/* * Copyright (c) 1998, 2004, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.sound.midi; /** * A MidiChannel object represents a single MIDI channel. * Generally, each MidiChannel method processes a like-named MIDI * "channel voice" or "channel mode" message as defined by the MIDI specification. However, * MidiChannel adds some "get" methods that retrieve the value * most recently set by one of the standard MIDI channel messages. Similarly, * methods for per-channel solo and mute have been added. *

* A {@link Synthesizer} object has a collection * of MidiChannels, usually one for each of the 16 channels * prescribed by the MIDI 1.0 specification. The Synthesizer * generates sound when its MidiChannels receive * noteOn messages. *

* See the MIDI 1.0 Specification for more information about the prescribed * behavior of the MIDI channel messages, which are not exhaustively * documented here. The specification is titled MIDI Reference: * The Complete MIDI 1.0 Detailed Specification, and is published by * the MIDI Manufacturer's Association ( * http://www.midi.org). *

* MIDI was originally a protocol for reporting the gestures of a keyboard * musician. This genesis is visible in the MidiChannel API, which * preserves such MIDI concepts as key number, key velocity, and key pressure. * It should be understood that the MIDI data does not necessarily originate * with a keyboard player (the source could be a different kind of musician, or * software). Some devices might generate constant values for velocity * and pressure, regardless of how the note was performed. * Also, the MIDI specification often leaves it up to the * synthesizer to use the data in the way the implementor sees fit. For * example, velocity data need not always be mapped to volume and/or brightness. * * @see Synthesizer#getChannels * * @author David Rivas * @author Kara Kytle */ public interface MidiChannel { /** * Starts the specified note sounding. The key-down velocity * usually controls the note's volume and/or brightness. * If velocity is zero, this method instead acts like * {@link #noteOff(int)}, terminating the note. * * @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C) * @param velocity the speed with which the key was depressed * * @see #noteOff(int, int) */ public void noteOn(int noteNumber, int velocity); /** * Turns the specified note off. The key-up velocity, if not ignored, can * be used to affect how quickly the note decays. * In any case, the note might not die away instantaneously; its decay * rate is determined by the internals of the Instrument. * If the Hold Pedal (a controller; see * {@link #controlChange(int, int) controlChange}) * is down, the effect of this method is deferred until the pedal is * released. * * * @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C) * @param velocity the speed with which the key was released * * @see #noteOff(int) * @see #noteOn * @see #allNotesOff * @see #allSoundOff */ public void noteOff(int noteNumber, int velocity); /** * Turns the specified note off. * * @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C) * * @see #noteOff(int, int) */ public void noteOff(int noteNumber); /** * Reacts to a change in the specified note's key pressure. * Polyphonic key pressure * allows a keyboard player to press multiple keys simultaneously, each * with a different amount of pressure. The pressure, if not ignored, * is typically used to vary such features as the volume, brightness, * or vibrato of the note. * * It is possible that the underlying synthesizer * does not support this MIDI message. In order * to verify that setPolyPressure * was successful, use getPolyPressure. * * @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C) * @param pressure value for the specified key, from 0 to 127 (127 = * maximum pressure) * * @see #getPolyPressure(int) */ public void setPolyPressure(int noteNumber, int pressure); /** * Obtains the pressure with which the specified key is being depressed. * * @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C) * * If the device does not support setting poly pressure, * this method always returns 0. Calling * setPolyPressure will have no effect then. * * @return the amount of pressure for that note, from 0 to 127 * (127 = maximum pressure) * * @see #setPolyPressure(int, int) */ public int getPolyPressure(int noteNumber); /** * Reacts to a change in the keyboard pressure. Channel * pressure indicates how hard the keyboard player is depressing * the entire keyboard. This can be the maximum or * average of the per-key pressure-sensor values, as set by * setPolyPressure. More commonly, it is a measurement of * a single sensor on a device that doesn't implement polyphonic key * pressure. Pressure can be used to control various aspects of the sound, * as described under {@link #setPolyPressure(int, int) setPolyPressure}. * * It is possible that the underlying synthesizer * does not support this MIDI message. In order * to verify that setChannelPressure * was successful, use getChannelPressure. * * @param pressure the pressure with which the keyboard is being depressed, * from 0 to 127 (127 = maximum pressure) * @see #setPolyPressure(int, int) * @see #getChannelPressure */ public void setChannelPressure(int pressure); /** * Obtains the channel's keyboard pressure. * If the device does not support setting channel pressure, * this method always returns 0. Calling * setChannelPressure will have no effect then. * * @return the amount of pressure for that note, * from 0 to 127 (127 = maximum pressure) * * @see #setChannelPressure(int) */ public int getChannelPressure(); /** * Reacts to a change in the specified controller's value. A controller * is some control other than a keyboard key, such as a * switch, slider, pedal, wheel, or breath-pressure sensor. * The MIDI 1.0 Specification provides standard numbers for typical * controllers on MIDI devices, and describes the intended effect * for some of the controllers. * The way in which an * Instrument reacts to a controller change may be * specific to the Instrument. *

* The MIDI 1.0 Specification defines both 7-bit controllers * and 14-bit controllers. Continuous controllers, such * as wheels and sliders, typically have 14 bits (two MIDI bytes), * while discrete controllers, such as switches, typically have 7 bits * (one MIDI byte). Refer to the specification to see the * expected resolution for each type of control. *

* Controllers 64 through 95 (0x40 - 0x5F) allow 7-bit precision. * The value of a 7-bit controller is set completely by the * value argument. An additional set of controllers * provide 14-bit precision by using two controller numbers, one * for the most significant 7 bits and another for the least significant * 7 bits. Controller numbers 0 through 31 (0x00 - 0x1F) control the * most significant 7 bits of 14-bit controllers; controller numbers * 32 through 63 (0x20 - 0x3F) control the least significant 7 bits of * these controllers. For example, controller number 7 (0x07) controls * the upper 7 bits of the channel volume controller, and controller * number 39 (0x27) controls the lower 7 bits. * The value of a 14-bit controller is determined * by the interaction of the two halves. When the most significant 7 bits * of a controller are set (using controller numbers 0 through 31), the * lower 7 bits are automatically set to 0. The corresponding controller * number for the lower 7 bits may then be used to further modulate the * controller value. * * It is possible that the underlying synthesizer * does not support a specific controller message. In order * to verify that a call to controlChange * was successful, use getController. * * @param controller the controller number (0 to 127; see the MIDI * 1.0 Specification for the interpretation) * @param value the value to which the specified controller is changed (0 to 127) * * @see #getController(int) */ public void controlChange(int controller, int value); /** * Obtains the current value of the specified controller. The return * value is represented with 7 bits. For 14-bit controllers, the MSB and * LSB controller value needs to be obtained separately. For example, * the 14-bit value of the volume controller can be calculated by * multiplying the value of controller 7 (0x07, channel volume MSB) * with 128 and adding the * value of controller 39 (0x27, channel volume LSB). * * If the device does not support setting a specific controller, * this method returns 0 for that controller. * Calling controlChange will have no effect then. * * @param controller the number of the controller whose value is desired. * The allowed range is 0-127; see the MIDI * 1.0 Specification for the interpretation. * * @return the current value of the specified controller (0 to 127) * * @see #controlChange(int, int) */ public int getController(int controller); /** * Changes a program (patch). This selects a specific * instrument from the currently selected bank of instruments. *

* The MIDI specification does not * dictate whether notes that are already sounding should switch * to the new instrument (timbre) or continue with their original timbre * until terminated by a note-off. *

* The program number is zero-based (expressed from 0 to 127). * Note that MIDI hardware displays and literature about MIDI * typically use the range 1 to 128 instead. * * It is possible that the underlying synthesizer * does not support a specific program. In order * to verify that a call to programChange * was successful, use getProgram. * * @param program the program number to switch to (0 to 127) * * @see #programChange(int, int) * @see #getProgram() */ public void programChange(int program); /** * Changes the program using bank and program (patch) numbers. * * It is possible that the underlying synthesizer * does not support a specific bank, or program. In order * to verify that a call to programChange * was successful, use getProgram and * getController. * Since banks are changed by way of control changes, * you can verify the current bank with the following * statement: *

     *   int bank = (getController(0) * 128)
     *              + getController(32);
     * 
* * @param bank the bank number to switch to (0 to 16383) * @param program the program (patch) to use in the specified bank (0 to 127) * @see #programChange(int) * @see #getProgram() */ public void programChange(int bank, int program); /** * Obtains the current program number for this channel. * @return the program number of the currently selected patch * @see Patch#getProgram * @see Synthesizer#loadInstrument * @see #programChange(int) */ public int getProgram(); /** * Changes the pitch offset for all notes on this channel. * This affects all currently sounding notes as well as subsequent ones. * (For pitch bend to cease, the value needs to be reset to the * center position.) *

The MIDI specification * stipulates that pitch bend be a 14-bit value, where zero * is maximum downward bend, 16383 is maximum upward bend, and * 8192 is the center (no pitch bend). The actual * amount of pitch change is not specified; it can be changed by * a pitch-bend sensitivity setting. However, the General MIDI * specification says that the default range should be two semitones * up and down from center. * * It is possible that the underlying synthesizer * does not support this MIDI message. In order * to verify that setPitchBend * was successful, use getPitchBend. * * @param bend the amount of pitch change, as a nonnegative 14-bit value * (8192 = no bend) * * @see #getPitchBend */ public void setPitchBend(int bend); /** * Obtains the upward or downward pitch offset for this channel. * If the device does not support setting pitch bend, * this method always returns 8192. Calling * setPitchBend will have no effect then. * * @return bend amount, as a nonnegative 14-bit value (8192 = no bend) * * @see #setPitchBend(int) */ public int getPitchBend(); /** * Resets all the implemented controllers to their default values. * * @see #controlChange(int, int) */ public void resetAllControllers(); /** * Turns off all notes that are currently sounding on this channel. * The notes might not die away instantaneously; their decay * rate is determined by the internals of the Instrument. * If the Hold Pedal controller (see * {@link #controlChange(int, int) controlChange}) * is down, the effect of this method is deferred until the pedal is * released. * * @see #allSoundOff * @see #noteOff(int) */ public void allNotesOff(); /** * Immediately turns off all sounding notes on this channel, ignoring the * state of the Hold Pedal and the internal decay rate of the current * Instrument. * * @see #allNotesOff */ public void allSoundOff(); /** * Turns local control on or off. The default is for local control * to be on. The "on" setting means that if a device is capable * of both synthesizing sound and transmitting MIDI messages, * it will synthesize sound in response to the note-on and * note-off messages that it itself transmits. It will also respond * to messages received from other transmitting devices. * The "off" setting means that the synthesizer will ignore its * own transmitted MIDI messages, but not those received from other devices. * * It is possible that the underlying synthesizer * does not support local control. In order * to verify that a call to localControl * was successful, check the return value. * * @param on true to turn local control on, false * to turn local control off * @return the new local-control value, or false * if local control is not supported * */ public boolean localControl(boolean on); /** * Turns mono mode on or off. In mono mode, the channel synthesizes * only one note at a time. In poly mode (identical to mono mode off), * the channel can synthesize multiple notes simultaneously. * The default is mono off (poly mode on). *

* "Mono" is short for the word "monophonic," which in this context * is opposed to the word "polyphonic" and refers to a single synthesizer * voice per MIDI channel. It * has nothing to do with how many audio channels there might be * (as in "monophonic" versus "stereophonic" recordings). * * It is possible that the underlying synthesizer * does not support mono mode. In order * to verify that a call to setMono * was successful, use getMono. * * @param on true to turn mono mode on, false to * turn it off (which means turning poly mode on). * * @see #getMono * @see VoiceStatus */ public void setMono(boolean on); /** * Obtains the current mono/poly mode. * Synthesizers that do not allow changing mono/poly mode * will always return the same value, regardless * of calls to setMono. * @return true if mono mode is on, otherwise * false (meaning poly mode is on). * * @see #setMono(boolean) */ public boolean getMono(); /** * Turns omni mode on or off. In omni mode, the channel responds * to messages sent on all channels. When omni is off, the channel * responds only to messages sent on its channel number. * The default is omni off. * * It is possible that the underlying synthesizer * does not support omni mode. In order * to verify that setOmni * was successful, use getOmni. * * @param on true to turn omni mode on, false to * turn it off. * * @see #getOmni * @see VoiceStatus */ public void setOmni(boolean on); /** * Obtains the current omni mode. * Synthesizers that do not allow changing the omni mode * will always return the same value, regardless * of calls to setOmni. * @return true if omni mode is on, otherwise * false (meaning omni mode is off). * * @see #setOmni(boolean) */ public boolean getOmni(); /** * Sets the mute state for this channel. A value of * true means the channel is to be muted, false * means the channel can sound (if other channels are not soloed). *

* Unlike {@link #allSoundOff()}, this method * applies to only a specific channel, not to all channels. Further, it * silences not only currently sounding notes, but also subsequently * received notes. * * It is possible that the underlying synthesizer * does not support muting channels. In order * to verify that a call to setMute * was successful, use getMute. * * @param mute the new mute state * * @see #getMute * @see #setSolo(boolean) */ public void setMute(boolean mute); /** * Obtains the current mute state for this channel. * If the underlying synthesizer does not support * muting this channel, this method always returns * false. * * @return true the channel is muted, * or false if not * * @see #setMute(boolean) */ public boolean getMute(); /** * Sets the solo state for this channel. * If solo is true only this channel * and other soloed channels will sound. If solo * is false then only other soloed channels will * sound, unless no channels are soloed, in which case all * unmuted channels will sound. * * It is possible that the underlying synthesizer * does not support solo channels. In order * to verify that a call to setSolo * was successful, use getSolo. * * @param soloState new solo state for the channel * @see #getSolo() */ public void setSolo(boolean soloState); /** * Obtains the current solo state for this channel. * If the underlying synthesizer does not support * solo on this channel, this method always returns * false. * * @return true the channel is solo, * or false if not * * @see #setSolo(boolean) */ public boolean getSolo(); }