Class MMidiClientUtilityObserver

class MMidiClientUtilityObserver;

Description

Active object utility class to allow MIDI events to be signalled asynchronously.

Members

Defined in MMidiClientUtilityObserver:
MmcuoInstrumentChanged(), MmcuoMetaDataEntryFound(), MmcuoMipMessageReceived(), MmcuoMuteChanged(), MmcuoPolyphonyChanged(), MmcuoStateChanged(), MmcuoSyncUpdate(), MmcuoTempoChanged(), MmcuoVolumeChanged()

See also:

• CMidiClientUtility::NewL()

virtual void MmcuoStateChanged(TMidiState aOldState, TMidiState aNewState, const TTimeIntervalMicroSeconds &aTime, TInt aError)=0;

Description

A state change has occurred in the MIDI client utility.

Parameters

TMidiState aOldState Old state. TMidiState aNewState New state. const TTimeIntervalMicroSeconds &aTime The time in microseconds at which playback stopped relative to the start of the MIDI resource. TInt aError Error code.

virtual void MmcuoTempoChanged(TInt aMicroBeatsPerMinute)=0;

Description

The MIDI resource has encountered a tempo change message in the MIDI data stream.

Parameters

TInt aMicroBeatsPerMinute New tempo value in micro beats per minute (BPM*1000000).

virtual void MmcuoVolumeChanged(TInt aChannel, TReal32 aVolumeInDecibels)=0;

Description

The MIDI resource has encountered a volume change message in the MIDI data stream.

Parameters

TInt aChannel Logical channel to which the message applies. 0 <= aChannel < ChannelsSupportedL(). TReal32 aVolumeInDecibels New volume setting being used.

virtual void MmcuoMuteChanged(TInt aChannel, TBool aMuted)=0;

Description

The MIDI resource has encountered a mute message in the MIDI data stream.

Parameters

TInt aChannel Logical channel to which the message applies. 0 <= aChannel < ChannelsSupportedL(). TBool aMuted New muting state of the channel - ETrue is muted, EFalse is unmuted.

virtual void MmcuoSyncUpdate(const TTimeIntervalMicroSeconds &aMicroSeconds, TInt64 aMicroBeats)=0;

Description

Callback in response to a call to CMIDIClientUtility::SetSyncUpdateCallbackIntervalL(). By default there are no callbacks. Otherwise the callback is called at an interval set by the client.

Parameters

const TTimeIntervalMicroSeconds &aMicroSeconds Position in microseconds relative to the start of the resource - only set if the sync update set function was called with the microseconds parameter set. TInt64 aMicroBeats Position in microbeats relative to the start of the resource - only set if the sync update set function was called with the microbeats parameter set and the microseconds parameter set to 0.

virtual void MmcuoMetaDataEntryFound(const TInt aMetaDataEntryId, const TTimeIntervalMicroSeconds &aPosition)=0;

Description

A timed meta data entry has been found in the MIDI data stream, eg a timed song lyric in an SMF file.

Parameters

const TInt aMetaDataEntryId Index of the meta data entry - if this entry has not been encountere before, it will be added to the list of meta data entries. Previously encountered timed entries still generate this callback. const TTimeIntervalMicroSeconds &aPosition Position in microseconds relative to the start of the MIDI resource that the MIDI meta data entry was found at.

virtual void MmcuoMipMessageReceived(const RArray< TMipMessageEntry > &aMessage)=0;

Description

A MIP message has been found in the MIDI data stream.

Parameters

const RArray< TMipMessageEntry > &aMessage Reference to an array of MIP message entries (logical {channel, MIP} value pairs) contained in the message.

virtual void MmcuoPolyphonyChanged(TInt aNewPolyphony)=0;

Description

The polyphony of the MIDI engine has changed.

Parameters

TInt aNewPolyphony The new polyphony value.

virtual void MmcuoInstrumentChanged(TInt aChannel, TInt aBankId, TInt aInstrumentId)=0;

Description

An instrument has been changed on a channel.

Parameters

TInt aChannel Channel where the change of instrument occurred. 0 <= aChannel < ChannelsSupportedL(). TInt aBankId Identifier of the bank that the instrument belongs to, occupying no more than 14 bits. The bank ID is a concatenation of MIDI bank MSB and LSB values. TInt aInstrumentId Identifier of the instrument that has been changed. 0 <= aInstrumentId <= 127.