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Diffstat (limited to 'src/multimedia/mediaservices/base/qmediaplaylistnavigator.cpp')
| -rw-r--r-- | src/multimedia/mediaservices/base/qmediaplaylistnavigator.cpp | 545 |
1 files changed, 545 insertions, 0 deletions
diff --git a/src/multimedia/mediaservices/base/qmediaplaylistnavigator.cpp b/src/multimedia/mediaservices/base/qmediaplaylistnavigator.cpp new file mode 100644 index 0000000..e3eec5e --- /dev/null +++ b/src/multimedia/mediaservices/base/qmediaplaylistnavigator.cpp @@ -0,0 +1,545 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtMediaServices module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QtMediaServices/qmediaplaylistnavigator.h> +#include <QtMediaServices/qmediaplaylistprovider.h> +#include <QtMediaServices/qmediaplaylist.h> +#include "qmediaobject_p.h" + +#include <QtCore/qdebug.h> + +QT_BEGIN_NAMESPACE + +class QMediaPlaylistNullProvider : public QMediaPlaylistProvider +{ +public: + QMediaPlaylistNullProvider() :QMediaPlaylistProvider() {} + virtual ~QMediaPlaylistNullProvider() {} + virtual int mediaCount() const {return 0;} + virtual QMediaContent media(int) const { return QMediaContent(); } +}; + +Q_GLOBAL_STATIC(QMediaPlaylistNullProvider, _q_nullMediaPlaylist) + +class QMediaPlaylistNavigatorPrivate +{ + Q_DECLARE_NON_CONST_PUBLIC(QMediaPlaylistNavigator) +public: + QMediaPlaylistNavigatorPrivate() + :playlist(0), + currentPos(-1), + lastValidPos(-1), + playbackMode(QMediaPlaylist::Linear), + randomPositionsOffset(-1) + { + } + + QMediaPlaylistProvider *playlist; + int currentPos; + int lastValidPos; //to be used with CurrentItemOnce playback mode + QMediaPlaylist::PlaybackMode playbackMode; + QMediaContent currentItem; + + mutable QList<int> randomModePositions; + mutable int randomPositionsOffset; + + int nextItemPos(int steps = 1) const; + int previousItemPos(int steps = 1) const; + + void _q_mediaInserted(int start, int end); + void _q_mediaRemoved(int start, int end); + void _q_mediaChanged(int start, int end); + + QMediaPlaylistNavigator *q_ptr; +}; + + +int QMediaPlaylistNavigatorPrivate::nextItemPos(int steps) const +{ + if (playlist->mediaCount() == 0) + return -1; + + if (steps == 0) + return currentPos; + + switch (playbackMode) { + case QMediaPlaylist::CurrentItemOnce: + return /*currentPos == -1 ? lastValidPos :*/ -1; + case QMediaPlaylist::CurrentItemInLoop: + return currentPos; + case QMediaPlaylist::Linear: + { + int nextPos = currentPos+steps; + return nextPos < playlist->mediaCount() ? nextPos : -1; + } + case QMediaPlaylist::Loop: + return (currentPos+steps) % playlist->mediaCount(); + case QMediaPlaylist::Random: + { + //TODO: limit the history size + + if (randomPositionsOffset == -1) { + randomModePositions.clear(); + randomModePositions.append(currentPos); + randomPositionsOffset = 0; + } + + while (randomModePositions.size() < randomPositionsOffset+steps+1) + randomModePositions.append(-1); + int res = randomModePositions[randomPositionsOffset+steps]; + if (res<0 || res >= playlist->mediaCount()) { + res = qrand() % playlist->mediaCount(); + randomModePositions[randomPositionsOffset+steps] = res; + } + + return res; + } + } + + return -1; +} + +int QMediaPlaylistNavigatorPrivate::previousItemPos(int steps) const +{ + if (playlist->mediaCount() == 0) + return -1; + + if (steps == 0) + return currentPos; + + switch (playbackMode) { + case QMediaPlaylist::CurrentItemOnce: + return /*currentPos == -1 ? lastValidPos :*/ -1; + case QMediaPlaylist::CurrentItemInLoop: + return currentPos; + case QMediaPlaylist::Linear: + { + int prevPos = currentPos == -1 ? playlist->mediaCount() - steps : currentPos - steps; + return prevPos>=0 ? prevPos : -1; + } + case QMediaPlaylist::Loop: + { + int prevPos = currentPos - steps; + while (prevPos<0) + prevPos += playlist->mediaCount(); + return prevPos; + } + case QMediaPlaylist::Random: + { + //TODO: limit the history size + + if (randomPositionsOffset == -1) { + randomModePositions.clear(); + randomModePositions.append(currentPos); + randomPositionsOffset = 0; + } + + while (randomPositionsOffset-steps < 0) { + randomModePositions.prepend(-1); + randomPositionsOffset++; + } + + int res = randomModePositions[randomPositionsOffset-steps]; + if (res<0 || res >= playlist->mediaCount()) { + res = qrand() % playlist->mediaCount(); + randomModePositions[randomPositionsOffset-steps] = res; + } + + return res; + } + } + + return -1; +} + +/*! + \class QMediaPlaylistNavigator + \preliminary + \since 4.7 + \brief The QMediaPlaylistNavigator class provides navigation for a media playlist. + + \sa QMediaPlaylist, QMediaPlaylistProvider +*/ + + +/*! + Constructs a media playlist navigator for a \a playlist. + + The \a parent is passed to QObject. + */ +QMediaPlaylistNavigator::QMediaPlaylistNavigator(QMediaPlaylistProvider *playlist, QObject *parent) + : QObject(parent) + , d_ptr(new QMediaPlaylistNavigatorPrivate) +{ + d_ptr->q_ptr = this; + + setPlaylist(playlist ? playlist : _q_nullMediaPlaylist()); +} + +/*! + Destroys a media playlist navigator. + */ + +QMediaPlaylistNavigator::~QMediaPlaylistNavigator() +{ + delete d_ptr; +} + + +/*! \property QMediaPlaylistNavigator::playbackMode + Contains the playback mode. + */ +QMediaPlaylist::PlaybackMode QMediaPlaylistNavigator::playbackMode() const +{ + return d_func()->playbackMode; +} + +/*! + Sets the playback \a mode. + */ +void QMediaPlaylistNavigator::setPlaybackMode(QMediaPlaylist::PlaybackMode mode) +{ + Q_D(QMediaPlaylistNavigator); + if (d->playbackMode == mode) + return; + + if (mode == QMediaPlaylist::Random) { + d->randomPositionsOffset = 0; + d->randomModePositions.append(d->currentPos); + } else if (d->playbackMode == QMediaPlaylist::Random) { + d->randomPositionsOffset = -1; + d->randomModePositions.clear(); + } + + d->playbackMode = mode; + + emit playbackModeChanged(mode); + emit surroundingItemsChanged(); +} + +/*! + Returns the playlist being navigated. +*/ + +QMediaPlaylistProvider *QMediaPlaylistNavigator::playlist() const +{ + return d_func()->playlist; +} + +/*! + Sets the \a playlist to navigate. +*/ +void QMediaPlaylistNavigator::setPlaylist(QMediaPlaylistProvider *playlist) +{ + Q_D(QMediaPlaylistNavigator); + + if (d->playlist == playlist) + return; + + if (d->playlist) { + d->playlist->disconnect(this); + } + + if (playlist) { + d->playlist = playlist; + } else { + //assign to shared readonly null playlist + d->playlist = _q_nullMediaPlaylist(); + } + + connect(d->playlist, SIGNAL(mediaInserted(int,int)), SLOT(_q_mediaInserted(int,int))); + connect(d->playlist, SIGNAL(mediaRemoved(int,int)), SLOT(_q_mediaRemoved(int,int))); + connect(d->playlist, SIGNAL(mediaChanged(int,int)), SLOT(_q_mediaChanged(int,int))); + + d->randomPositionsOffset = -1; + d->randomModePositions.clear(); + + if (d->currentPos != -1) { + d->currentPos = -1; + emit currentIndexChanged(-1); + } + + if (!d->currentItem.isNull()) { + d->currentItem = QMediaContent(); + emit activated(d->currentItem); //stop playback + } +} + +/*! \property QMediaPlaylistNavigator::currentItem + + Contains the media at the current position in the playlist. + + \sa currentIndex() +*/ + +QMediaContent QMediaPlaylistNavigator::currentItem() const +{ + return itemAt(d_func()->currentPos); +} + +/*! \fn QMediaContent QMediaPlaylistNavigator::nextItem(int steps) const + + Returns the media that is \a steps positions ahead of the current + position in the playlist. + + \sa nextIndex() +*/ +QMediaContent QMediaPlaylistNavigator::nextItem(int steps) const +{ + return itemAt(nextIndex(steps)); +} + +/*! + Returns the media that is \a steps positions behind the current + position in the playlist. + + \sa previousIndex() + */ +QMediaContent QMediaPlaylistNavigator::previousItem(int steps) const +{ + return itemAt(previousIndex(steps)); +} + +/*! + Returns the media at a \a position in the playlist. + */ +QMediaContent QMediaPlaylistNavigator::itemAt(int position) const +{ + return d_func()->playlist->media(position); +} + +/*! \property QMediaPlaylistNavigator::currentIndex + + Contains the position of the current media. + + If no media is current, the property contains -1. + + \sa nextIndex(), previousIndex() +*/ + +int QMediaPlaylistNavigator::currentIndex() const +{ + return d_func()->currentPos; +} + +/*! + Returns a position \a steps ahead of the current position + accounting for the playbackMode(). + + If the position is beyond the end of the playlist, this value + returned is -1. + + \sa currentIndex(), previousIndex(), playbackMode() +*/ + +int QMediaPlaylistNavigator::nextIndex(int steps) const +{ + return d_func()->nextItemPos(steps); +} + +/*! + + Returns a position \a steps behind the current position accounting + for the playbackMode(). + + If the position is prior to the beginning of the playlist this will + return -1. + + \sa currentIndex(), nextIndex(), playbackMode() +*/ +int QMediaPlaylistNavigator::previousIndex(int steps) const +{ + return d_func()->previousItemPos(steps); +} + +/*! + Advances to the next item in the playlist. + + \sa previous(), jump(), playbackMode() + */ +void QMediaPlaylistNavigator::next() +{ + Q_D(QMediaPlaylistNavigator); + + int nextPos = d->nextItemPos(); + + if ( playbackMode() == QMediaPlaylist::Random ) + d->randomPositionsOffset++; + + jump(nextPos); +} + +/*! + Returns to the previous item in the playlist, + + \sa next(), jump(), playbackMode() + */ +void QMediaPlaylistNavigator::previous() +{ + Q_D(QMediaPlaylistNavigator); + + int prevPos = d->previousItemPos(); + if ( playbackMode() == QMediaPlaylist::Random ) + d->randomPositionsOffset--; + + jump(prevPos); +} + +/*! + Jumps to a new \a position in the playlist. + */ +void QMediaPlaylistNavigator::jump(int position) +{ + Q_D(QMediaPlaylistNavigator); + + if (position<-1 || position>=d->playlist->mediaCount()) { + qWarning() << "QMediaPlaylistNavigator: Jump outside playlist range"; + position = -1; + } + + if (position != -1) + d->lastValidPos = position; + + if (playbackMode() == QMediaPlaylist::Random) { + if (d->randomModePositions[d->randomPositionsOffset] != position) { + d->randomModePositions.clear(); + d->randomModePositions.append(position); + d->randomPositionsOffset = 0; + } + } + + if (position != -1) + d->currentItem = d->playlist->media(position); + else + d->currentItem = QMediaContent(); + + if (position != d->currentPos) { + d->currentPos = position; + emit currentIndexChanged(d->currentPos); + emit surroundingItemsChanged(); + } + + emit activated(d->currentItem); +} + +/*! + \internal +*/ +void QMediaPlaylistNavigatorPrivate::_q_mediaInserted(int start, int end) +{ + Q_Q(QMediaPlaylistNavigator); + + if (currentPos >= start) { + currentPos = end-start+1; + q->jump(currentPos); + } + + //TODO: check if they really changed + emit q->surroundingItemsChanged(); +} + +/*! + \internal +*/ +void QMediaPlaylistNavigatorPrivate::_q_mediaRemoved(int start, int end) +{ + Q_Q(QMediaPlaylistNavigator); + + if (currentPos > end) { + currentPos = currentPos - end-start+1; + q->jump(currentPos); + } else if (currentPos >= start) { + //current item was removed + currentPos = qMin(start, playlist->mediaCount()-1); + q->jump(currentPos); + } + + //TODO: check if they really changed + emit q->surroundingItemsChanged(); +} + +/*! + \internal +*/ +void QMediaPlaylistNavigatorPrivate::_q_mediaChanged(int start, int end) +{ + Q_Q(QMediaPlaylistNavigator); + + if (currentPos >= start && currentPos<=end) { + QMediaContent src = playlist->media(currentPos); + if (src != currentItem) { + currentItem = src; + emit q->activated(src); + } + } + + //TODO: check if they really changed + emit q->surroundingItemsChanged(); +} + +/*! + \fn QMediaPlaylistNavigator::activated(const QMediaContent &media) + + Signals that the current \a media has changed. +*/ + +/*! + \fn QMediaPlaylistNavigator::currentIndexChanged(int position) + + Signals the \a position of the current media has changed. +*/ + +/*! + \fn QMediaPlaylistNavigator::playbackModeChanged(QMediaPlaylist::PlaybackMode mode) + + Signals that the playback \a mode has changed. +*/ + +/*! + \fn QMediaPlaylistNavigator::surroundingItemsChanged() + + Signals that media immediately surrounding the current position has changed. +*/ + +#include "moc_qmediaplaylistnavigator.cpp" + +QT_END_NAMESPACE + |