ADS: Set default minimum size on empty dock widget

* Set a default minimum size on empty dock widgets. Dock widgets are
  empty if their content minimum size isEmpty (width or height <= 0)
* Replace 0 with nullptr as return value
* Fix some code formatting

Task-number: QDS-11255
Change-Id: Ifa7320fd57e73367f71087232dedd939d19ae490
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>
Reviewed-by: Qt CI Patch Build Bot <ci_patchbuild_bot@qt.io>

src/libs/advanceddockingsystem/ads_globals.h

@@ -161,8 +161,8 @@ bool isSideBarArea(DockWidgetArea area);
 
 /**
  * Searches for the parent widget of the given type. Returns the parent widget of the given
- * widget or 0 if the widget is not child of any widget of type T.
+ * widget or nullptr if the widget is not child of any widget of type T.
- * It is not safe to use this function in in DockWidget because only the current dock widget has a
+ * It is not safe to use this function in DockWidget, because only the current dock widget has a
  * parent. All dock widgets that are not the current dock widget in a dock area have no parent.
  */
 template<class T>
@@ -171,12 +171,12 @@ T findParent(const QWidget *widget)
     QWidget *parentWidget = widget->parentWidget();
     while (parentWidget) {
         T parentImpl = qobject_cast<T>(parentWidget);
-        if (parentImpl) {
+        if (parentImpl)
             return parentImpl;
-        }
+
         parentWidget = parentWidget->parentWidget();
     }
-    return 0;
+    return nullptr;
 }
 
 /**

src/libs/advanceddockingsystem/docksplitter.cpp

@@ -50,10 +50,9 @@ bool DockSplitter::hasVisibleContent() const
 {
     // TODO Cache or precalculate this to speed up
     for (int i = 0; i < count(); ++i) {
-        if (!widget(i)->isHidden()) {
+        if (!widget(i)->isHidden())
             return true;
     }
-    }
 
     return false;
 }

src/plugins/qmldesigner/designmodewidget.cpp

@@ -70,6 +70,27 @@ static void hideToolButtons(QList<QToolButton*> &buttons)
         button->hide();
 }
 
+static void ensureMinimumSize(QWidget *widget)
+{
+    if (widget->minimumSize().isEmpty())
+        widget->setMinimumSize(widget->minimumSize().expandedTo(QSize(60, 60)));
+}
+
+static ADS::DockWidget *createDockWidget(QWidget *widget,
+                                         const QString &uniqueId,
+                                         const QString &title,
+                                         ADS::DockWidget::eMinimumSizeHintMode minimumSizeHintMode)
+{
+    ADS::DockWidget *dockWidget = new ADS::DockWidget(uniqueId);
+    dockWidget->setWidget(widget, ADS::DockWidget::ForceNoScrollArea);
+    dockWidget->setWindowTitle(title);
+    dockWidget->setMinimumSizeHintMode(minimumSizeHintMode);
+
+    widget->setObjectName(uniqueId); // Set unique id as object name
+
+    return dockWidget;
+}
+
 namespace QmlDesigner {
 namespace Internal {
 
@@ -308,15 +329,10 @@ void DesignModeWidget::setup()
         sheet += "QLabel { background-color: creatorTheme.DSsectionHeadBackground; }";
         navigationView.widget->setStyleSheet(Theme::replaceCssColors(QString::fromUtf8(sheet)));
 
-        // Create DockWidget
+        ensureMinimumSize(navigationView.widget);
-        ADS::DockWidget *dockWidget = new ADS::DockWidget(uniqueId);
-        dockWidget->setWidget(navigationView.widget, ADS::DockWidget::ForceNoScrollArea);
-        dockWidget->setWindowTitle(title);
-        dockWidget->setMinimumSizeHintMode(m_minimumSizeHintMode);
-        m_dockManager->addDockWidget(ADS::NoDockWidgetArea, dockWidget);
 
-        // Set unique id as object name
+        auto dockWidget = createDockWidget(navigationView.widget, uniqueId, title, m_minimumSizeHintMode);
-        navigationView.widget->setObjectName(uniqueId);
+        m_dockManager->addDockWidget(ADS::NoDockWidgetArea, dockWidget);
 
         // Create menu action
         auto command = Core::ActionManager::registerAction(dockWidget->toggleViewAction(),
@@ -328,19 +344,17 @@ void DesignModeWidget::setup()
 
     // Afterwards get all the other widgets
     for (const WidgetInfo &widgetInfo : viewManager().widgetInfos()) {
-        // Create DockWidget
+        ensureMinimumSize(widgetInfo.widget);
-        ADS::DockWidget *dockWidget = new ADS::DockWidget(widgetInfo.uniqueId);
+
-        dockWidget->setWidget(widgetInfo.widget, ADS::DockWidget::ForceNoScrollArea);
+        auto dockWidget = createDockWidget(widgetInfo.widget,
-        dockWidget->setWindowTitle(widgetInfo.tabName);
+                                           widgetInfo.uniqueId,
-        dockWidget->setMinimumSizeHintMode(m_minimumSizeHintMode);
+                                           widgetInfo.tabName,
+                                           m_minimumSizeHintMode);
         m_dockManager->addDockWidget(ADS::NoDockWidgetArea, dockWidget);
 
         // Add to view widgets
         m_viewWidgets.append(widgetInfo.widget);
 
-        // Set unique id as object name
-        widgetInfo.widget->setObjectName(widgetInfo.uniqueId);
-
         // Create menu action
         auto command = Core::ActionManager::registerAction(dockWidget->toggleViewAction(),
                                                            actionToggle.withSuffix(
@@ -354,14 +368,14 @@ void DesignModeWidget::setup()
     {
         const QString uniqueId = "OutputPane";
         auto outputPanePlaceholder = new Core::OutputPanePlaceHolder(Core::Constants::MODE_DESIGN);
-        m_outputPaneDockWidget = new ADS::DockWidget(uniqueId);
-        m_outputPaneDockWidget->setWidget(outputPanePlaceholder, ADS::DockWidget::ForceNoScrollArea);
-        m_outputPaneDockWidget->setWindowTitle(tr("Output"));
-        m_outputPaneDockWidget->setMinimumSizeHintMode(m_minimumSizeHintMode);
-        m_dockManager->addDockWidget(ADS::NoDockWidgetArea, m_outputPaneDockWidget);
 
-        // Set unique id as object name
+        ensureMinimumSize(outputPanePlaceholder);
-        outputPanePlaceholder->setObjectName(uniqueId);
+
+        m_outputPaneDockWidget = createDockWidget(outputPanePlaceholder,
+                                                  uniqueId,
+                                                  tr("Output"),
+                                                  m_minimumSizeHintMode);
+        m_dockManager->addDockWidget(ADS::NoDockWidgetArea, m_outputPaneDockWidget);
 
         // Create menu action
         auto command = Core::ActionManager::registerAction(m_outputPaneDockWidget->toggleViewAction(),