[gitg] Restore history selection on relaod

[Jesse van den Kieboom <jessevdk src gnome org>]

commit 6f6807cbbd73549ae6e4d93335ba7a898e80542b
Author: Jesse van den Kieboom <jessevdk gnome org>
Date:   Thu Jul 10 22:17:44 2014 +0200

    Restore history selection on relaod
    
    https://bugzilla.gnome.org/show_bug.cgi?id=702686

 gitg/history/gitg-history.vala |   55 +++++++++++++++++++++++++++++++++++++--
 1 files changed, 52 insertions(+), 3 deletions(-)
---
diff --git a/gitg/history/gitg-history.vala b/gitg/history/gitg-history.vala
index 779773a..2e2b2ab 100644
--- a/gitg/history/gitg-history.vala
+++ b/gitg/history/gitg-history.vala
@@ -32,6 +32,8 @@ namespace GitgHistory
                private Navigation? d_navigation_model;
                private Gitg.CommitModel? d_commit_list_model;
                private Gee.HashSet<Ggit.OId> d_selected;
+               private Ggit.OId? d_scroll_to;
+               private float d_scroll_y;
                private ulong d_insertsig;
                private Settings d_settings;
 
@@ -142,6 +144,17 @@ namespace GitgHistory
                        if (d_selected.size == 0 || d_selected.remove(commit.get_id()))
                        {
                                d_main.commit_list_view.get_selection().select_path(path);
+
+                               if (commit.get_id().equal(d_scroll_to))
+                               {
+                                       d_main.commit_list_view.scroll_to_cell(path,
+                                                                              null,
+                                                                              true,
+                                                                              d_scroll_y,
+                                                                              0);
+
+                                       d_scroll_to = null;
+                               }
                        }
 
                        if (d_selected.size == 0)
@@ -221,9 +234,48 @@ namespace GitgHistory
 
                private void reload()
                {
+                       var view = d_main.commit_list_view;
+
                        double vadj = d_main.navigation_view.get_vadjustment().get_value();
 
+                       d_selected.clear();
 
+                       Gtk.TreePath startp, endp;
+                       view.get_visible_range(out startp, out endp);
+
+                       d_scroll_to = null;
+
+                       view.get_selection().selected_foreach((model, path, iter) => {
+                               var c = d_commit_list_model.commit_from_iter(iter);
+
+                               if (c != null)
+                               {
+                                       d_selected.add(c.get_id());
+
+                                       if (d_scroll_to == null &&
+                                           startp.compare(path) <= 0 && endp.compare(path) >= 0)
+                                       {
+                                               Gdk.Rectangle rect;
+                                               Gdk.Rectangle visrect;
+
+                                               view.get_cell_area(path, null, out rect);
+                                               view.get_visible_rect(out visrect);
+
+                                               int x, y;
+
+                                               view.convert_tree_to_bin_window_coords(visrect.x,
+                                                                                      visrect.y,
+                                                                                      out x,
+                                                                                      out y);
+
+                                               // + 2 seems to work correctly here, but this is probably
+                                               // something related to a border or padding of the
+                                               // treeview (i.e. theme related)
+                                               d_scroll_y = (float)(rect.y + rect.height / 2.0 - y + 2) / 
(float)visrect.height;
+                                               d_scroll_to = c.get_id();
+                                       }
+                               }
+                       });
 
                        // Clears the commit model
                        d_commit_list_model.repository = repository;
@@ -290,11 +342,8 @@ namespace GitgHistory
                                }
                        }
 
-                       d_selected.clear();
-
                        if (id != null)
                        {
-                               d_selected.add(id);
                                d_commit_list_model.set_include(new Ggit.OId[] { id });
                        }
                        else