[gtk] tooltip: Use gtk_widget_compute_bounds to get tootip widget anchor

[Timm Bäder <baedert src gnome org>]

commit 47ba423eca27be751a8fb9a3ad2f73fb483b67e6
Author: Timm Bäder <mail baedert org>
Date:   Sun Feb 3 06:47:57 2019 +0100

    tooltip: Use gtk_widget_compute_bounds to get tootip widget anchor
    
    Instead of using gtk_widget_get_allocated_width/height, which might
    return the wrong box for the tooltip widget.

 gtk/gtktooltip.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
---
diff --git a/gtk/gtktooltip.c b/gtk/gtktooltip.c
index 07f535ada5..2b9e6c0a2e 100644
--- a/gtk/gtktooltip.c
+++ b/gtk/gtktooltip.c
@@ -570,6 +570,7 @@ gtk_tooltip_position (GtkTooltip *tooltip,
                       GdkDevice  *device)
 {
   GtkSettings *settings;
+  graphene_rect_t anchor_bounds;
   GdkRectangle anchor_rect;
   GdkSurface *surface;
   GdkSurface *effective_toplevel;
@@ -584,12 +585,11 @@ gtk_tooltip_position (GtkTooltip *tooltip,
   tooltip->tooltip_widget = new_tooltip_widget;
 
   toplevel = _gtk_widget_get_toplevel (new_tooltip_widget);
-  gtk_widget_translate_coordinates (new_tooltip_widget, toplevel,
-                                    0, 0,
-                                    &anchor_rect.x, &anchor_rect.y);
-
-  anchor_rect.width = gtk_widget_get_allocated_width (new_tooltip_widget);
-  anchor_rect.height = gtk_widget_get_allocated_height (new_tooltip_widget);
+  gtk_widget_compute_bounds (new_tooltip_widget, toplevel, &anchor_bounds);
+  anchor_rect = (GdkRectangle) {
+    floorf (anchor_bounds.origin.x), floorf (anchor_bounds.origin.y),
+    ceilf (anchor_bounds.size.width), ceilf (anchor_bounds.size.height)
+  };
 
   settings = gtk_settings_get_for_display (display);
   g_object_get (settings,