Allow jumping to next/previous title in "play all" mode

(EMCGeneralPlayerActions nextTitle/prevTitle on long KEY_CHANNELUP/..DOWN)

src/EMCMediaCenter.py

@@ -330,14 +330,27 @@ def __onShow(self):
 			if self.service and self.service.type != sidDVB:
 				self.realSeekLength = self.getSeekLength()
 
-	def evEOF(self, needToClose=False):
+	def evEOF(self, needToClose=False, prevTitle=False):
 		# see if there are more to play
 		print "EMC PLAYER evEOF", self.playall, self.playcount, self.playlist
 		if self.playall:
 			# Play All
 			try:
-				self.playcount = -1
-				self.playlist = [ self.playall.next() ]
+				# for being able to jump back in 'playall' mode, new titles are added to the playlist acting like a cache
+				# (the generator 'getNextService' cannot easily be made bidirectional, using os.walk)
+				if prevTitle:
+					if self.playcount > 0:
+						self.playcount -= 2
+					else:
+						self.playcount -= 1
+				else:
+					if self.playcount == -1:
+						self.playall.next()
+					elif (self.playcount + 1) == len(self.playlist):
+						self.playlist.append(self.playall.next())
+						if len(self.playlist) > 25:
+							del self.playlist[0]
+							self.playcount -= 1
 			except StopIteration:
 				self.playall = None
 				self.playlist = []
@@ -763,7 +776,7 @@ def nextTitle(self):
 					# InfoBarSeek
 					self.showAfterSeek()
 		else:
-			if len(self.playlist) > 1:
+			if (len(self.playlist) > 1) or self.playall:
 				self.evEOF(False)
 
 	def prevTitle(self):
@@ -773,7 +786,9 @@ def prevTitle(self):
 					# InfoBarSeek
 					self.showAfterSeek()
 		else:
-			if len(self.playlist) > 1:
+			if self.playall:
+				self.evEOF(False,True) # True=previous
+			elif len(self.playlist) > 1:
 				if self.playcount >= 1:
 					self.playcount -= 2
 					self.evEOF(False)