Gui: Disallow adding props to multiple objects

This commit is in preparation for switching the old Add Property dialog
to the Add Property VarSet dialog.  For now, this dialog does not handle
adding properties for multiple objects.

src/Gui/Tree.cpp

@@ -1512,6 +1512,39 @@ void TreeWidget::setupResizableColumn(TreeWidget *tree) {
     }
 }
 
+std::vector<Document*> TreeWidget::getSelectedDocuments() {
+    std::vector<Document*> ret;
+    TreeWidget* tree = instance();
+    if (!tree || !tree->isSelectionAttached()) {
+        for (auto pTree : Instances)
+            if (pTree->isSelectionAttached()) {
+                tree = pTree;
+                break;
+            }
+    }
+    if (!tree)
+        return ret;
+
+    if (tree->selectTimer->isActive())
+        tree->onSelectTimer();
+    else
+        tree->_updateStatus(false);
+
+    const auto items = tree->selectedItems();
+    for (auto ti : items) {
+        if (ti->type() != DocumentType)
+            continue;
+        auto item = static_cast<DocumentItem*>(ti);
+        auto doc = item->document();
+        if (!doc || !doc->getDocument()) {
+            FC_WARN("skip invalid document");
+            continue;
+        }
+        ret.push_back(doc);
+    }
+    return ret;
+}
+
 std::vector<TreeWidget::SelInfo> TreeWidget::getSelection(App::Document* doc)
 {
     std::vector<SelInfo> ret;

src/Gui/Tree.h

@@ -92,6 +92,7 @@ public:
      * which Gui::Selection() cannot provide.
      */
     static std::vector<SelInfo> getSelection(App::Document *doc=nullptr);
+    static std::vector<Document*> getSelectedDocuments();
 
     static TreeWidget *instance();
 

src/Gui/propertyeditor/PropertyEditor.cpp

@@ -40,6 +40,8 @@
 #include <Base/Console.h>
 #include <Base/Tools.h>
 
+#include "Document.h"
+#include "Tree.h"
 #include "PropertyEditor.h"
 #include "Dialogs/DlgAddProperty.h"
 #include "MainWindow.h"
@@ -775,6 +777,19 @@ enum MenuAction
     MA_Copy,
 };
 
+static App::PropertyContainer* getSelectedPropertyContainer()
+{
+    auto sels = Gui::Selection().getSelection("*");
+    if (sels.size() == 1) {
+        return sels[0].pObject;
+    }
+    std::vector<Gui::Document*> docs = Gui::TreeWidget::getSelectedDocuments();
+    if (docs.size() == 1) {
+        return docs[0]->getDocument();
+    }
+    return nullptr;
+}
+
 std::unordered_set<App::Property*> PropertyEditor::acquireSelectedProperties() const
 {
     std::unordered_set<App::Property*> props;
@@ -831,7 +846,11 @@ void PropertyEditor::contextMenuEvent(QContextMenuEvent*)
     }
 
     // add property
-    menu.addAction(tr("Add Property"))->setData(QVariant(MA_AddProp));
+    if (getSelectedPropertyContainer()) {
+        menu.addAction(tr("Add Property"))->setData(QVariant(MA_AddProp));
+    }
+
+    // rename property group
     if (!props.empty() && std::all_of(props.begin(), props.end(), [](auto prop) {
             return prop->testStatus(App::Property::PropDynamic)
                 && !boost::starts_with(prop->getName(), prop->getGroup());
@@ -989,18 +1008,12 @@ void PropertyEditor::contextMenuEvent(QContextMenuEvent*)
             }
             break;
         case MA_AddProp: {
+            App::PropertyContainer* container = getSelectedPropertyContainer();
+            if (container == nullptr) {
+                return;
+            }
             App::AutoTransaction committer("Add property");
-            std::unordered_set<App::PropertyContainer*> containers;
-            auto sels = Gui::Selection().getSelection("*");
-            if (sels.size() == 1) {
-                containers.insert(sels[0].pObject);
-            }
-            else {
-                for (auto prop : props) {
-                    containers.insert(prop->getContainer());
-                }
-            }
-            Gui::Dialog::DlgAddProperty dlg(Gui::getMainWindow(), std::move(containers));
+            Gui::Dialog::DlgAddProperty dlg(Gui::getMainWindow(), container);
             dlg.exec();
             return;
         }