set the prev button in accordance to if it is possible to go back or not

1 files changed, 10 insertions, 0 deletions

diff --git a/dispatch.py b/dispatch.py
index 505c56a63..6499f0824 100644
--- a/dispatch.py
+++ b/dispatch.py
@@ -109,6 +109,16 @@ class Dispatcher:
 	self.dir = 1
 	self.moveStep()
 
+    def canGoBack(self):
+        # begin with the step before this one.  If all steps are skipped,
+        # we can not go backwards from this screen
+        i = self.step - 1
+        while i >= self.firstStep:
+            if not self.skipSteps.has_key(installSteps[i][0]):
+                return 1
+            i = i - 1
+        return 0
+
     def setStepList(self, *steps):
         # only remove non-permanently skipped steps from our skip list
         for step, state in self.skipSteps.items():