1 files changed, 58 insertions, 0 deletions
diff --git a/xbmc/interfaces/legacy/CallbackHandler.h b/xbmc/interfaces/legacy/CallbackHandler.h
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+++ b/xbmc/interfaces/legacy/CallbackHandler.h
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+/*
+ *  Copyright (C) 2005-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#pragma once
+
+#include "AddonClass.h"
+#include "CallbackFunction.h"
+
+namespace XBMCAddon
+{
+  /**
+   * This is the abstraction representing different ways to handle
+   *  the execution of callbacks. Different language bindings may
+   *  have different requirements.
+   */
+  class CallbackHandler : public AddonClass
+  {
+  protected:
+    inline CallbackHandler() = default;
+
+  public:
+    virtual void invokeCallback(Callback* cb) = 0;
+  };
+
+  /**
+   * This class is primarily for Python support (hence the "Retarded"
+   *  prefix). Python (et. al. Retarded languages) require that
+   *  the context within which a callback executes is under the control
+   *  of the language. Therefore, this handler is used to queue
+   *  messages over to a language controlled thread for eventual
+   *  execution.
+   *
+   * @todo Allow a cross thread synchronous execution.
+   * Fix the stupid means of calling the clearPendingCalls by passing
+   *  userData which is specific to the handler/language type.
+   */
+  class RetardedAsyncCallbackHandler : public CallbackHandler
+  {
+  protected:
+    inline RetardedAsyncCallbackHandler() = default;
+  public:
+
+    ~RetardedAsyncCallbackHandler() override;
+
+    void invokeCallback(Callback* cb) override;
+    static void makePendingCalls();
+    static void clearPendingCalls(void* userData);
+
+    virtual bool isStateOk(AddonClass* obj) =  0;
+    virtual bool shouldRemoveCallback(AddonClass* obj, void* userData) = 0;
+  };
+
+}