juce/source/src/audio/midi/juce_MidiMessageCollector.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #ifndef __JUCE_MIDIMESSAGECOLLECTOR_JUCEHEADER__
  27 #define __JUCE_MIDIMESSAGECOLLECTOR_JUCEHEADER__
  28
  29 #include "juce_MidiInput.h"
  30 #include "juce_MidiKeyboardState.h"
  31
  32
  33 //==============================================================================
  34 /**
  35     Collects incoming realtime MIDI messages and turns them into blocks suitable for
  36     processing by a block-based audio callback.
  37
  38     The class can also be used as either a MidiKeyboardStateListener or a MidiInputCallback
  39     so it can easily use a midi input or keyboard component as its source.
  40
  41     @see MidiMessage, MidiInput
  42 */
  43 class JUCE_API  MidiMessageCollector    : public MidiKeyboardStateListener,
  44                                           public MidiInputCallback
  45 {
  46 public:
  47     //==============================================================================
  48     /** Creates a MidiMessageCollector. */
  49     MidiMessageCollector();
  50
  51     /** Destructor. */
  52     ~MidiMessageCollector();
  53
  54     //==============================================================================
  55     /** Clears any messages from the queue.
  56
  57         You need to call this method before starting to use the collector, so that
  58         it knows the correct sample rate to use.
  59     */
  60     void reset (double sampleRate);
  61
  62     /** Takes an incoming real-time message and adds it to the queue.
  63
  64         The message's timestamp is taken, and it will be ready for retrieval as part
  65         of the block returned by the next call to removeNextBlockOfMessages().
  66
  67         This method is fully thread-safe when overlapping calls are made with
  68         removeNextBlockOfMessages().
  69     */
  70     void addMessageToQueue (const MidiMessage& message);
  71
  72     /** Removes all the pending messages from the queue as a buffer.
  73
  74         This will also correct the messages' timestamps to make sure they're in
  75         the range 0 to numSamples - 1.
  76
  77         This call should be made regularly by something like an audio processing
  78         callback, because the time that it happens is used in calculating the
  79         midi event positions.
  80
  81         This method is fully thread-safe when overlapping calls are made with
  82         addMessageToQueue().
  83     */
  84     void removeNextBlockOfMessages (MidiBuffer& destBuffer, int numSamples);
  85
  86
  87     //==============================================================================
  88     /** @internal */
  89     void handleNoteOn (MidiKeyboardState* source, int midiChannel, int midiNoteNumber, float velocity);
  90     /** @internal */
  91     void handleNoteOff (MidiKeyboardState* source, int midiChannel, int midiNoteNumber);
  92     /** @internal */
  93     void handleIncomingMidiMessage (MidiInput* source, const MidiMessage& message);
  94
  95 private:
  96     //==============================================================================
  97     double lastCallbackTime;
  98     CriticalSection midiCallbackLock;
  99     MidiBuffer incomingMessages;
 100     double sampleRate;
 101
 102     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MidiMessageCollector);
 103 };
 104
 105
 106 #endif   // __JUCE_MIDIMESSAGECOLLECTOR_JUCEHEADER__