QmlDesigner: Fix for toolbar

Task-number: QDS-9042, QDS-9040, QDS-9034, QDS-8956
Change-Id: I0639bbfdaa7475a277cbb247c7d85bf5b078a5aa
Reviewed-by: Pranta Ghosh Dastider <pranta.dastider@qt.io>
Reviewed-by: Henning Gründl <henning.gruendl@qt.io>

share/qtcreator/qmldesigner/statusbar/Main.qml

@@ -34,6 +34,7 @@ Item {
                 style: StudioTheme.Values.statusbarButtonStyle
                 buttonIcon: StudioTheme.Constants.settings_medium
                 onClicked: backend.triggerProjectSettings()
+                enabled: backend.isInDesignMode
             }
 
             Text {

share/qtcreator/qmldesigner/toolbar/Main.qml

@@ -30,10 +30,9 @@ Rectangle {
             anchors.verticalCenter: parent.verticalCenter
             anchors.left: parent.left
             anchors.leftMargin: 10
-            enabled: backend.isDesignModeEnabled
 
-            tooltip: qsTr("Switch to Design Mode.")
+            tooltip: backend.isDesignModeEnabled ? qsTr("Switch to Design Mode.") : qsTr("Switch to Welcome Mode.")
-            buttonIcon: StudioTheme.Constants.designMode_large
+            buttonIcon: backend.isDesignModeEnabled ? StudioTheme.Constants.designMode_large : StudioTheme.Constants.home_large
             onClicked: backend.triggerModeChange()
         }
 
@@ -60,6 +59,7 @@ Rectangle {
             anchors.leftMargin: 10
             buttonIcon: StudioTheme.Constants.home_large
             onClicked: backend.triggerModeChange()
+            tooltip: qsTr("Switch to Welcome Mode.")
         }
 
         ToolbarButton {

src/plugins/qmldesigner/components/toolbar/toolbarbackend.cpp

@@ -76,9 +76,14 @@ static void openUiFile()
 void ToolBarBackend::triggerModeChange()
 {
     QmlDesignerPlugin::emitUsageStatistics(Constants::EVENT_TOOLBAR_MODE_CHANGE);
-    QTimer::singleShot(0, []() { //Do not trigger mode change directly from QML
+    QTimer::singleShot(0, [this]() { //Do not trigger mode change directly from QML
         bool qmlFileOpen = false;
 
+        if (!projectOpened()) {
+            Core::ModeManager::activateMode(Core::Constants::MODE_WELCOME);
+            return;
+        }
+
         auto document = Core::EditorManager::currentDocument();
 
         if (document)
@@ -326,6 +331,7 @@ ToolBarBackend::ToolBarBackend(QObject *parent)
             [this](ProjectExplorer::Project *project) {
                 disconnect(m_kitConnection);
                 emit isQt6Changed();
+                emit projectOpenedChanged();
                 if (project) {
                     m_kitConnection = connect(project,
                                               &ProjectExplorer::Project::activeTargetChanged,
@@ -449,6 +455,11 @@ bool ToolBarBackend::isQt6() const
     return isQt6Project;
 }
 
+bool ToolBarBackend::projectOpened() const
+{
+    return ProjectExplorer::SessionManager::instance()->startupProject();
+}
+
 void ToolBarBackend::setupWorkspaces()
 {
     m_workspaces.clear();

src/plugins/qmldesigner/components/toolbar/toolbarbackend.h

@@ -81,6 +81,7 @@ class ToolBarBackend : public QObject
     Q_PROPERTY(QStringList kits READ kits NOTIFY kitsChanged)
     Q_PROPERTY(int currentKit READ currentKit NOTIFY currentKitChanged)
     Q_PROPERTY(bool isQt6 READ isQt6 NOTIFY isQt6Changed)
+    Q_PROPERTY(bool projectOpened READ projectOpened NOTIFY projectOpenedChanged)
 
 public:
     ToolBarBackend(QObject *parent  = nullptr);
@@ -123,6 +124,8 @@ public:
 
     bool isQt6() const;
 
+    bool projectOpened() const;
+
 signals:
     void navigationHistoryChanged();
     void openDocumentsChanged();
@@ -135,6 +138,7 @@ signals:
     void kitsChanged();
     void currentKitChanged();
     void isQt6Changed();
+    void projectOpenedChanged();
 
 private:
     void setupWorkspaces();