move delay function to gui/utils

1 files changed, 24 insertions, 0 deletions

diff --git a/src/leap/gui/utils.py b/src/leap/gui/utils.py
index 8b1e3630..f91ac3ef 100644
--- a/src/leap/gui/utils.py
+++ b/src/leap/gui/utils.py
@@ -1,6 +1,7 @@
 """
 utility functions to work with gui objects
 """
+from PyQt4 import QtCore
 
 
 def layout_widgets(layout):
@@ -8,3 +9,26 @@ def layout_widgets(layout):
     return a generator with all widgets in a layout
     """
     return (layout.itemAt(i) for i in range(layout.count()))
+
+
+DELAY_MSECS = 50
+
+
+def delay(obj, method_str=None, call_args=None):
+    """
+    Triggers a function or slot with a small delay.
+    this is a mainly a hack to get responsiveness in the ui
+    in cases in which the event loop freezes and the task
+    is not heavy enough to setup a processing queue.
+    """
+    if callable(obj) and not method_str:
+        fun = lambda: obj()
+
+    if method_str:
+        invoke = QtCore.QMetaObject.invokeMethod
+        if call_args:
+            fun = lambda: invoke(obj, method_str, call_args)
+        else:
+            fun = lambda: invoke(obj, method_str)
+
+    QtCore.QTimer().singleShot(DELAY_MSECS, fun)