Add functions provided by the midend to tell a front end whether GUI

buttons for undo and redo should currently be greyed out.

[originally from svn r9139]

1 files changed, 10 insertions, 0 deletions

diff --git a/midend.c b/midend.c
index 05ea663..300e2bf 100644
--- a/midend.c
+++ b/midend.c
@@ -428,6 +428,16 @@ void midend_new_game(midend *me)
     me->pressed_mouse_button = 0;
 }
 
+int midend_can_undo(midend *me)
+{
+    return (me->statepos > 1);
+}
+
+int midend_can_redo(midend *me)
+{
+    return (me->statepos < me->nstates);
+}
+
 static int midend_undo(midend *me)
 {
     if (me->statepos > 1) {