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118 lines
4.3 KiB
C++
118 lines
4.3 KiB
C++
/*
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==============================================================================
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This file is part of the JUCE framework.
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Copyright (c) Raw Material Software Limited
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JUCE is an open source framework subject to commercial or open source
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licensing.
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By downloading, installing, or using the JUCE framework, or combining the
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JUCE framework with any other source code, object code, content or any other
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copyrightable work, you agree to the terms of the JUCE End User Licence
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Agreement, and all incorporated terms including the JUCE Privacy Policy and
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the JUCE Website Terms of Service, as applicable, which will bind you. If you
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do not agree to the terms of these agreements, we will not license the JUCE
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framework to you, and you must discontinue the installation or download
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process and cease use of the JUCE framework.
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JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
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JUCE Privacy Policy: https://juce.com/juce-privacy-policy
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JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/
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Or:
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You may also use this code under the terms of the AGPLv3:
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https://www.gnu.org/licenses/agpl-3.0.en.html
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THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
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WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
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MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.
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==============================================================================
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*/
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namespace juce
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{
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//==============================================================================
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/**
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Holds a list of ChangeListeners, and sends messages to them when instructed.
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@see ChangeListener
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@tags{Events}
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*/
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class JUCE_API ChangeBroadcaster
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{
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public:
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//==============================================================================
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/** Creates an ChangeBroadcaster. */
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ChangeBroadcaster() noexcept;
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/** Destructor. */
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virtual ~ChangeBroadcaster();
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//==============================================================================
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/** Registers a listener to receive change callbacks from this broadcaster.
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Trying to add a listener that's already on the list will have no effect.
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*/
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void addChangeListener (ChangeListener* listener);
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/** Unregisters a listener from the list.
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If the listener isn't on the list, this won't have any effect.
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*/
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void removeChangeListener (ChangeListener* listener);
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/** Removes all listeners from the list. */
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void removeAllChangeListeners();
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//==============================================================================
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/** Causes an asynchronous change message to be sent to all the registered listeners.
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The message will be delivered asynchronously by the main message thread, so this
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method will return immediately. To call the listeners synchronously use
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sendSynchronousChangeMessage().
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*/
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void sendChangeMessage();
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/** Sends a synchronous change message to all the registered listeners.
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This will immediately call all the listeners that are registered. For thread-safety
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reasons, you must only call this method on the main message thread.
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@see dispatchPendingMessages
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*/
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void sendSynchronousChangeMessage();
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/** If a change message has been sent but not yet dispatched, this will call
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sendSynchronousChangeMessage() to make the callback immediately.
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For thread-safety reasons, you must only call this method on the main message thread.
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*/
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void dispatchPendingMessages();
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private:
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//==============================================================================
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class ChangeBroadcasterCallback : public AsyncUpdater
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{
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public:
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ChangeBroadcasterCallback();
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~ChangeBroadcasterCallback() override { cancelPendingUpdate(); }
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void handleAsyncUpdate() override;
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ChangeBroadcaster* owner;
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};
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friend class ChangeBroadcasterCallback;
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ChangeBroadcasterCallback broadcastCallback;
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ListenerList <ChangeListener> changeListeners;
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std::atomic<bool> anyListeners { false };
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void callListeners();
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JUCE_DECLARE_NON_COPYABLE (ChangeBroadcaster)
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};
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} // namespace juce
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