xbmc/interfaces/legacy/CallbackHandler.h

   1 /*
   2  *  Copyright (C) 2005-2018 Team Kodi
   3  *  This file is part of Kodi - https://kodi.tv
   4  *
   5  *  SPDX-License-Identifier: GPL-2.0-or-later
   6  *  See LICENSES/README.md for more information.
   7  */
   8
   9 #pragma once
  10
  11 #include "AddonClass.h"
  12 #include "CallbackFunction.h"
  13
  14 namespace XBMCAddon
  15 {
  16   /**
  17    * This is the abstraction representing different ways to handle
  18    *  the execution of callbacks. Different language bindings may
  19    *  have different requirements.
  20    */
  21   class CallbackHandler : public AddonClass
  22   {
  23   protected:
  24     inline CallbackHandler() = default;
  25
  26   public:
  27     virtual void invokeCallback(Callback* cb) = 0;
  28   };
  29
  30   /**
  31    * This class is primarily for Python support (hence the "Retarded"
  32    *  prefix). Python (et. al. Retarded languages) require that
  33    *  the context within which a callback executes is under the control
  34    *  of the language. Therefore, this handler is used to queue
  35    *  messages over to a language controlled thread for eventual
  36    *  execution.
  37    *
  38    * @todo Allow a cross thread synchronous execution.
  39    * Fix the stupid means of calling the clearPendingCalls by passing
  40    *  userData which is specific to the handler/language type.
  41    */
  42   class RetardedAsyncCallbackHandler : public CallbackHandler
  43   {
  44   protected:
  45     inline RetardedAsyncCallbackHandler() = default;
  46   public:
  47
  48     ~RetardedAsyncCallbackHandler() override;
  49
  50     void invokeCallback(Callback* cb) override;
  51     static void makePendingCalls();
  52     static void clearPendingCalls(void* userData);
  53
  54     virtual bool isStateOk(AddonClass* obj) =  0;
  55     virtual bool shouldRemoveCallback(AddonClass* obj, void* userData) = 0;
  56   };
  57
  58 }