1 /*
2  *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #import <Foundation/Foundation.h>
12 
13 #import "RTCMacros.h"
14 
15 NS_ASSUME_NONNULL_BEGIN
16 
17 RTC_OBJC_EXPORT
18 @protocol RTC_OBJC_TYPE
19 (RTCDtmfSender)<NSObject>
20 
21     /**
22      * Returns true if this RTCDtmfSender is capable of sending DTMF. Otherwise
23      * returns false. To be able to send DTMF, the associated RTCRtpSender must be
24      * able to send packets, and a "telephone-event" codec must be negotiated.
25      */
26     @property(nonatomic, readonly) BOOL canInsertDtmf;
27 
28 /**
29  * Queues a task that sends the DTMF tones. The tones parameter is treated
30  * as a series of characters. The characters 0 through 9, A through D, #, and *
31  * generate the associated DTMF tones. The characters a to d are equivalent
32  * to A to D. The character ',' indicates a delay of 2 seconds before
33  * processing the next character in the tones parameter.
34  *
35  * Unrecognized characters are ignored.
36  *
37  * @param duration The parameter indicates the duration to use for each
38  * character passed in the tones parameter. The duration cannot be more
39  * than 6000 or less than 70 ms.
40  *
41  * @param interToneGap The parameter indicates the gap between tones.
42  * This parameter must be at least 50 ms but should be as short as
43  * possible.
44  *
45  * If InsertDtmf is called on the same object while an existing task for this
46  * object to generate DTMF is still running, the previous task is canceled.
47  * Returns true on success and false on failure.
48  */
49 - (BOOL)insertDtmf:(nonnull NSString *)tones
50           duration:(NSTimeInterval)duration
51       interToneGap:(NSTimeInterval)interToneGap;
52 
53 /** The tones remaining to be played out */
54 - (nonnull NSString *)remainingTones;
55 
56 /**
57  * The current tone duration value. This value will be the value last set via the
58  * insertDtmf method, or the default value of 100 ms if insertDtmf was never called.
59  */
60 - (NSTimeInterval)duration;
61 
62 /**
63  * The current value of the between-tone gap. This value will be the value last set
64  * via the insertDtmf() method, or the default value of 50 ms if insertDtmf() was never
65  * called.
66  */
67 - (NSTimeInterval)interToneGap;
68 
69 @end
70 
71 NS_ASSUME_NONNULL_END
72