inform the user, that he has to restart openlp if he wants changes to the monitor set up to be available

openlp.pyw

@@ -34,7 +34,8 @@ from subprocess import Popen, PIPE
 
 from PyQt4 import QtCore, QtGui
 
-from openlp.core.lib import Receiver, check_directory_exists
+from openlp.core.lib import Receiver, translate, check_directory_exists
+from openlp.core.lib.ui import information_message_box
 from openlp.core.resources import qInitResources
 from openlp.core.ui.mainwindow import MainWindow
 from openlp.core.ui.exceptionform import ExceptionForm
@@ -166,6 +167,9 @@ class OpenLP(QtGui.QApplication):
             QtCore.SIGNAL(u'cursor_busy'), self.setBusyCursor)
         QtCore.QObject.connect(Receiver.get_receiver(),
             QtCore.SIGNAL(u'cursor_normal'), self.setNormalCursor)
+        QtCore.QObject.connect(self.desktop(),
+            QtCore.SIGNAL(u'screenCountChanged(int)'),
+            self.onScreenCountChanged)
         self.setOrganizationName(u'OpenLP')
         self.setOrganizationDomain(u'openlp.org')
         self.setApplicationName(u'OpenLP')
@@ -225,6 +229,15 @@ class OpenLP(QtGui.QApplication):
         """
         self.restoreOverrideCursor()
 
+    def onScreenCountChanged(self):
+        """
+        Called when the user changes the monitor set up.
+        """
+        information_message_box(
+            message=translate('OpenLP','You have changed the monitor set up. '
+            'You have to restart OpenLP in order to change the live display '
+            'monitor.'))
+
 def main():
     """
     The main function which parses command line options and then runs

openlp/core/lib/ui.py

@@ -58,6 +58,7 @@ class UiStrings(object):
         'Abbreviated font pointsize unit')
     Image = translate('OpenLP.Ui', 'Image')
     Import = translate('OpenLP.Ui', 'Import')
+    Information = translate('OpenLP.Ui', 'Information')
     LengthTime = unicode(translate('OpenLP.Ui', 'Length %s'))
     Live = translate('OpenLP.Ui', 'Live')
     LiveBGError = translate('OpenLP.Ui', 'Live Background Error')
@@ -173,6 +174,32 @@ def critical_error_message_box(title=None, message=None, parent=None,
     data[u'title'] = title if title else UiStrings.Error
     return Receiver.send_message(u'openlp_error_message', data)
 
+def information_message_box(title=None, message=None, parent=None,
+    question=False):
+    """
+    Provides a standard information message box for notes that OpenLP displays
+    to users.
+
+    ``title``
+        The title for the message box.
+
+    ``message``
+        The message to display to the user.
+
+    ``parent``
+        The parent UI element to attach the dialog to.
+
+    ``question``
+        Should this message box question the user.
+    """
+    if question:
+        return QtGui.QMessageBox.critical(parent, UiStrings.Information,
+            message, QtGui.QMessageBox.StandardButtons(
+            QtGui.QMessageBox.Yes | QtGui.QMessageBox.No))
+    data = {u'message': message}
+    data[u'title'] = title if title else UiStrings.Information
+    return Receiver.send_message(u'openlp_information_message', data)
+
 def media_item_combo_box(parent, name):
     """
     Provide a standard combo box for media items.