The main bits of this implementation are:
- Start a new track in paused state. We don't care about the actual
media state or player state that QMediaPlayer is reporting. We will
deal with that when the audio actually starts playing.
- If a player position needs to be restored, we set d->m_pendingSeek to
the position that needs to be seeked. We don't actually seek because
we have no idea what state the player is in yet.
- On the positionChanged signal of QMP, and if the media is buffered, we
check if there is pendingSeek value set which is set to a different
value than the current player position. If so, we call
d->m_player.setPosition(). If we have arrived at the correct
position, then we reset d->m_pendingSeek to -1.
- In the position(), duration() and seek() methods, we return sensible
values, even QMP is not. So, we report the duration from the
enclosure, the position from d->m_pendingSeek, and let seek() change
the value of d->m_PendingSeek (if it's not -1) to the new seek
position.
- When there's a pending seek, we set the notifyInterval to shorter
interval to reduce the startup audio glitch as much as possible. We
then reset it to the default of 1000 msec.
This was tested on linux and android.
AudioManager is currently owned by qml, so it's highly confusing to have
this routine, since it would give a pointer to another instance than the
one owned by qml.
Both classes are based on classes taken from Elisa.
The audiomanager class will be adapted to add functionality like saving
and restoring play positions and interfacing with MPRIS2.
