From a763546c8f155aa08cf79575e4069f058a7c6bce Mon Sep 17 00:00:00 2001
From: Kristian Rietveld <kris@gtk.org>
Date: Mon, 21 Dec 2009 22:33:59 +0100
Subject: [PATCH] Correct problems with earlier fix for bug #480065

Initialize event_last_[xy] to out of range coordinates and also update
these values in enter and leave notify.  Fix up calls to
update_prelight() from size allocate.  Unconditionally doing these calls
caused problems with hover selection.  Now we only do this call when
the "width before the expander column" has changed.  (Which might be
awkward, but it is the best heuristic I could come up with so far).
---
 gtk/gtktreeprivate.h |  2 ++
 gtk/gtktreeview.c    | 80 +++++++++++++++++++++++++++++++++++---------
 2 files changed, 67 insertions(+), 15 deletions(-)

diff --git a/gtk/gtktreeprivate.h b/gtk/gtktreeprivate.h
index 43c6e31069..8a84e89cdb 100644
--- a/gtk/gtktreeprivate.h
+++ b/gtk/gtktreeprivate.h
@@ -177,6 +177,8 @@ struct _GtkTreeViewPrivate
   GList *column_drag_info;
   GtkTreeViewColumnReorder *cur_reorder;
 
+  gint prev_width_before_expander;
+
   /* Interactive Header reordering */
   GdkWindow *drag_window;
   GdkWindow *drag_highlight_window;
diff --git a/gtk/gtktreeview.c b/gtk/gtktreeview.c
index ef4cb46742..4be8f9e742 100644
--- a/gtk/gtktreeview.c
+++ b/gtk/gtktreeview.c
@@ -1382,6 +1382,9 @@ gtk_tree_view_init (GtkTreeView *tree_view)
 
   tree_view->priv->last_button_x = -1;
   tree_view->priv->last_button_y = -1;
+
+  tree_view->priv->event_last_x = -10000;
+  tree_view->priv->event_last_y = -10000;
 }
 
 
@@ -2056,6 +2059,25 @@ gtk_tree_view_size_request (GtkWidget      *widget,
     }
 }
 
+static int
+gtk_tree_view_calculate_width_before_expander (GtkTreeView *tree_view)
+{
+  int width = 0;
+  GList *list;
+  gboolean rtl;
+
+  rtl = (gtk_widget_get_direction (GTK_WIDGET (tree_view)) == GTK_TEXT_DIR_RTL);
+  for (list = (rtl ? g_list_last (tree_view->priv->columns) : g_list_first (tree_view->priv->columns));
+       list->data != tree_view->priv->expander_column;
+       list = (rtl ? list->prev : list->next))
+    {
+      GtkTreeViewColumn *column = list->data;
+
+      width += column->width;
+    }
+
+  return width;
+}
 
 static void
 invalidate_column (GtkTreeView       *tree_view,
@@ -2473,14 +2495,30 @@ gtk_tree_view_size_allocate (GtkWidget     *widget,
 	    }
 	}
 
+      if (width_changed && tree_view->priv->expander_column)
+        {
+          /* Might seem awkward, but is the best heuristic I could come up
+           * with.  Only if the width of the columns before the expander
+           * changes, we will update the prelight status.  It is this
+           * width that makes the expander move vertically.  Always updating
+           * prelight status causes trouble with hover selections.
+           */
+          gint width_before_expander;
+
+          width_before_expander = gtk_tree_view_calculate_width_before_expander (tree_view);
+
+          if (tree_view->priv->prev_width_before_expander
+              != width_before_expander)
+              update_prelight (tree_view,
+                               -tree_view->priv->event_last_x,
+                               -tree_view->priv->event_last_y);
+
+          tree_view->priv->prev_width_before_expander = width_before_expander;
+        }
+
       /* This little hack only works if we have an LTR locale, and no column has the  */
       if (width_changed)
 	{
-          if (tree_view->priv->tree)
-            update_prelight (tree_view,
-                             tree_view->priv->event_last_x,
-                             tree_view->priv->event_last_y);
-
 	  if (gtk_widget_get_direction (GTK_WIDGET (tree_view)) == GTK_TEXT_DIR_LTR &&
 	      ! has_expand_column)
 	    invalidate_last_column (tree_view);
@@ -3299,6 +3337,16 @@ prelight_or_select (GtkTreeView *tree_view,
     do_prelight (tree_view, tree, node, x, y);
 }
 
+static void
+ensure_unprelighted (GtkTreeView *tree_view)
+{
+  do_prelight (tree_view,
+	       NULL, NULL,
+	       -1000, -1000); /* coords not possibly over an arrow */
+
+  g_assert (tree_view->priv->prelight_node == NULL);
+}
+
 static void
 update_prelight (GtkTreeView *tree_view,
                  gint         x,
@@ -3308,6 +3356,12 @@ update_prelight (GtkTreeView *tree_view,
   GtkRBTree *tree;
   GtkRBNode *node;
 
+  if (x == -10000)
+    {
+      ensure_unprelighted (tree_view);
+      return;
+    }
+
   new_y = TREE_WINDOW_Y_TO_RBTREE_Y (tree_view, y);
   if (new_y < 0)
     new_y = 0;
@@ -3319,16 +3373,6 @@ update_prelight (GtkTreeView *tree_view,
     prelight_or_select (tree_view, tree, node, x, y);
 }
 
-static void
-ensure_unprelighted (GtkTreeView *tree_view)
-{
-  do_prelight (tree_view,
-	       NULL, NULL,
-	       -1000, -1000); /* coords not possibly over an arrow */
-
-  g_assert (tree_view->priv->prelight_node == NULL);
-}
-
 
 
 
@@ -5542,6 +5586,9 @@ gtk_tree_view_enter_notify (GtkWidget        *widget,
     new_y = 0;
   _gtk_rbtree_find_offset (tree_view->priv->tree, new_y, &tree, &node);
 
+  tree_view->priv->event_last_x = event->x;
+  tree_view->priv->event_last_y = event->y;
+
   if ((tree_view->priv->button_pressed_node == NULL) ||
       (tree_view->priv->button_pressed_node == node))
     prelight_or_select (tree_view, tree, node, event->x, event->y);
@@ -5566,6 +5613,9 @@ gtk_tree_view_leave_notify (GtkWidget        *widget,
                                    tree_view->priv->prelight_node,
                                    NULL);
 
+  tree_view->priv->event_last_x = -10000;
+  tree_view->priv->event_last_y = -10000;
+
   prelight_or_select (tree_view,
 		      NULL, NULL,
 		      -1000, -1000); /* coords not possibly over an arrow */
-- 
2.30.2