[chronojump] After session/persons grow/shrink ensure treeview scrolls to selected person

[Xavier de Blas <xaviblas src gnome org>]

commit 3398cb5a86f397418898861beeef03b94ff817eb
Author: Xavier de Blas <xaviblas gmail com>
Date:   Fri Jul 23 14:17:26 2021 +0200

    After session/persons grow/shrink ensure treeview scrolls to selected person

 src/gui/app1/menu.cs   | 12 ++++++++++++
 src/treeview/person.cs | 13 +++++++++++++
 2 files changed, 25 insertions(+)
---
diff --git a/src/gui/app1/menu.cs b/src/gui/app1/menu.cs
index 7c98db499..17e1f0231 100644
--- a/src/gui/app1/menu.cs
+++ b/src/gui/app1/menu.cs
@@ -326,6 +326,18 @@ public partial class ChronoJumpWindow
                if(preferences.personPhoto)
                        vbox_persons_bottom.Visible =
                                (! check_menu_session.Active && ! check_manage_persons.Active);
+
+               //scroll it, but wait a bit before to be all the things at place
+               if(myTreeViewPersons != null)
+                       GLib.Timeout.Add(50, new GLib.TimeoutHandler(scrollTreeviewPersons));
+       }
+
+       private bool scrollTreeviewPersons ()
+       {
+               if(myTreeViewPersons != null)           //extra check
+                       myTreeViewPersons.ScrollToSelectedRow ();
+
+               return false;
        }
 
        private void on_button_menu_help_clicked (object o, EventArgs args)
diff --git a/src/treeview/person.cs b/src/treeview/person.cs
index fc821c8f0..e48455499 100644
--- a/src/treeview/person.cs
+++ b/src/treeview/person.cs
@@ -202,6 +202,19 @@ public class TreeViewPersons
                return found;
        }
 
+       //to scroll when elements of gui are resized changed, like the sidebar session/persons shrink
+       public void ScrollToSelectedRow ()
+       {
+               TreeIter iter;
+               Gtk.TreeModel model = treeview.Model;
+
+               if (! treeview.Selection.GetSelected (out model, out iter))
+                       return;
+
+               TreePath path = store.GetPath (iter);
+               treeview.ScrollToCell (path, null, true, 0, 0);
+       }
+
        public void SelectRowByUniqueID(int personID)
        {
                SelectRow(FindRow(personID));