[gimp] Add comment why we implement focus_in_event() and focus_out_event()

[Michael Natterer <mitch src gnome org>]

commit 6a00a4ef223ddfde7082e7862621fb07ceacf8e5
Author: Michael Natterer <mitch gimp org>
Date:   Wed Nov 4 19:32:13 2009 +0100

    Add comment why we implement focus_in_event() and focus_out_event()

 app/display/gimpcanvas.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/app/display/gimpcanvas.c b/app/display/gimpcanvas.c
index ce5749d..3f65b5e 100644
--- a/app/display/gimpcanvas.c
+++ b/app/display/gimpcanvas.c
@@ -299,6 +299,9 @@ static gboolean
 gimp_canvas_focus_in_event (GtkWidget     *widget,
                             GdkEventFocus *event)
 {
+  /*  don't allow the default impl to invalidate the whole widget,
+   *  we don't draw a focus indicator anyway.
+   */
   return FALSE;
 }
 
@@ -306,6 +309,8 @@ static gboolean
 gimp_canvas_focus_out_event (GtkWidget     *widget,
                              GdkEventFocus *event)
 {
+  /*  see focus-in-event
+   */
   return FALSE;
 }