clutter-text: prevent text buffer creation if not needed

When allocating or asking for preferred width/height on a ClutterText,
it can notify a change on buffer/text/max-length if no text has been
set.

https://bugzilla.gnome.org/show_bug.cgi?id=703882
(cherry picked from commit eed94960562693e489354afb2a78a355301515fa)
Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/clutter/clutter-text.c b/clutter/clutter-text.c
index 0cfb63f69..b5d1198d7 100644
--- a/clutter/clutter-text.c
+++ b/clutter/clutter-text.c
@@ -341,6 +341,18 @@ clutter_text_clear_selection (ClutterText *self)
     }
 }
 
+static gboolean
+clutter_text_is_empty (ClutterText *self)
+{
+  if (self->priv->buffer == NULL)
+    return TRUE;
+
+  if (clutter_text_buffer_get_length (self->priv->buffer) == 0)
+    return TRUE;
+
+  return FALSE;
+}
+
 static gchar *
 clutter_text_get_display_text (ClutterText *self)
 {
@@ -348,6 +360,13 @@ clutter_text_get_display_text (ClutterText *self)
   ClutterTextBuffer *buffer;
   const gchar *text;
 
+  /* short-circuit the case where the buffer is unset or it's empty,
+   * to avoid creating a pointless TextBuffer and emitting
+   * notifications with it
+   */
+  if (clutter_text_is_empty (self))
+    return g_strdup ("");
+
   buffer = get_buffer (self);
   text = clutter_text_buffer_get_text (buffer);