I04_1-156: messages have a lifetime. Added scan timeout message

Author: IsabellaRey

dls_barcode/gui/main_window.py

@@ -230,7 +230,7 @@ def _read_side_scan(self):
     def _read_top_scan(self):
         if self._result_queue.empty():
             if self._camera_switch.is_top_scan_timeout():
-                self._message_display.display_message(Message(MessageType.INFO, "Scan timeout"))
+                self._message_display.display_message(Message(MessageType.INFO, "Scan timeout", lifetime=4))
                 print("\n*** Scan timeout ***")
                 self._camera_switch.restart_live_capture_from_side()
             return

dls_barcode/gui/message_display.py

@@ -1,10 +1,8 @@
-import time
 from PyQt4.QtGui import QLabel, QGroupBox, QVBoxLayout
 from PyQt4 import QtCore
 
 from dls_util.message import MessageType
 
-MSG_LIFETIME = 2
 
 class MessageDisplay(QGroupBox):
     """GUI component. Displays messages for the user."""
@@ -35,11 +33,11 @@ def _init_ui(self):
         self.setLayout(vbox)
 
     def display_message(self, message):
-        self._message_lbl.setText(message.content())
-        self._message_lbl.setStyleSheet("color: " + self._colors[message.type()])
-        self._latest_message_time = time.time()
+        self._message = message
+        self._message_lbl.setText(self._message.content())
+        self._message_lbl.setStyleSheet("color: " + self._colors[self._message.type()])
 
     def _clear_old_message(self):
-        now = time.time()
-        if self._message_lbl.text() and now - self._latest_message_time > MSG_LIFETIME:
+        if self._message_lbl.text() and self._message.has_expired():
             self._message_lbl.clear()
+            self._message = None

dls_util/message/message.py

@@ -1,11 +1,14 @@
-class Message:
+from dls_util.object_with_lifetime import ObjectWithLifetime
+
+class Message(ObjectWithLifetime):
     """A class that holds a message"""
-    def __init__(self, type, content):
+    def __init__(self, type, content, lifetime=2):
+        ObjectWithLifetime.__init__(self, lifetime)
         self._type = type
         self._content = content
 
     def type(self):
         return self._type
 
     def content(self):
-        return self._content
+        return self._content

dls_util/object_with_lifetime.py

@@ -9,4 +9,4 @@ def __init__(self, lifetime):
         self._start_time = time.time()
 
     def has_expired(self):
-        return (time.time() - self._start_time) > self._lifetime
+        return (time.time() - self._start_time) > self._lifetime