized()
 {
-    DesignMode::instance()->setDesignModeIsRequired();
+    DesignMode::setDesignModeIsRequired();
     // 4) test and make sure everything works (undo, saving, editors, opening/closing multiple files, dirtiness etc)
 
     ActionContainer *mtools = ActionManager::actionContainer(Core::Constants::M_TOOLS);
diff --git a/src/plugins/designer/formeditorw.cpp b/src/plugins/designer/formeditorw.cpp
index e526c2f937..43e3149550 100644
--- a/src/plugins/designer/formeditorw.cpp
+++ b/src/plugins/designer/formeditorw.cpp
@@ -215,7 +215,6 @@ public:
     QList<Id> m_toolActionIds;
     QWidget *m_modeWidget = nullptr;
     EditorWidget *m_editorWidget = nullptr;
-    DesignMode *m_designMode = nullptr;
 
     QWidget *m_editorToolBar = nullptr;
     EditorToolBar *m_toolBar = nullptr;
@@ -283,7 +282,7 @@ FormEditorData::~FormEditorData()
         m_editorWidget->saveSettings(s);
         s->endGroup();
 
-        m_designMode->unregisterDesignWidget(m_modeWidget);
+        DesignMode::unregisterDesignWidget(m_modeWidget);
         delete m_modeWidget;
         m_modeWidget = nullptr;
     }
@@ -406,7 +405,6 @@ void FormEditorData::fullInit()
     m_toolBar->setNavigationVisible(false);
     m_toolBar->addCenterToolBar(m_editorToolBar);
 
-    m_designMode = DesignMode::instance();
     m_modeWidget = new QWidget;
     m_modeWidget->setObjectName("DesignerModeWidget");
     QVBoxLayout *layout = new QVBoxLayout;
@@ -417,7 +415,7 @@ void FormEditorData::fullInit()
     // 'Run' in 'Design' mode emits output.
     MiniSplitter *splitter = new MiniSplitter(Qt::Vertical);
     splitter->addWidget(m_editorWidget);
-    QWidget *outputPane = new OutputPanePlaceHolder(m_designMode->id(), splitter);
+    QWidget *outputPane = new OutputPanePlaceHolder(Core::Constants::MODE_DESIGN, splitter);
     outputPane->setObjectName("DesignerOutputPanePlaceHolder");
     splitter->addWidget(outputPane);
     layout->addWidget(splitter);
@@ -428,7 +426,7 @@ void FormEditorData::fullInit()
     m_context = new DesignerContext(designerContexts, m_modeWidget, m_instance);
     ICore::addContextObject(m_context);
 
-    m_designMode->registerDesignWidget(m_modeWidget, QStringList(FORM_MIMETYPE), m_contexts);
+    DesignMode::registerDesignWidget(m_modeWidget, QStringList(FORM_MIMETYPE), m_contexts);
 
     setupViewActions();
 
diff --git a/src/plugins/qmldesigner/qmldesignerplugin.cpp b/src/plugins/qmldesigner/qmldesignerplugin.cpp
index a300537bec..21fd06824a 100644
--- a/src/plugins/qmldesigner/qmldesignerplugin.cpp
+++ b/src/plugins/qmldesigner/qmldesignerplugin.cpp
@@ -117,7 +117,7 @@ static bool checkIfEditorIsQtQuick(Core::IEditor *editor)
 
 static bool isDesignerMode(Core::Id mode)
 {
-    return mode == Core::DesignMode::instance()->id();
+    return mode == Core::Constants::MODE_DESIGN;
 }
 
 static bool documentIsAlreadyOpen(DesignDocument *designDocument, Core::IEditor *editor, Core::Id newMode)
@@ -158,7 +158,7 @@ QmlDesignerPlugin::QmlDesignerPlugin()
 QmlDesignerPlugin::~QmlDesignerPlugin()
 {
     if (d) {
-        Core::DesignMode::instance()->unregisterDesignWidget(d->mainWidget);
+        Core::DesignMode::unregisterDesignWidget(d->mainWidget);
         Core::ICore::removeContextObject(d->context);
         d->context = nullptr;
     }
@@ -251,7 +251,7 @@ void QmlDesignerPlugin::integrateIntoQtCreator(QWidget *modeWidget)
     const QStringList mimeTypes = { QmlJSTools::Constants::QML_MIMETYPE,
                                     QmlJSTools::Constants::QMLUI_MIMETYPE };
 
-    Core::DesignMode::instance()->registerDesignWidget(modeWidget, mimeTypes, d->context->context());
+    Core::DesignMode::registerDesignWidget(modeWidget, mimeTypes, d->context->context());
 
     connect(Core::DesignMode::instance(), &Core::DesignMode::actionsUpdated,
         &d->shortCutManager, &ShortCutManager::updateActions);
diff --git a/src/plugins/scxmleditor/scxmleditordata.cpp b/src/plugins/scxmleditor/scxmleditordata.cpp
index 49171fe146..c40639af48 100644
--- a/src/plugins/scxmleditor/scxmleditordata.cpp
+++ b/src/plugins/scxmleditor/scxmleditordata.cpp
@@ -118,7 +118,7 @@ ScxmlEditorData::~ScxmlEditorData()
         ICore::removeContextObject(m_context);
 
     if (m_modeWidget) {
-        m_designMode->unregisterDesignWidget(m_modeWidget);
+        DesignMode::unregisterDesignWidget(m_modeWidget);
         delete m_modeWidget;
         m_modeWidget = nullptr;
     }
@@ -132,7 +132,6 @@ void ScxmlEditorData::fullInit()
     m_widgetStack = new ScxmlEditorStack;
     m_widgetToolBar = new QToolBar;
     m_mainToolBar = createMainToolBar();
-    m_designMode = DesignMode::instance();
     m_modeWidget = createModeWidget();
 
     // Create undo/redo group/actions
@@ -153,7 +152,7 @@ void ScxmlEditorData::fullInit()
     m_context = new ScxmlContext(scxmlContexts, m_modeWidget, this);
     ICore::addContextObject(m_context);
 
-    m_designMode->registerDesignWidget(m_modeWidget, QStringList(QLatin1String(ProjectExplorer::Constants::SCXML_MIMETYPE)), m_contexts);
+    DesignMode::registerDesignWidget(m_modeWidget, QStringList(QLatin1String(ProjectExplorer::Constants::SCXML_MIMETYPE)), m_contexts);
 }
 
 IEditor *ScxmlEditorData::createEditor()
@@ -232,7 +231,7 @@ QWidget *ScxmlEditorData::createModeWidget()
     // 'Run' in 'Design' mode emits output.
     auto splitter = new MiniSplitter(Qt::Vertical);
     splitter->addWidget(m_widgetStack);
-    auto outputPane = new OutputPanePlaceHolder(m_designMode->id(), splitter);
+    auto outputPane = new OutputPanePlaceHolder(Core::Constants::MODE_DESIGN, splitter);
     outputPane->setObjectName("DesignerOutputPanePlaceHolder");
     splitter->addWidget(outputPane);
     layout->addWidget(splitter);
diff --git a/src/plugins/scxmleditor/scxmleditordata.h b/src/plugins/scxmleditor/scxmleditordata.h
index 785e927531..cbe35cfd41 100644
--- a/src/plugins/scxmleditor/scxmleditordata.h
+++ b/src/plugins/scxmleditor/scxmleditordata.h
@@ -29,8 +29,8 @@
 #include <QUndoGroup>
 
 #include <QCoreApplication>
-#include <coreplugin/designmode.h>
 #include <coreplugin/editortoolbar.h>
+#include <coreplugin/icontext.h>
 
 using namespace Core;
 
@@ -61,7 +61,6 @@ private:
     Context m_contexts;
     QWidget *m_modeWidget = nullptr;
     ScxmlEditorStack *m_widgetStack = nullptr;
-    DesignMode *m_designMode = nullptr;
     QToolBar *m_widgetToolBar = nullptr;
     EditorToolBar *m_mainToolBar = nullptr;
     QUndoGroup *m_undoGroup = nullptr;
diff --git a/src/plugins/scxmleditor/scxmleditorplugin.cpp b/src/plugins/scxmleditor/scxmleditorplugin.cpp
index df5f355ff8..30bddf6b2f 100644
--- a/src/plugins/scxmleditor/scxmleditorplugin.cpp
+++ b/src/plugins/scxmleditor/scxmleditorplugin.cpp
@@ -58,7 +58,7 @@ bool ScxmlEditorPlugin::initialize(const QStringList &arguments, QString *errorS
 
 void ScxmlEditorPlugin::extensionsInitialized()
 {
-    DesignMode::instance()->setDesignModeIsRequired();
+    DesignMode::setDesignModeIsRequired();
 }
 
 ExtensionSystem::IPlugin::ShutdownFlag ScxmlEditorPlugin::aboutToShutdown()