[gtk+/wip/overlay-scrollbar] Fix repeated mode changes

[Matthias Clasen <matthiasc src gnome org>]

commit 6529ded2fc8db69c7263ea81550b80a74c9f8e05
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Oct 9 17:02:51 2014 -0400

    Fix repeated mode changes
    
    Make sure to properly undo and redo all the setup
    work in setup_indicator and remove_indicator so they
    can be used repeatedly.

 gtk/gtkscrolledwindow.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index e6affa2..930cbdb 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -3474,7 +3474,13 @@ setup_indicator (GtkScrolledWindow *scrolled_window,
 
   indicator->enabled = TRUE;
   indicator->scrollbar = scrollbar;
+
+  g_object_ref (scrollbar);
+  gtk_widget_unparent (scrollbar);
   gtk_widget_set_parent_window (scrollbar, indicator->window);
+  gtk_widget_set_parent (scrollbar, GTK_WIDGET (scrolled_window));
+  g_object_unref (scrollbar);
+
   gtk_style_context_add_class (context, "overlay-indicator");
   g_signal_connect (context, "changed",
                     G_CALLBACK (indicator_style_changed), indicator);
@@ -3484,6 +3490,10 @@ setup_indicator (GtkScrolledWindow *scrolled_window,
                     G_CALLBACK (indicator_leave_notify), indicator);
   g_signal_connect (adjustment, "value-changed",
                     G_CALLBACK (indicator_value_changed), indicator);
+
+  gdk_window_hide (indicator->window);
+  gtk_widget_set_opacity (scrollbar, 0.0);
+  indicator->current_pos = 0.0;
 }
 
 static void
@@ -3527,7 +3537,9 @@ remove_indicator (GtkScrolledWindow *scrolled_window,
   gtk_widget_set_parent (scrollbar, GTK_WIDGET (scrolled_window));
   g_object_unref (scrollbar);
 
+  gdk_window_show (indicator->window);
   gtk_widget_set_opacity (scrollbar, 1.0);
+  indicator->current_pos = 1.0;
 }
 
 static gboolean
@@ -3801,6 +3813,7 @@ gtk_scrolled_window_set_overlay_scrolling (GtkScrolledWindow *scrolled_window,
   if (priv->overlay_scrolling != overlay_scrolling)
     {
       priv->overlay_scrolling = overlay_scrolling;
+
       if (gtk_widget_get_realized (GTK_WIDGET (scrolled_window)))
         gtk_scrolled_window_update_touch_mode (scrolled_window);