[gnome-builder] gtk: add helper to check if an iter is visible.

[Christian Hergert <chergert src gnome org>]

commit c18aa8a740160ec28c5209cea6c36b942b4e0cb7
Author: Christian Hergert <christian hergert me>
Date:   Wed Dec 31 15:08:11 2014 -0800

    gtk: add helper to check if an iter is visible.

 src/util/gb-gtk.c |   16 ++++++++++++++++
 src/util/gb-gtk.h |    3 +++
 2 files changed, 19 insertions(+), 0 deletions(-)
---
diff --git a/src/util/gb-gtk.c b/src/util/gb-gtk.c
index 3055f39..c6e77b5 100644
--- a/src/util/gb-gtk.c
+++ b/src/util/gb-gtk.c
@@ -138,3 +138,19 @@ gb_gtk_text_view_scroll_to_iter (GtkTextView *text_view,
 
   g_timeout_add (50, gb_gtk_text_view_scroll_to_iter_cb, state);
 }
+
+gboolean
+gb_gtk_text_view_get_iter_visible (GtkTextView *text_view,
+                                   GtkTextIter *iter)
+{
+  GdkRectangle visible_rect;
+  GdkRectangle iter_location;
+
+  g_return_val_if_fail (GTK_IS_TEXT_VIEW (text_view), FALSE);
+  g_return_val_if_fail (iter, FALSE);
+
+  gtk_text_view_get_visible_rect (text_view, &visible_rect);
+  gtk_text_view_get_iter_location (text_view, iter, &iter_location);
+
+  return gdk_rectangle_intersect (&visible_rect, &iter_location, NULL);
+}
diff --git a/src/util/gb-gtk.h b/src/util/gb-gtk.h
index 21e3905..66304c4 100644
--- a/src/util/gb-gtk.h
+++ b/src/util/gb-gtk.h
@@ -35,6 +35,9 @@ void gb_gtk_text_view_scroll_to_iter (GtkTextView *text_view,
                                       gdouble      xalign,
                                       gdouble      yalign);
 
+gboolean gb_gtk_text_view_get_iter_visible (GtkTextView *text_view,
+                                            GtkTextIter *iter);
+
 G_END_DECLS
 
 #endif /* GB_GTK_H */