QmlDesigner: Hide dynamic properties if multiple items are selected

If multiple items get selected it is not clear to which item
the property belongs. Therefore we hide the section.

Task-number: QDS-7688
Change-Id: Ieaa0114d87974fea3135adc2d1bcd979c2236ed2
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

share/qtcreator/qmldesigner/propertyEditorQmlSources/QtQuick/ItemPane.qml

@@ -39,6 +39,7 @@ PropertyEditorPane {
 
     DynamicPropertiesSection {
         propertiesModel: SelectionDynamicPropertiesModel {}
+        visible: !hasMultiSelection
     }
 
     GeometrySection {}

share/qtcreator/qmldesigner/propertyEditorQmlSources/QtQuick3D/Object3DPane.qml

@@ -42,6 +42,7 @@ PropertyEditorPane {
 
         DynamicPropertiesSection {
             propertiesModel: SelectionDynamicPropertiesModel {}
+            visible: !hasMultiSelection
         }
 
         Loader {

src/plugins/qmldesigner/components/propertyeditor/propertyeditorcontextobject.cpp

@@ -429,6 +429,20 @@ QQmlComponent *PropertyEditorContextObject::specificQmlComponent()
     return m_qmlComponent;
 }
 
+bool PropertyEditorContextObject::hasMultiSelection() const
+{
+    return m_hasMultiSelection;
+}
+
+void PropertyEditorContextObject::setHasMultiSelection(bool b)
+{
+    if (b == m_hasMultiSelection)
+        return;
+
+    m_hasMultiSelection = b;
+    emit hasMultiSelectionChanged();
+}
+
 void PropertyEditorContextObject::setSpecificsUrl(const QUrl &newSpecificsUrl)
 {
     if (newSpecificsUrl == m_specificsUrl)

src/plugins/qmldesigner/components/propertyeditor/propertyeditorcontextobject.h

@@ -68,6 +68,9 @@ class PropertyEditorContextObject : public QObject
 
     Q_PROPERTY(QQmlComponent* specificQmlComponent READ specificQmlComponent NOTIFY specificQmlComponentChanged)
 
+    Q_PROPERTY(bool hasMultiSelection READ hasMultiSelection WRITE setHasMultiSelection NOTIFY
+                   hasMultiSelectionChanged)
+
 public:
     PropertyEditorContextObject(QObject *parent = nullptr);
 
@@ -126,6 +129,10 @@ public:
 
     bool hasAliasExport() const { return m_aliasExport; }
 
+    bool hasMultiSelection() const;
+
+    void setHasMultiSelection(bool);
+
 signals:
     void specificsUrlChanged();
     void specificQmlDataChanged();
@@ -142,6 +149,7 @@ signals:
     void hasAliasExportChanged();
     void hasActiveTimelineChanged();
     void activeDragSuffixChanged();
+    void hasMultiSelectionChanged();
 
 public slots:
 
@@ -192,6 +200,8 @@ private:
     bool m_setHasActiveTimeline = false;
 
     QString m_activeDragSuffix;
+
+    bool m_hasMultiSelection = false;
 };
 
 class EasingCurveEditor : public QObject