Workaround for windows display not updating, webkit player does not work yet. Partial fix for bug 1531319.

Fixes: https://launchpad.net/bugs/1531319

openlp/core/ui/maindisplay.py

@@ -90,7 +90,7 @@ class Display(QtWidgets.QGraphicsView):
         # OpenGL. Only white blank screen is shown on the 2nd monitor all the
         # time. We need to investigate more how to use OpenGL properly on Mac OS
         # X.
-        if not is_macosx() and not is_win():
+        if not is_macosx():
             self.setViewport(QtOpenGL.QGLWidget())
 
     def setup(self):
@@ -559,6 +559,13 @@ class MainDisplay(OpenLPMixin, Display, RegistryProperties):
                     if window_id == main_window_id:
                         self.main_window.raise_()
 
+    def shake_web_view(self):
+        """
+        Resizes the web_view a bit to force an update. Workaround for bug #1531319, should not be needed with PyQt 5.6. 
+        """
+        self.web_view.setGeometry(0, 0, self.width(), self.height()-1)
+        self.web_view.setGeometry(0, 0, self.width(), self.height())
+
 
 class AudioPlayer(OpenLPMixin, QtCore.QObject):
     """

openlp/core/ui/slidecontroller.py

@@ -31,7 +31,7 @@ from threading import Lock
 from PyQt5 import QtCore, QtGui, QtWidgets
 
 from openlp.core.common import Registry, RegistryProperties, Settings, SlideLimits, UiStrings, translate, \
-    RegistryMixin, OpenLPMixin
+    RegistryMixin, OpenLPMixin, is_win
 from openlp.core.lib import OpenLPToolbar, ItemCapabilities, ServiceItem, ImageSource, ServiceItemAction, \
     ScreenList, build_icon, build_html
 from openlp.core.ui import HideMode, MainDisplay, Display, DisplayControllerType
@@ -1101,6 +1101,9 @@ class SlideController(DisplayController, RegistryProperties):
                         self.display.image(to_display)
                     # reset the store used to display first image
                     self.service_item.bg_image_bytes = None
+                # Workaround for bug #1531319, should not be needed with PyQt 5.6. 
+                if self.is_live and is_win():
+                    self.display.shake_web_view()
             self.selected_row = row
             self.update_preview()
             self.preview_widget.change_slide(row)