scrolledwindow: Resolve whether we use overlay scrollbars early.

Widgets should support size requests before being realized in general,
otherwise this can cause flicker/resize at initial display time as
the toplevel window can make a request before realize/allocate.

This also makes the added testsuite/gtk/scrolledwindow.c test work again,
this was broken because we only ever calculate whether we are going
to use overlay scrollbars once the scrolled window is realized (and
the test case does not realize any window).

diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index a3a89b61e590f4275ac3d85b2469cb643205a48a..7d149aee36cc1d3d52fca6bf8a3757261f36ee33 100644 (file)
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -400,6 +400,7 @@ static gboolean _gtk_scrolled_window_get_overshoot (GtkScrolledWindow *scrolled_
 static void     gtk_scrolled_window_start_deceleration (GtkScrolledWindow *scrolled_window);
 static gint     _gtk_scrolled_window_get_scrollbar_spacing (GtkScrolledWindow *scrolled_window);
 
+static void     gtk_scrolled_window_update_use_indicators (GtkScrolledWindow *scrolled_window);
 static void     remove_indicator     (GtkScrolledWindow *sw,
                                       Indicator         *indicator);
 static void     indicator_stop_fade  (Indicator         *indicator);
@@ -2146,6 +2147,8 @@ gtk_scrolled_window_init (GtkScrolledWindow *scrolled_window)
       gtk_css_node_set_state (priv->undershoot_node[i], gtk_css_node_get_state (widget_node));
       g_object_unref (priv->undershoot_node[i]);
     }
+
+  gtk_scrolled_window_update_use_indicators (scrolled_window);
 }
 
 /**
@@ -4316,6 +4319,23 @@ remove_indicator (GtkScrolledWindow *scrolled_window,
   indicator->current_pos = 1.0;
 }
 
+static void
+gtk_scrolled_window_sync_use_indicators (GtkScrolledWindow *scrolled_window)
+{
+  GtkScrolledWindowPrivate *priv = scrolled_window->priv;
+
+  if (priv->use_indicators)
+    {
+      setup_indicator (scrolled_window, &priv->hindicator, priv->hscrollbar);
+      setup_indicator (scrolled_window, &priv->vindicator, priv->vscrollbar);
+    }
+  else
+    {
+      remove_indicator (scrolled_window, &priv->hindicator);
+      remove_indicator (scrolled_window, &priv->vindicator);
+    }
+}
+
 static void
 gtk_scrolled_window_update_use_indicators (GtkScrolledWindow *scrolled_window)
 {
@@ -4331,16 +4351,8 @@ gtk_scrolled_window_update_use_indicators (GtkScrolledWindow *scrolled_window)
     {
       priv->use_indicators = use_indicators;
 
-      if (priv->use_indicators)
-        {
-          setup_indicator (scrolled_window, &priv->hindicator, priv->hscrollbar);
-          setup_indicator (scrolled_window, &priv->vindicator, priv->vscrollbar);
-        }
-      else
-        {
-          remove_indicator (scrolled_window, &priv->hindicator);
-          remove_indicator (scrolled_window, &priv->vindicator);
-        }
+      if (gtk_widget_get_realized (GTK_WIDGET (scrolled_window)))
+        gtk_scrolled_window_sync_use_indicators (scrolled_window);
 
       gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
     }
@@ -4383,7 +4395,7 @@ gtk_scrolled_window_realize (GtkWidget *widget)
   priv->hindicator.scrollbar = priv->hscrollbar;
   priv->vindicator.scrollbar = priv->vscrollbar;
 
-  gtk_scrolled_window_update_use_indicators (scrolled_window);
+  gtk_scrolled_window_sync_use_indicators (scrolled_window);
 }
 
 static void
@@ -4587,8 +4599,7 @@ gtk_scrolled_window_set_overlay_scrolling (GtkScrolledWindow *scrolled_window,
     {
       priv->overlay_scrolling = overlay_scrolling;
 
-      if (gtk_widget_get_realized (GTK_WIDGET (scrolled_window)))
-        gtk_scrolled_window_update_use_indicators (scrolled_window);
+      gtk_scrolled_window_update_use_indicators (scrolled_window);
 
       g_object_notify_by_pspec (G_OBJECT (scrolled_window), properties[PROP_OVERLAY_SCROLLING]);
     }