source/modules/juce_events/broadcasters/juce_ChangeBroadcaster.cpp

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library.
   5    Copyright (c) 2022 - Raw Material Software Limited
   6
   7    JUCE is an open source library subject to commercial or open-source
   8    licensing.
   9
  10    The code included in this file is provided under the terms of the ISC license
  11    http://www.isc.org/downloads/software-support-policy/isc-license. Permission
  12    To use, copy, modify, and/or distribute this software for any purpose with or
  13    without fee is hereby granted provided that the above copyright notice and
  14    this permission notice appear in all copies.
  15
  16    JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
  17    EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
  18    DISCLAIMED.
  19
  20   ==============================================================================
  21 */
  22
  23 namespace juce
  24 {
  25
  26 ChangeBroadcaster::ChangeBroadcaster() noexcept
  27 {
  28     broadcastCallback.owner = this;
  29 }
  30
  31 ChangeBroadcaster::~ChangeBroadcaster()
  32 {
  33 }
  34
  35 void ChangeBroadcaster::addChangeListener (ChangeListener* const listener)
  36 {
  37     // Listeners can only be safely added when the event thread is locked
  38     // You can  use a MessageManagerLock if you need to call this from another thread.
  39     JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED
  40
  41     changeListeners.add (listener);
  42     anyListeners = true;
  43 }
  44
  45 void ChangeBroadcaster::removeChangeListener (ChangeListener* const listener)
  46 {
  47     // Listeners can only be safely removed when the event thread is locked
  48     // You can  use a MessageManagerLock if you need to call this from another thread.
  49     JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED
  50
  51     changeListeners.remove (listener);
  52     anyListeners = changeListeners.size() > 0;
  53 }
  54
  55 void ChangeBroadcaster::removeAllChangeListeners()
  56 {
  57     // Listeners can only be safely removed when the event thread is locked
  58     // You can  use a MessageManagerLock if you need to call this from another thread.
  59     JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED
  60
  61     changeListeners.clear();
  62     anyListeners = false;
  63 }
  64
  65 void ChangeBroadcaster::sendChangeMessage()
  66 {
  67     if (anyListeners)
  68         broadcastCallback.triggerAsyncUpdate();
  69 }
  70
  71 void ChangeBroadcaster::sendSynchronousChangeMessage()
  72 {
  73     // This can only be called by the event thread.
  74     JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED
  75
  76     broadcastCallback.cancelPendingUpdate();
  77     callListeners();
  78 }
  79
  80 void ChangeBroadcaster::dispatchPendingMessages()
  81 {
  82     broadcastCallback.handleUpdateNowIfNeeded();
  83 }
  84
  85 void ChangeBroadcaster::callListeners()
  86 {
  87     changeListeners.call ([this] (ChangeListener& l) { l.changeListenerCallback (this); });
  88 }
  89
  90 //==============================================================================
  91 ChangeBroadcaster::ChangeBroadcasterCallback::ChangeBroadcasterCallback()
  92     : owner (nullptr)
  93 {
  94 }
  95
  96 void ChangeBroadcaster::ChangeBroadcasterCallback::handleAsyncUpdate()
  97 {
  98     jassert (owner != nullptr);
  99     owner->callListeners();
 100 }
 101
 102 } // namespace juce