Merge lp:~trb143/openlp/bug-892571 into lp:openlp

[Tim Bentley]

Stop keyboard floods getting the slide controller and service manager out of set.
Key presses are only accepted when the previous updates have happened.

To Test set preview next song to on.
Add 5 songs to service manager
Select the first one.
Press the right arrow key fast.

[Andreas Preikschat (googol-deactivatedaccount)]

Now "right arrow", "right arrow" does not work (only the first "right arrow" is recognised). If I press the "right arrow" twice, I want to go to the song after the next one.

review: Needs Fixing

[Tim Bentley (trb143)]

Well If I use a mutex it locks up.
Without a major (2-3 month) re-write of the code path as it is very long and impacts plugins etc I am not sure what else to try.
The code
   looks up the current selected service item
   Selects the next one.
   Flushes the events to add a cursor
   Adds a service item
   This signals plugins twice to turn off and then hand new service item.
   selects the next service item to preview it.
   Flushes the events to remove the cursor

The Keyboard will start this flow BEFORE the previous has finished so you get a number of calling chains running at the same time.

[Andreas Preikschat (googol-deactivatedaccount)]

I just do not think this is the right attempt. I see that it is difficult (impossible ?) to fix this!?

[lp:~trb143/openlp/bug-892571]

1802. By Tim Bentley on 2011-11-27

Move to reference counting

1803. By Tim Bentley on 2011-11-28

Implement a queue to process the requests

1804. By Tim Bentley on 2011-11-28

Fix double loop entry

Unmerged revisions

=== modified file 'openlp/core/ui/slidecontroller.py'
--- openlp/core/ui/slidecontroller.py	2011-10-31 09:14:07 +0000
+++ openlp/core/ui/slidecontroller.py	2011-11-27 16:12:24 +0000
@@ -79,6 +79,7 @@
         self.songEdit = False
         self.selectedRow = 0
         self.serviceItem = None
+        self.keypress_count = 0
         self.panel = QtGui.QWidget(parent.controlSplitter)
         self.slideList = {}
         # Layout for holding panel
@@ -578,12 +579,19 @@
         self.display.videoStop()
 
     def servicePrevious(self):
-        time.sleep(0.1)
-        Receiver.send_message('servicemanager_previous_item')
+        self.keypress_count += 1
+        if self.keypress_count == 1:
+            while self.keypress_count != 0:
+                Receiver.send_message('servicemanager_previous_item')
+                self.keypress_count -= 1             
 
     def serviceNext(self):
-        time.sleep(0.1)
-        Receiver.send_message('servicemanager_next_item')
+        self.keypress_count += 1
+        if self.keypress_count == 1:
+            while self.keypress_count != 0:
+                Receiver.send_message('servicemanager_next_item')
+                self.keypress_count -= 1            
+     
 
     def screenSizeChanged(self):
         """
@@ -771,7 +779,7 @@
         log.debug(u'processManagerItem live = %s' % self.isLive)
         self.onStopLoop()
         old_item = self.serviceItem
-        # take a copy not a link to the servicemeanager copy.
+        # take a copy not a link to the servicemanager copy.
         self.serviceItem = copy.copy(serviceItem)
         if old_item and self.isLive and old_item.is_capable(
             ItemCapabilities.ProvidesOwnDisplay):