1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#import <Foundation/Foundation.h>
18
19@class MIDIClient;
20@class MIDIDestination;
21@class MIDISource;
22
23extern NSString * const MIDIClientErrorDomain;
24
25/**
26 * Callbacks for MIDIClient changes.
27 *
28 * Note that these methods may not be called on the main thread.
29 */
30@protocol MIDIClientDelegate <NSObject>
31/** Called when a MIDIClient receives data from a connected source. */
32- (void)MIDIClient:(MIDIClient *)client receivedData:(NSData *)message;
33
34@optional
35/** Called when a MIDI I/O error occurs on the client's endpoints. */
36- (void)MIDIClient:(MIDIClient *)client receivedError:(NSError *)error;
37
38/** Called when a MIDI endpoint has been added to the system. */
39- (void)MIDIClientEndpointAdded:(MIDIClient *)client;
40
41/** Called when a MIDI endpoint has been removed to the system. */
42- (void)MIDIClientEndpointRemoved:(MIDIClient *)client;
43
44/** Called when the configuration of a MIDI object attached to the system has changed. */
45- (void)MIDIClientConfigurationChanged:(MIDIClient *)client;
46@end
47
48/** A MIDI client that can read data from a MIDI source and write data to a MIDI destination. */
49@interface MIDIClient : NSObject
50/** The source attached by -connectToSource:error:. */
51@property (readonly, nonatomic) MIDISource *source;
52
53/** The destination attached by -connectToDestination:error:. */
54@property (readonly, nonatomic) MIDIDestination *destination;
55
56@property (nonatomic, weak) id<MIDIClientDelegate> delegate;
57
58/**
59 * Creates a new MIDI client with a friendly name.
60 *
61 * If an error occurs, nil is returned and the error is populated with a description of the issue.
62 */
63- (instancetype)initWithName:(NSString *)name error:(NSError **)error;
64
65/** Attaches an input source to the client. */
66- (BOOL)connectToSource:(MIDISource *)source error:(NSError **)error;
67
68/** Attaches an output destination to the client. */
69- (BOOL)connectToDestination:(MIDIDestination *)destination error:(NSError **)error;
70
71/** Sends a MIDI packet of data to the client's output destination. */
72- (BOOL)sendData:(NSData *)data error:(NSError **)error;
73@end
74