Chris@1651: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@1651: 
Chris@1651: /*
Chris@1651:     Sonic Visualiser
Chris@1651:     An audio file viewer and annotation editor.
Chris@1651:     Centre for Digital Music, Queen Mary, University of London.
Chris@1651:     
Chris@1651:     This program is free software; you can redistribute it and/or
Chris@1651:     modify it under the terms of the GNU General Public License as
Chris@1651:     published by the Free Software Foundation; either version 2 of the
Chris@1651:     License, or (at your option) any later version.  See the file
Chris@1651:     COPYING included with this distribution for more information.
Chris@1651: */
Chris@1651: 
Chris@1651: #ifndef SV_DEFERRED_NOTIFIER_H
Chris@1651: #define SV_DEFERRED_NOTIFIER_H
Chris@1651: 
Chris@1651: #include "Model.h"
Chris@1651: 
Chris@1651: #include "base/Extents.h"
Chris@1651: 
Chris@1651: #include <QMutex>
Chris@1651: #include <QMutexLocker>
Chris@1651: 
Chris@1651: class DeferredNotifier
Chris@1651: {
Chris@1651: public:
Chris@1651:     enum Mode {
Chris@1651:         NOTIFY_ALWAYS,
Chris@1651:         NOTIFY_DEFERRED
Chris@1651:     };
Chris@1651:     
Chris@1651:     DeferredNotifier(Model *m, Mode mode) : m_model(m), m_mode(mode) { }
Chris@1651: 
Chris@1651:     Mode getMode() const {
Chris@1651:         return m_mode;
Chris@1651:     }
Chris@1651:     void switchMode(Mode newMode) {
Chris@1651:         m_mode = newMode;
Chris@1651:     }
Chris@1651:     
Chris@1651:     void update(sv_frame_t frame, sv_frame_t duration) {
Chris@1651:         if (m_mode == NOTIFY_ALWAYS) {
Chris@1651:             m_model->modelChangedWithin(frame, frame + duration);
Chris@1651:         } else {
Chris@1651:             QMutexLocker locker(&m_mutex);
Chris@1651:             m_extents.sample(frame);
Chris@1651:             m_extents.sample(frame + duration);
Chris@1651:         }
Chris@1651:     }
Chris@1651:     
Chris@1651:     void makeDeferredNotifications() {
Chris@1651:         bool shouldEmit = false;
Chris@1651:         sv_frame_t from, to;
Chris@1651:         {   QMutexLocker locker(&m_mutex);
Chris@1651:             if (m_extents.isSet()) {
Chris@1651:                 shouldEmit = true;
Chris@1651:                 from = m_extents.getMin();
Chris@1651:                 to = m_extents.getMax();
Chris@1651:             }
Chris@1651:         }
Chris@1651:         if (shouldEmit) {
Chris@1651:             m_model->modelChangedWithin(from, to);
Chris@1651:             QMutexLocker locker(&m_mutex);
Chris@1651:             m_extents.reset();
Chris@1651:         }
Chris@1651:     }
Chris@1651: 
Chris@1651: private:
Chris@1651:     Model *m_model;
Chris@1651:     Mode m_mode;
Chris@1651:     QMutex m_mutex;
Chris@1651:     Extents<sv_frame_t> m_extents;
Chris@1651: };
Chris@1651: 
Chris@1651: #endif