[gparted] port-to-gtk3: Use Gtk::CellLayout::get_cells() (#7)

[Mike Fleetwood <mfleetwo src gnome org>]

commit 202e6e90345d83d0f53455e5a1e41e03c94a8abd
Author: Luca Bacci <luca bacci982 gmail com>
Date:   Fri Aug 3 20:24:25 2018 +0200

    port-to-gtk3: Use Gtk::CellLayout::get_cells() (#7)
    
    GParted uses Gtk::TreeViewColumn::get_cell_renderers().  This is not
    present in Gtkmm3.  Now Gtk::TreeViewColumn inherits from
    Gtk::CellLayout and we have to use Gtk::CellLayout::get_cells() instead.
    
    GtkCellLayout was introduced in Gtk2 version 2.18 as the common
    interface for containers of cell renderers.
    
    The C++ wrapper Gtk::CellLayout was introduced in Gtkmm2 version 2.18,
    but Gtk::TreeViewColumn was never made to inherit from Gtk::CellLayout
    to avoid breaking the API / ABI.  That change was made for Gtkmm3.
    
    This is an excerpt from gtkmm/treeviewcolumn.h header in Gtkmm2:
      // TODO: Should be deprecated, but we cannot derive from CellLayout
      // without breaking API and ABI.
    
      /** Returns a list of all the cell renderers in the column,
       * in no particular order.
       *
       * @return A list of Gtk::CellRenderers.
       */
      Glib::ListHandle<CellRenderer*> get_cell_renderers();
    
    Replace Gtk::TreeViewColumn::get_cell_renderers() with base class
    method Gtk::CellLayout::get_cells().
    
    Reference:
    
    [1] Commit - "Deprecate get_cell_renderers implementations"
        https://gitlab.gnome.org/GNOME/gtk/commit/6abc52a29d2b15c255ada7d199b703a95f8c565b
    
    Closes #7 - Port to Gtk3

 src/TreeView_Detail.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/TreeView_Detail.cc b/src/TreeView_Detail.cc
index 03a8ec3b..2e105b03 100644
--- a/src/TreeView_Detail.cc
+++ b/src/TreeView_Detail.cc
@@ -60,7 +60,7 @@ TreeView_Detail::TreeView_Detail()
        // Color pixbuf cell is left aligned.
        get_column(2)->get_first_cell()->property_xalign() = Gtk::ALIGN_START;
        // File system text cell is left aligned.
-       std::vector<Gtk::CellRenderer*> renderers = get_column( 2 )->get_cell_renderers();
+       std::vector<Gtk::CellRenderer *> renderers = get_column(2)->get_cells();
        Gtk::CellRendererText *cell_renderer_text = dynamic_cast<Gtk::CellRendererText*>( renderers.back() );
        cell_renderer_text->property_xalign() = Gtk::ALIGN_START;