tdf#130857 weld: Filter dummy entries in base weld::TreeView::iter_children

Make the so far purely virtual weld::TreeView::iter_children
a new method implemented directly in the base class that
wraps the new purely virtual weld::TreeView::do_iter_children.

Let the new base class implementation/wrapper detect
when a node is a children-on-demand-node (as described
in the "expanding on-demand node details" comment
above weld::TreeView::get_row_expanded) and return
false right there, to unify and deduplicate the toolkit-specific
implementations a bit.

This is also one step to prepare for implementing support for
on-demand children in the Qt implementation.

Change-Id: I9c0d5e5893ebef029c0065b45b0805d009b99516
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/196994
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

include/vcl/weld/TreeView.hxx

@@ -132,6 +132,7 @@ protected:
     using weld::ItemView::do_set_cursor;
     virtual void do_set_cursor(int pos) = 0;
     virtual void do_scroll_to_row(const TreeIter& rIter) = 0;
+    virtual bool do_iter_children(TreeIter& rIter) const = 0;
     virtual void do_set_children_on_demand(const TreeIter& rIter, bool bChildrenOnDemand) = 0;
     virtual void do_remove_selection() = 0;
 
@@ -318,7 +319,7 @@ public:
     // set iter to point to previous node, sibling first then depth
     virtual bool iter_previous(TreeIter& rIter) const = 0;
     // set iter to point to first child node
-    virtual bool iter_children(TreeIter& rIter) const = 0;
+    bool iter_children(TreeIter& rIter) const;
     bool iter_nth_sibling(TreeIter& rIter, int nChild) const
     {
         bool bRet = true;

vcl/inc/qt5/QtInstanceTreeView.hxx

@@ -64,7 +64,7 @@ public:
     virtual bool iter_previous_sibling(weld::TreeIter& rIter) const override;
     virtual bool iter_next(weld::TreeIter& rIter) const override;
     virtual bool iter_previous(weld::TreeIter& rIter) const override;
-    virtual bool iter_children(weld::TreeIter& rIter) const override;
+    virtual bool do_iter_children(weld::TreeIter& rIter) const override;
     virtual bool iter_parent(weld::TreeIter& rIter) const override;
     virtual int get_iter_depth(const weld::TreeIter& rIter) const override;
 

vcl/inc/salvtables.hxx

@@ -1732,7 +1732,7 @@ public:
 
     virtual bool iter_previous(weld::TreeIter& rIter) const override;
 
-    virtual bool iter_children(weld::TreeIter& rIter) const override;
+    virtual bool do_iter_children(weld::TreeIter& rIter) const override;
 
     virtual bool iter_parent(weld::TreeIter& rIter) const override;
 

vcl/qt5/QtInstanceTreeView.cxx

@@ -233,7 +233,7 @@ bool QtInstanceTreeView::iter_previous(weld::TreeIter&) const
     return false;
 }
 
-bool QtInstanceTreeView::iter_children(weld::TreeIter& rIter) const
+bool QtInstanceTreeView::do_iter_children(weld::TreeIter& rIter) const
 {
     QtInstanceTreeIter& rQtIter = static_cast<QtInstanceTreeIter&>(rIter);
     const QModelIndex aChildIndex = m_pModel->index(0, 0, rQtIter.modelIndex());

vcl/source/app/salvtables.cxx

@@ -4513,17 +4513,11 @@ bool SalInstanceTreeView::iter_previous(weld::TreeIter& rIter) const
     return rVclIter.iter != nullptr;
 }
 
-bool SalInstanceTreeView::iter_children(weld::TreeIter& rIter) const
+bool SalInstanceTreeView::do_iter_children(weld::TreeIter& rIter) const
 {
     SalInstanceTreeIter& rVclIter = static_cast<SalInstanceTreeIter&>(rIter);
     rVclIter.iter = m_xTreeView->FirstChild(rVclIter.iter);
-    bool bRet = rVclIter.iter != nullptr;
-    if (bRet)
-    {
-        //on-demand dummy entry doesn't count
-        return !IsDummyEntry(rVclIter.iter);
-    }
-    return bRet;
+    return rVclIter.iter != nullptr;
 }
 
 bool SalInstanceTreeView::iter_parent(weld::TreeIter& rIter) const

vcl/source/weld/TreeView.cxx

@@ -127,6 +127,14 @@ bool weld::TreeView::is_selected(int pos) const
     return false;
 }
 
+bool weld::TreeView::iter_children(TreeIter& rIter) const
+{
+    if (get_children_on_demand(rIter))
+        return false;
+
+    return do_iter_children(rIter);
+}
+
 bool weld::TreeView::iter_has_child(const TreeIter& rIter) const
 {
     std::unique_ptr<weld::TreeIter> pIter = make_iterator(&rIter);

vcl/unx/gtk3/gtkinst.cxx

@@ -15669,17 +15669,12 @@ public:
         return false;
     }
 
-    virtual bool iter_children(weld::TreeIter& rIter) const override
+    virtual bool do_iter_children(weld::TreeIter& rIter) const override
     {
         GtkInstanceTreeIter& rGtkIter = static_cast<GtkInstanceTreeIter&>(rIter);
         GtkTreeIter tmp;
         bool ret = gtk_tree_model_iter_children(m_pTreeModel, &tmp, &rGtkIter.iter);
         rGtkIter.iter = tmp;
-        if (ret)
-        {
-            //on-demand dummy entry doesn't count
-            return get_text(rGtkIter, -1) != "<dummy>";
-        }
         return ret;
     }