tdf#130857 qt weld: Evaluate GtkTreeView:show-expanders property

Evaluate the GtkTreeView:show-expanders property [1]
and set the QTreeView::rootIsDecorated propert accordingly [2]:

> This property holds whether to show controls for expanding and
> collapsing top-level items
>
> Items with children are typically shown with controls to expand and
> collapse them, allowing their children to be shown or hidden. If this
> property is false, these controls are not shown for top-level items.
> This can be used to make a single level tree structure appear like a
> simple list of items.

With this in place, there are no more expanders shown for
Calc's "Sheets" -> "Show Sheet" dialog for the native Qt
version, just like with the gtk3 or gen versions.

[1] https://docs.gtk.org/gtk3/property.TreeView.show-expanders.html
[2] https://doc.qt.io/qt-6/qtreeview.html#rootIsDecorated-prop

Change-Id: I11bcdd39695d230866abddf6d4b305dd6af52f59
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/177548
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

1 files changed, 12 insertions, 0 deletions

diff --git a/vcl/source/window/builder.cxx b/vcl/source/window/builder.cxx
index 6cdce48f5cbd..e638eaa21854 100644
--- a/vcl/source/window/builder.cxx
+++ b/vcl/source/window/builder.cxx
@@ -3535,6 +3535,18 @@ bool BuilderBase::extractResizable(stringmap& rMap)
     return bResizable;
 }
 
+bool BuilderBase::extractShowExpanders(VclBuilder::stringmap& rMap)
+{
+    bool bShowExpanders = true;
+    VclBuilder::stringmap::iterator aFind = rMap.find(u"show-expanders"_ustr);
+    if (aFind != rMap.end())
+    {
+        bShowExpanders = toBool(aFind->second);
+        rMap.erase(aFind);
+    }
+    return bShowExpanders;
+}
+
 OUString BuilderBase::extractTooltipText(stringmap& rMap)
 {
     OUString sTooltipText;