uitests: Add check_in_loop helper function

tests/uitests/newvm.py

@@ -143,10 +143,7 @@ class NewVM(unittest.TestCase):
 
         version = uiutils.find_pattern(newvm, "install-os-version-label")
         time.sleep(1)
-        while True:
-            if "Detecting" not in version.text:
-                break
-            time.sleep(.5)
+        uiutils.check_in_loop(lambda: "Detecting" not in version.text)
         self.assertEquals(version.text, "Red Hat Enterprise Linux 5.5")
 
         uiutils.find_fuzzy(newvm, "Forward", "button").click()
@@ -157,10 +154,7 @@ class NewVM(unittest.TestCase):
 
         progress = uiutils.find_fuzzy(self.app.root,
             "Creating Virtual Machine", "frame")
-        while True:
-            if not progress.showing:
-                break
-            time.sleep(.5)
+        uiutils.check_in_loop(lambda: not progress.showing)
         time.sleep(.5)
 
         uiutils.find_fuzzy(self.app.root, "rhel5.5 on", "frame")

tests/uitests/utils.py

@@ -139,3 +139,19 @@ def print_nodes(root):
             print "got exception: %s" % e
 
     root.findChildren(_walk, isLambda=True)
+
+
+def check_in_loop(func, timeout=-1):
+    """
+    Run the passed func in a loop every .5 seconds until timeout is hit or
+    the func returns True.
+    If timeout=-1, check indefinitely.
+    """
+    total_time = 0.0
+    while True:
+        time.sleep(.5)
+        total_time += .5
+        if func() is True:
+            return
+        if timeout > 0 and total_time >= timeout:
+            raise RuntimeError("Loop condition wasn't met")